Life cycle assessment of mussel and turbot aquaculture: application and insights
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UNIVERSIDADE DE SANTIAGO DE COMPOSTELA Departamento de Enxeñaría Química LIFE CYCLE ASSESSMET OF MUSSEL AD TURBOT AQUACULTURE Application and insights Memoria presentada por: Diego Iribarren Lorenzo Para optar al grado de Doctor por la Universidad de Santiago de Compostela Santiago de Compostela, marzo 2010
UNIVERSIDADE DE SANTIAGO DE COMPOSTELA Departamento de Enxeñaría Química D. Gumersindo Feijoo Costa, Catedrático de Ingeniería Química, y Dña. María Teresa Moreira Vilar, Profesora Titular de Ingeniería Química, ambos de la Universidad de Santiago de Compostela, Informan: Que la memoria titulada “Life Cycle Assessment of mussel and turbot aquaculture. Application and insights” que, para optar al grado de Doctor en Ingeniería Química, Programa de Doctorado en Ingeniería Química y Ambiental, presenta D. Diego Iribarren Lorenzo, ha sido realizada bajo nuestra inmediata dirección en el Departamento de Ingeniería Química de la Universidad de Santiago de Compostela.
Esta memoria fue defendida el viernes 12 de marzo de 2010 en el Salón de Actos de la Escuela Técnica Superior de Ingeniería de la Universidad de Santiago de Compostela, ante el Tribunal compuesto por: Dr. José Mario Díaz Fernández. Departamento de Ingeniería Química y Tecnología del Medio Ambiente. Universidad de Oviedo. Dr. Joan Rieradevall Pons. Departamento de Ingeniería Química. Universidad Autónoma de Barcelona. Dr. Francesc Castells Piqué. Departamento de Ingeniería Química. Universidad Rovira i Virgili. Dr. Francesc Hernández Sancho. Departamento de Estructura Económica. Universidad de Valencia. Dr. Juan Manuel Lema Rodicio. Departamento de Ingeniería Química. Universidad de Santiago de Compostela. Calificación: Sobresaliente Cum Laude.
To my wife, parents and sister
Abstract The path towards sustainability in the food sector demands the modification of the current operational and environmental patterns. In this sense, it is necessary to pursue reductions in the consumption levels for materials and energy, as well as the mitigation of the corresponding environmental impacts. Environmental management tools assist companies to monitor, manage and improve their environmental performance as well as to integrate environmental, economic and social issues. These tools enable the implementation of eco-efficiency strategies, life cycle thinking and environmental management systems into the business network. In particular, Life Cycle Assessment (LCA) is a well-known technique for assessing the potential impacts associated with a product. One of the sectors where LCA has been widely implemented is the agri-food sector. However, while LCA in agriculture is quite well established, the use of this tool to assess seafood production systems is a more recent phenomenon. This doctoral thesis contributes to widen the range of seafood species studied under an LCA approach. Furthermore, this dissertation develops new trends in LCA of seafood such as the combined application of LCA and Data Envelopment Analysis (DEA), or the implementation of Carbon Footprinting (CF) schemes. The Galician fishing sector is a key economic branch in Spain. Within this sector, there is an activity where Galicia arises as the national leader. This is the Galician aquaculture, which can be understood as a sector itself. This dissertation evaluates two reference species in the Galician extensive and intensive aquaculture: mussels (Mytilus galloprovincialis) and turbot (Scophthalmus maximus), respectively. The novel application of LCA to the mussel sector comprises a range of activities which can be grouped into four sub-sectors: mussel culture, dispatch centres, canning factories and cooking plants. Detailed inventories are presented for mussel farming, processing and consumption, as well as for the management systems regarding the valorization of mussel shells and mussel organic remains. From the environmental characterization of the Galician mussel sector, the main hot spots are identified and potential improvements are then proposed. The role of
Index iv 5.4.3. Implementation into the mussel case study ...................................... 141 5.5. Conclusions, recommendations and perspectives .................................... 142 5.6. References ................................................................................................ 143 SECTIO III. APPLICATIO OF LIFE CYCLE ASSESSMET I ITESIVE AQUACULTURE. THE TURBOT SECTOR Chapter 6: Life Cycle Assessment of feed for aquaculture ........................... 147 Summary ......................................................................................................... 147 6.1. Introduction .............................................................................................. 149 6.2. Methods .................................................................................................... 150 6.2.1. System boundaries ............................................................................ 150 6.2.2. Functional unit .................................................................................. 152 6.2.3. Data acquisition and assumptions ..................................................... 152 6.2.4. Life cycle inventory .......................................................................... 153 6.3. Results ...................................................................................................... 155 6.4. Discussion and identification of improvement potentials ........................ 158 6.5. Conclusions, recommendations and perspectives .................................... 159 6.6. References ................................................................................................ 159 Chapter 7: Life Cycle Assessment of the turbot sector ................................. 163 Summary ......................................................................................................... 163 7.1. Introduction .............................................................................................. 165 7.2. Methods .................................................................................................... 166 7.2.1. System boundaries ............................................................................ 167 7.2.2. Functional unit .................................................................................. 168 7.2.3. Data acquisition and assumptions ..................................................... 168 7.2.4. Life cycle inventory .......................................................................... 169 7.3. Results ...................................................................................................... 172
Index v 7.4. Discussion and identification of improvement potentials ........................ 175 7.4.1. Turbot aquaculture ............................................................................ 175 7.4.2. Comparison of aquaculture sectors ................................................... 176 7.5. Conclusions, recommendations and perspectives .................................... 177 7.6. References ................................................................................................ 178 SECTIO IV. ISIGHTS I THE APPLICATIO OF LIFE CYCLE ASSESSMET Chapter 8: The link between operational efficiency and environmental impacts ............................................................................................................... 183 Summary ......................................................................................................... 183 8.1. Introduction .............................................................................................. 185 8.1.1. The problem of multiple inventory data in LCA .............................. 185 8.1.2. An introduction to DEA .................................................................... 185 8.2. Proposal of an LCA+DEA approach ....................................................... 187 8.2.1. The five-step LCA+DEA method ..................................................... 187 8.2.2. Before performing DEA ................................................................... 188 8.2.3. Potentials of the LCA+DEA method ................................................ 190 8.3. Application to mussel cultivation sites .................................................... 191 8.3.1. Introduction to DEA for mussel cultivation sites.............................. 192 8.3.2. Application of the five-step LCA+DEA approach ........................... 197 8.4. Conclusions .............................................................................................. 207 8.5. References ................................................................................................ 208 Chapter 9: Environmental impact efficiency ................................................. 211 Summary ......................................................................................................... 211 9.1. Introduction .............................................................................................. 213 9.2. LCA+DEA framework ............................................................................. 214 9.2.1. The three-step LCA+DEA method ................................................... 214
Index vi 9.2.2. LCA summary................................................................................... 215 9.2.3. DEA framework ................................................................................ 216 9.3. Application to mussel cultivation sites .................................................... 220 9.4. Conclusions .............................................................................................. 232 9.5. References ................................................................................................ 233 Chapter 10: Assessment of the carbon footprint ............................................ 235 Summary ......................................................................................................... 235 10.1. Introduction ............................................................................................ 237 10.1.1. Carbon Footprinting and Life Cycle Assessment ........................... 237 10.1.2. CF applications and implications .................................................... 238 10.2. Justification and presentation of the case study ..................................... 240 10.3. Application to canned mussels ............................................................... 241 10.3.1. Method adopted for the CF of canned mussels ............................... 241 10.3.2. Calculation of the carbon footprint for canned mussels ................. 242 10.4. Discussion .............................................................................................. 251 10.5. Conclusions and perspectives ................................................................ 254 10.6. References .............................................................................................. 254 SECTIO V. GEERAL COCLUSIOS Chapter 11: General conclusions ..................................................................... 261 ADDITIOAL COTETS Annex I: Resumen .................................................................................................. i Annex II: Resumo ................................................................................................ ix Annex III: Curriculum Vitae ........................................................................... xvii Acronyms ........................................................................................................... xxv Acknowledgements ......................................................................................... xxvii
SECTIO I. ITRODUCTIO TO THE STUDY
Introduction to the Galician aquaculture sector 3 Chapter 1 Introduction to the Galician aquaculture sector Summary This first chapter tries to contextualize the doctoral thesis within the Galician aquaculture sector. The role of this sector inside the food industry framework is discussed and some economic data are provided. The mussel sector is presented as the main representative of the Spanish extensive aquaculture. A description of this sector is detailed by focusing on the Galician experience due to its outstanding position in the mussel market from a worldwide perspective. On the other hand, the national intensive aquaculture of marine fish is here represented by the turbot sector. Once again, Galicia sets itself up as a key region in the cultivation and commercialization of this seafood, not only from a national scale but also from an international scope.
Chapter 1 4 Index 1.1. The food industry in Spain and Galicia ........................................................... 5 1.2. The Galician aquaculture sector ....................................................................... 7 1.2.1. An introduction to aquaculture ................................................................. 8 1.2.2. Aquaculture in Galicia ............................................................................ 10 1.3. The mussel sector ........................................................................................... 12 1.4. The turbot sector ............................................................................................ 16 1.5. References ...................................................................................................... 19
Introduction to the Galician aquaculture sector 5 1.1. The food industry in Spain and Galicia The net sales of products from food industry in Spain accounted for more than 78,000 million euros in 2007 (Sainz et al. 2008). This value meant a percentage over 14% of the total net sales for the Spanish industrial sector. Table 1.1 gathers the main information concerning the Spanish food industry. As observed, the role of the seafood branch within the food industry cannot be ignored since it contributed with a percentage of 5% to the net sales of products as well as to the consumption of raw materials and to the number of employees. Table 1.1. Basic information for the food industry in Spain in 2007 (adapted from Sainz et al. 2008) Sector et sales of products Consumption of raw materials Employees Million € % Million € % umber % Meat industry 15,904.67 20.20 10,542.63 23.84 85,624 22.41 Seafood transformation 3,626.50 4.61 2,257.92 5.10 22,248 5.82 Canned fruits and vegetables 6,265.58 7.96 3,316.63 7.50 35,410 9.27 Fats and oils 6,225.30 7.91 5,089.52 11.51 10,860 2.84 Dairy industry 8,603.54 10.93 4,597.10 10.40 28,069 7.34 Mill products 2,637.75 3.35 1,928.34 4.36 6,879 1.80 Animal feed products 6,853.37 8.71 5,094.98 11.52 14,124 3.70 Bread, cakes and biscuits 6,044.94 7.68 2,218.94 5.02 84,704 22.17 Sugar, chocolate and confectionery 3,228.34 4.10 1,437.75 3.25 17,779 4.65 Water 5,067.11 6.43 1,990.44 4.50 14,985 3.92 Beer and stout 3,052.52 3.88 495,51 1.12 7,855 2.05 Wine 5,319.62 6.75 2,439.58 5.52 22,863 5.98 Other alcoholic beverages 1,690.88 2.15 1,064.09 2.41 5,327 1.39 Other products 4,205.92 5.34 1,747.98 3.95 25,444 6.66 TOTAL 78,726.04 100.00 44.221,41 100.00 382,171 100.00
Chapter 1 6 It is also interesting to highlight the relevance of Research and Development (R&D) within the Spanish food industry. Thus, Figure 1.1 shows the distribution of novel products among the different sectors in 2007. As captured in this figure, there are relevant percentages associated with sectors where seafood is involved: frozen food (13.7%), refrigerated seafood (2.9%) and canned food (2.1%). Dry food Frozen food Dairy products Non - alcoholic beverages Alcoholic beverages Meat products Refrigerated solutions Atmosphere solutions Refrigerated seafood Fruits and vegetables Canned food Figure 1.1. R&D in the Spanish food industry in 2007 (adapted from Sainz et al. 2008) Turning to a regional scope, the food industry in Galicia (NW Spain) accounted in 2007 for 17% of the employees in the total industry sector, with around 29,000 employees. Moreover, when referring to the net sales of products, this percentage was of 18%, with more than 5,500 million euros. On the other hand, the consumption of raw materials in the Galician food industry involved 3,250 million euros, and the number of companies in this sector exceeded 2,600 (Sainz et al. 2008). With respect to the economic turnover and the number of employees, seafood transformation was the industrial branch with the greatest contribution: around 2,000 million euros and more than 10,500 employees. Finally, regarding the national food industry, Galicia accounted for more than 7% of the sales, with a similar percentage for the consumption of raw materials and with 8% of the employees.
Introduction to the Galician aquaculture sector 7 1.2. The Galician aquaculture sector The Galician fishing sector is the most important one in Spain. Its economic turnover exceeded 1,100 million euros in 2007, with a contribution over 10% to the regional gross domestic product (Sainz et al. 2008; Xunta de Galicia 2008a). Moreover, it is assumed that each direct employment within fishing activities involves four jobs inland. The Galician fishing fleet is made up of more than 6,000 vessels, which means more than 40% of the national fishing fleet. Over 1,000 of these vessels are devoted to aquaculture. The main commercialized species are sardine, horse mackerel, hake, turbot, mussels and other bivalves (cockles and clams), crustaceans (crayfish, barnacle, spider crab, etc.) and cephalopods (octopus and squid). The Galician fishing sector consists of fishing, aquaculture and shellfishing. These branches support the seafood canning and freezing industry and, partly, the naval construction oriented to the construction, repair and maintenance of vessels. In addition to these activities, this sector also plays a role in the logistical distribution of seafood to the rest of Spain and other international destinations. This set of activities shapes an open complex with a strong exporting projection (Fernández & Fernández-Grela 2003; Fernández 2006). Within the Galician fishing sector, the following industrial sub-sectors are highlighted (MAPA 2007a): Seafood canning. It is an activity oriented to export and is located along the Galician coast, mainly in the rias of Arousa and Vigo. According to data for number of establishments, production, turnover and number of employees, the relevance of the canning industry in Galicia is undeniable (ANFACO 2007). Currently, the Galician companies dominate the Spanish market and they are the reference in the European Union. In fact, around half of the national companies devoted to seafood canning are found in Galicia. In 2007, the Galician seafood canning sub-sector presented a production level close to 300,000 tonnes (85% of the total production in Spain), with the canning companies accounting for a turnover of more than 1,000 million euros and creating around 12,000 jobs.
Chapter 1 14 As previously stated, activities related to the Spanish mussel sector are primarily located in Galicia where mussels are the single largest cultured shellfish and entail a strong impact on the Galician economy. Rafts are the most common mussel cultivation system in Spain (Figure 1.5). A raft is defined as any floating structure constructed of wood or reeds, kept afloat using any combination of buoyant materials such as wood, sealed barrels, inflated air chambers or extruded polystyrene blocks. The main components of the raft are the grid (mesh of wooden beams), the flotation system, the anchoring system (shackle chain and concrete anchoring blocks) and the cultivation system (ropes with plastic pegs) (Tirado & Macias 2006). Figure 1.5. Conventional raft for mussel aquaculture The activities performed in the raft include: Seed collection. Mussel farmers usually collect this seed from two different sources: coastal stock from the rocky shoreline and collector ropes suspended from culture rafts (Labarta et al. 2004). Another possibility consists of the use of netting strips submerged at 1-2 m depth during the reproduction period of the mussel.
Introduction to the Galician aquaculture sector 15 Seed pre-fattening. This operation is performed by attaching small seeds to the ropes with the aid of thin cotton nets. These ropes are submerged in the sea, hanging from the platform (Figueras 1989). Rope thinning. The thinning-out process is carried out when individual mussels reach a size of around 5 cm, generally after 4-6 months (Pérez- Camacho 1992). Three or four new ropes can be obtained from each initial rope, allowing the mussels to grow with a more homogenous shell length and a smaller density of molluscs per rope length until they reach commercial size (7-10 cm). Harvesting and selection. Growing ropes are hauled onto boats with hydraulic cranes and they are stripped of their mussels. Afterwards, the clumps of mussels are separated, washed with seawater, classified according to shell length and then bagged. However, the mussel sector in Galicia is not limited to mussel farming. In fact, the Galician aquaculture of mussels (Mytilus Galloprovincialis) gives rise to a complex sector involving not only cultivation tasks but also a variety of processing activities. These activities are performed by different economic actors depending on the processing alternative selected for mussel transformation. Thus, the role performed by the supplier companies implies an annual turnover of 8 million euros and 530 jobs, while dispatch centres have an annual turnover of 87 million euros and 500 jobs. Finally, mussel processing factories present a turnover of 66 million euros, providing 900 jobs (Franco 2006). Three main sub-sectors can be assumed according to the centres where mussel transformation takes place (Iribarren et al. 2010b): Dispatch centres sub-sector. This branch is responsible for the fresh mussel market. A dispatch centre is any on-shore or off-shore establishment for the reception, conditioning, washing, cleaning, grading, wrapping and packaging of fresh molluscs for human consumption. The purification process consists of the maintenance of the molluscs for a certain period of time (at least 42 h) in water free of pathogens, so that these molluscs filter the water and get depurated (Amengual 1989). There are many agents and procedures to remove pathogens in seawater, being chlorine gas the most extended alternative worldwide (Plataforma Tecnolóxica 2007).
Chapter 1 16 Canning factories sub-sector. Galicia produces more than 80% of the canned seafood in Spain, with a marked position for tuna (Hospido & Tyedmers 2005), sardine and mussel. This latter is the most representative and commercialized mollusc in the Spanish market; around 73% of Spanish families consumes this product (Illescas et al. 2007). This second cluster produces canned mussels using mussels transported from the cultivation sites as the main raw material. Canning factories carry out a wide range of operations that could be sorted out as follows (Xunta de Galicia 2005): initial operations (mussel reception, washing and sieving, de-clumping, trimming, etc.), processing operations (cooking, mussel flesh separation, byssus removal, size grading, dehydrating, packaging, liquid dosage and filling, etc.), final operations (sealing, washing, codification, sterilization, washing and drying, cartoning and packaging, and storage) and ancillary operations (wastewater treatment, bathroom fittings, machinery maintenance, general cleaning, boilers and central heating). Mussel cooking plants sub-sector. This third group supplies several types of boiled mussel products. Two main categories are distinguished: frozen boiled mussels and canned mussels produced from boiled mussels. These two categories have the same intermediate product, i.e. the boiled mussel flesh, but different subsequent operations. Refrigerated/frozen boiled mussels are produced in cooking-freezing facilities, while canned mussels are usually produced in partial canning factories which process boiled mussel flesh coming from cooking plants. The several components of each sub-sector will be detailed in subsequent chapters of this dissertation. 1.4. The turbot sector The turbot sector mainly involves farms where intensive aquaculture practices are performed. Nevertheless, there are other components which play an essential role within the Galician turbot sector, as captured in Figure 1.6. These components include: (i) feeds, (ii) equipment, (iii) buildings, (iv) chemicals, and (v) energy carriers (Aubin et al. 2006).
Introduction to the Galician aquaculture sector 17 Figure 1.6. Components involved within the turbot sector Regarding fish production, commercial turbot is produced in inland farms with seawater supply. In these facilities, turbot aquaculture is developed according to a set of stages from gamete obtention to final growing for commercial purposes (Garazo 2009). The conventional steps performed in turbot (Scophthalmus maximus) farms are shown in Figure 1.7. Apart from feed production, the processes included in the figure are generally carried out in the concerned turbot farms. The first stage is aimed at gamete obtention for both males and females. In their natural environment, turbots release gametes in spring or summer. However, aquaculture farms have turbot larvae and juveniles all the year because it is possible to induce egg lay by means of exposures at different light periods which promote sperm and ovule release. After six or eight fertilization days, larvae are obtained and they float on the surface of the tanks. Larval development is a critical stage because of mortality. Therefore, in this phase, water quality, oxygen content, diet and physicochemical parameters such as temperature and light are carefully controlled. For instance, water must be filtered, heated and treated with ultraviolet light in order to remove microorganisms which can be detrimental and induce mortality. Larval development is usually performed in black round tanks where culture is Feed processing Ingredient production Transport Production (liquid oxygen, medicines, etc.) Transport FISH PRODUCTION Production in aquaculture farms FEEDS CHEMICALS ENERGY CARRIERS BUILDINGS EQUIPMENT Manufacture Transport Use Transport Production Use Material production and transport Construction Use
Chapter 1 18 developed with individual densities ranging from 30-40 larvae per litre of water. In Spain, intensive culture prevails for larval development. Figure 1.7. Stages in turbot aquaculture farms After egg eclosion and for seven days, larvae feed themselves on the vitelum sack that they have when they are born. Afterwards, the feeding of larvae consists of zooplankton which is produced in the farm itself. Initially, feeding is based on rotifers provided with phytoplankton. Then, they are fed Artemia salina. Larval growth is very rapid and, after 90 days, larvae go from 3 mm and 0.2 g to 35 mm and 2 g. Breeding maintenance Larval culture Hatching and nursing Growing Ongrowing Slaughter Packaging Cold storage Dispatch Auxiliary cultures: microalgae, Artemia , rotifer Feeds
Introduction to the Galician aquaculture sector 19 Turbot is a benthic species with flat shape. During larval development a metamorphosis takes place. This phenomenon begins from day 15 and lasts around 45-60 days. Close to the end of the metamorphosis, larvae are moved to tanks with greater surface and lesser depth. During this growth period, feeding is changed from zooplankton (live feed) to feed (inert feed). This change is called weaning. It takes place when the metamorphosis process is ending. If diets are appropriate, the survival percentages can be greater than 95% for this stage. Growing happens from 0.5-1 g up to 5 g. Turbot juveniles are further developed in tanks with greater surface and lesser height than the initial ones. Physicochemical conditions are similar to those of the previous stage. It is important to keep a proper water renewal and to avoid dead zones in order to prevent diseases associated with waste accumulation. Feeding is feed-based. The ongrowing stage lasts until turbot juveniles reach commercial size (adult turbots). This is the easiest period within the turbot culture. Survival percentages during this phase are the highest ones. Feeding is usually based on feed, just resorting to fresh food (low-value fish like blue whiting) when profitable. This culture stage is carried out in tanks with individual densities around 20-40 kg/m 2 . Fish size grading is a key aspect during this step. After 26-30 months, turbots reach commercial size, i.e. 1.5-2 kg. However, since females grow in a larger extent than males, the latter are usually commercialized when they are around 1 kg in weight. For commercialization, turbots are removed alive from the cultivation tanks. Finally, they undergo a heat shock which leads to death. 1.5. References Ahmed, M.N.U. (2003). “Fisheries in the economy of Bangladesh and development potential”. Fish week compendium 2003, Department of Fisheries, Ministry of Fisheries and Livestock, Dhaka, Bangladesh, 11-15 Amengual, J. (1989). “Mollusc sanitation and marketing in Spain”. Report of the Workshop and Study Tour on Mollusc Sanitation and Marketing, 15-28 October 1989, France
Chapter 1 20 ANFACO (2007). “Datos 2006” (in Spanish). National Association of Canned Seafood and Fish Manufacturers. <www.anfaco.es> Aubin, J., Papatryphon, E., van der Werf, H.M.G., Petit, J., Morvan, Y.M. (2006). “Characterisation of the environmental impact of a turbot (Scophthalmus maximus) re-circulating production system using Life Cycle Assessment”. Aquaculture 261, 1259-1268 Conde, A. (2007). “The Spanish mussel sector”. <www.havbrukskompaniet.no> FAO (2006). “Seafood international. Supplies and markets mussels”. FAO Fishstat, 10 FAO (2007). “Global aquaculture production 1950-2005”. Fisheries and Aquaculture Information and Statistics Service. <www.fao.org> Fernández, M., Fernández-Grela, M. (2003). “La estructura productiva de la economía gallega” (in Spanish). CIEF Caixa Galicia Foundation. Galaxia publisher, Spain Fernández, G. (2006). “Economía rural y agraria en Galicia 2005” (in Spanish). FG Economic and Social Studies, Madrid, Spain Figueras, A.J. (1989). “Mussel culture in Spain and France”. World Aquaculture 20 (4) Franco, M. (2006). “A miticultura en Galicia: unha actividade de éxito e con futuro” (in Galician). Revista Galega de Economía 15 (1), 251-256 Garazo, A. (2009). <www.terralia.com/articulo.php?recordID=1209> Hospido, A., Tyedmers, P. (2005). “Life cycle environmental impacts of Spanish tuna fisheries”. Fish Res 76, 174-186 Illescas, J.L., Bacho, O., Ferrer, S. (2007). “Evolución y tendencias en los mercados de moluscos” (in Spanish). Distribución y consumo, 34-40 Iribarren, D., Moreira, M.T., Feijoo, G. (2010a). “Life Cycle Assessment of mussel culture”. In: “Mussels: Anatomy, Habitat and Environmental Impact”, Nova Science Publishers, New York, USA (in press) Iribarren, D., Moreira, M.T., Feijoo, G. (2010b). “Revisiting the Life Cycle Assessment of mussels from a sectorial perspective”. J Clean Prod 18, 101- 111 Jian-Guang, F., Qisheng, T. (2005). “Development of mussel industry in China”. <www.aquacultureassociation.ca> Josupeit, H. (2005). “Mussel production and markets”. <www.globefish.org>
Introduction to the Galician aquaculture sector 21 Labarta, U., Fernández-Reiriz, M.J., Pérez-Camacho, A., Pérez-Corbacho, E. (2004). “Bateeiros, mar, mejillón. Una perspectiva bioeconómica” (in Spanish). Sectorial Studies, CaixaGalicia Foundation, Spain MAPA – Célula de Promoción y Animación del Desarrollo Rural (2007a). <http://redrural.tragsatec.es/> MAPA (2007b). “Libro Blanco de la Pesca” (in Spanish). Ministry of Agriculture, Fisheries and Food, Spain. <www.mapa.es> Pérez-Camacho, A. (1992). “Cultivo de mejillón en la batea” (in Spanish). Aquaculture books, Xunta de Galicia, Spain Plataforma Tecnolóxica da Pesca, Xunta de Galicia (2007). <www.pescadegalicia.com> Sainz, H., Sanz, A., Vera, D., Martín-Cerdeño, V.J. (2008). “Alimentación en España, 2008. Producción, industria, distribución y consumo” (in Spanish). Empresa Nacional Mercasa – Distribución y Consumo, Madrid, Spain Tirado, C., Macias, J.C. (2006). “Cultivo de mejillón. Aspectos generales y experiencias en Andalucía” (in Spanish). Regional Ministry of Agriculture and Fisheries, Andalucia, Spain Xunta de Galicia (2005). “Autorización Ambiental Integrada - Guía de aplicación nas instalacións destinadas á conserva de peixes e mariscos, 2005” (in Galician). Regional Ministry of the Environment, Galicia, Spain Xunta de Galicia (2008a). “Anuario de Pesca Galicia 2007” (in Galician). Regional Ministry of Fisheries and Sea Affairs, Galicia, Spain Xunta de Galicia (2008b). “Shipbuilding Special Report 2008”. Regional Ministry of Economy and Industry, Galicia, Spain. <www.bygalicia.eu>
Introduction to management tools 23 Chapter 2 Introduction to management tools Summary Once the study has been contextualized, this second chapter presents an overview of the management tools that facilitate the path of business towards sustainable development. The role of environmental management tools to assist companies to monitor, better manage and improve their environmental performance is highlighted. Specifically, Life Cycle Assessment (LCA) is detailed since it was chosen as the environmental management tool to evaluate the mussel and turbot aquaculture sectors from a life cycle perspective. Carbon Footprinting (CF) is also addressed because of its link with LCA and its current popularity in the food sector as a measure to promote climate change mitigation while providing environmental information. Additionally, Data Envelopment Analysis (DEA) is introduced due to its potential to establish proper eco-efficiency targets when used together with LCA. The objectives and structure of this thesis are explained according to the framework established throughout these two chapters.
Chapter 2 30 systematic product management that aims to minimize the environmental and socio-economic burdens associated with a product during its entire life cycle and value chain (UNEP 2007). A life cycle is made up of consecutive interrelated stages of a product system from raw material acquisition (or production from natural resources) to final disposal. Figure 2.2 symbolizes this concept by representing not only the processing of a certain product but also previous and subsequent stages such as production, transport, shopping, consumption and waste management. Figure 2.2. Life cycle concept A wide range of tools, techniques and concepts are available to provide information and data to be used in an LCM system. Among others (CHAINET 2008): (i) check-lists, (ii) cost-benefit analysis, (iii) cumulative energy requirement analysis, (iv) environmental impact assessment, (v) environmental risk assessment, (vi) input-output analysis, (vii) Life Cycle Assessment, (viii) material flow analysis, (ix) material intensity analysis, and (x) multi-criteria analysis. LIFE CYCLE PRODUCTION PROCESSING TRANSPORT SHOPPING CONSUMPTION WASTE MANAGEMENT
Introduction to management tools 31 As previously stated, LCA constitutes a process to evaluate the environmental burdens associated with a product, process or activity by identifying and quantifying energy and materials used and wastes released to the environment, and to evaluate and implement opportunities to affect environmental improvements (Consoli et al. 1993). LCA is one of the tools that have received much attention from both the scientific world and the policy makers. This dissertation discusses the application and potentials of LCA in the aquaculture field. Hence, additional relevant concepts on LCA must be introduced. 2.3.1. Introduction to Life Cycle Assessment LCA tackles the environmental aspects and the potential environmental impacts linked to the entire life cycle of a product, encompassing all stages from cradle to grave: raw material extraction and processing; manufacture, transport and distribution; use; re-use, maintenance; recycling and final disposal. As represented in Figure 2.3, four stages are distinguished for LCA studies (ISO 2006a, 2006b): Goal and scope definition. Inventory analysis. Impact assessment. Interpretation. Among the numerous LCA applications, the following ones are highlighted: Detection of opportunities to improve the environmental performance of products throughout the different stages of their life cycle. Information collection to support decision making within organizations (e.g. strategic planning, prioritization, product/process design or re-design, etc.). Selection of environmental indicators and measurement techniques. Marketing. For instance, by implementing an environmental labelling scheme, making an environmental claim or supporting a product’s environmental statement.
Chapter 2 32 Figure 2.3. LCA framework and applications (adapted from ISO 2006a) The four traditional stages for LCA studies are further explained. Goal and scope definition The goal and the scope of an LCA should be clearly defined and coherent with the application planned. Because of the iterative nature of LCA, the scope could be updated during the study. The goal defines the potential use and audience of the specific LCA case study as well as its justification, while the scope establishes key aspects of the study such as product system, its functions, functional unit (FU), system boundaries, allocation procedures, impact categories, environmental impact assessment method, data requirements, assumptions and restrictions. The FU (ISO 2006a) quantifies the functions of the target product. The main purpose of an FU is to provide a reference to which inputs and outputs are related. An LCA is performed by defining product systems as models which describe the core of the physical systems. System boundaries determine the unit processes to be included within the system. Data quality requirements specify the characteristics of the data needed for the study. Time, geography, technology, accuracy, completeness, consistency, LCA FRAMEWORK Goal and scope definition Inventory analysis Impact assessment Interpretation of results DIRECT APPLICATIONS Product development and improvement Strategic planning Policy making Marketing Labelling Others
Introduction to management tools 33 reproductiveness, data sources and uncertainty are some of the aspects considered in data quality. Inventory analysis The life cycle inventory analysis stage demands an inventory of the input and output data for the system under study. Consequently, this phase involves data collection as well as the explanation of the calculation procedures used. Qualitative and quantitative data are collected for each of the unit processes within the system boundaries. Collected data come from measurement, calculation or estimate, and are used to quantify the inputs and outputs of a unit process. Among the measures to guarantee a proper understanding of the system product, the following ones are underscored: Making process flow diagrams in order to describe all unit processes and their interrelation. Listing the flows and operation data related to every unit process. Listing the units used. Describing the calculation and collection data techniques. In 1991 the Society of Environmental Toxicology and Chemistry (SETAC) proposed a general flow diagram for life cycle inventory (Figure 2.4). This diagram comprises all phases in the life cycle of a process (Fava et al. 1991). Inventory data collection is the most time- and resource-demanding step when an LCA is performed. Collection will be different depending on the specific context. Four groups can be distinguished regarding data acquisition (von Bahr 2001): (i) direct measures, (ii) published documents, (iii) electronic sources, and (iv) personal communications. Among these information sources, commercial databases have been and are still being one of the main tools for finding inventory data (Fullana & Puig 1997). Data for each of the unit processes inside the system boundaries can be classified as: (i) energy inputs, raw materials, auxiliary inputs and other physical inputs, (ii) products, co-products and waste streams, (iii) emissions to air, effluents to water and waste to soil, and (iv) other environmental items.
Chapter 2 34 On the other hand, every calculation procedure should be recorded and the related assumptions should be specified and detailed. The same calculation methods should be used throughout the whole study. Figure 2.4. Flow diagram for life cycle inventory (adapted from Fava et al. 1991) Given the relevance of allocation within this stage, some notations are introduced. In order to make a representative and reproducible system inventory, not only quality data is needed, but also a correct allocation of these data related to each of the subsystems to be evaluated (Feijoo et al. 2007b). A cause-effect relationship is established between raw material consumption/waste generation/system emissions and the activity or process which gives rise to the function being assessed. In the case of systems accounting for only one product (monofunctional processes), allocation is direct. However, problems emerge when dealing with overall input/output data for a system which produces more than one product (multifunctional processes) or functions which influence more than one life cycle (e.g. open-loop recycling) (Feijoo et al. 2005). Multifunctional processes are those processes whose function requires the concurrence of more than one process. They include production processes which Raw material acquisition Manufacture, processing and formulation Transport and distribution Use/Re - use/ Maintenance Recycling Waste management System boundaries Energy INPUTS OUTPUTS Raw materials Technosphere - Products Environment - Emissions - Effluent - Waste
Introduction to management tools 35 give rise to more than one product, as well as waste treatment processes with more than one waste flow or energy generation (Ekvall & Finnveden 2001). In this type of systems, environmental burdens must be distributed among the different products or processes. With this purpose, inputs and outputs are allocated to the different products on the basis of procedures which must be clearly specified. Allocation procedures should capture the main features and relationships regarding inputs and outputs. The addition of the inputs and outputs allocated to a unit process shall equal the addition of the inputs and outputs prior to allocation. Impact assessment The objective of the life cycle impact assessment (LCIA) is to provide further information to evaluate the results of the life cycle inventory in order to better understand the environmental performance of a product system. This stage determines the relevance of the environmental impacts from the results of the previous phase. This step involves the association of inventory data with different environmental impact categories and their corresponding indicators. LCIA includes the compilation of the resulting values for a set of indicators regarding different impact categories which, as a whole, show the LCIA profile for a certain product system. The LCIA results present limitations concerning uncertainty because of the lack of space and time dimensions in the life cycle inventory results. Furthermore, there are no widely accepted methodologies which link inventory data and potential environmental impacts in a consistent and accurate way. Issues such as the selection, modelling and assessment of the impact categories add subjectivity to the LCIA stage. The mandatory items in the LCIA phase comprise: Selection of impact categories, indicators and characterization models. This selection should include an exhaustive set of environmental issues related to the system under study, and should be in agreement with the defined goal and scope. Assignment of life cycle inventory results to the selected impact categories (classification).
Chapter 2 36 Calculation of the values for the category indicators (characterization). Characterization means the conversion of the life cycle inventory results to common units and the addition of the converted results belonging to the same impact category. This conversion uses characterization factors. The calculation output is the quantitative result of an indicator. There are several LCIA options which can also be useful depending on the specific LCA goal and scope. They include: Normalization. It is the calculation of the magnitude of the indicators values related to the reference information. It is aimed to facilitate the understanding of the relative magnitude of each indicator. Weighting. It is the conversion and potential addition of the indicator results through the impact categories by means of numerical factors based on value judgments. Additional data quality analysis (gravity analysis, uncertainty analysis, sensitivity analysis). Finally, it is important to distinguish the two different LCIA methodology groups according to their final objective: Environmental impact assessment methods (mid-point). These methods result in the definition of an environmental profile by means of the quantification of the environmental effect of the product on several categories (acidification, ozone layer depletion, etc.). Contrary to the second group, mid-point methods (also known as distance-to-target methods) evaluate the indirect/intermediate effects on the human being. Damage assessment methods (end-point). These methodologies evaluate the final effect of the environmental impact by identifying and determining the damage caused to the human being ant the natural systems. Because of its use in this dissertation, one of the most common mid-point methods is here presented: the CML method published by the Centre of Environmental Science of the Leiden University (Heijungs et al. 1992). The CML guide (Guinée et al. 2001) provides a list of impact categories grouped in: (i) mandatory categories (categories used in most of the LCA studies), and (ii) other impact categories. Specifically, the mandatory impact categories are: acidification (Edwards & Hutton 1999), ozone layer depletion, abiotic resources depletion,
Introduction to management tools 37 global warming (Nakicenovic et al. 1998), eutrophication, human toxicity, ecotoxicity –fresh water aquatic ecotoxicity, marine aquatic ecotoxicity, terrestrial ecotoxicity– (Huijbregts et al. 2001), and photochemical oxidant formation (UNECE 2003). Interpretation The interpretation of the life cycle results is the final stage of the LCA procedure. In this phase and according to the goal and scope defined for the LCA study, the results from the life cycle inventory analysis and the LCIA are summarized and discussed with the aim of identifying the relevant issues and drawing conclusions, recommendations and information for decision making. 2.3.2. Life Cycle Assessment for seafood The first LCA studies on food were performed at the beginning of the nineties of the twentieth century, and since then, they have been used to answer questions about processing (identification of the most impact-contributing subsystems from an environmental perspective) as well as to compare food products or processes with the same function (Mattson & Sonesson 2003). One of the sectors where LCA has been widely implemented is the agri-food sector, being a common requirement in marketing strategies. However, while LCA in agriculture is quite well established (Andersson 2000), the use of this tool to assess seafood production systems is a more recent phenomenon (Pelletier et al. 2007). To date, the several researchers devoted to LCA of fisheries and aquaculture have evaluated a short number of species. Among the different studies, the following ones are highlighted: Norwegian cod fishing and salmon farming (Ellingsen & Aanondsen 2006). Danish fish products, especially focused on flatfish (Thrane 2006). Frozen fillets from cod fished in the Baltic Sea (Ziegler et al. 2003). Creeling and trawling of Norway lobster caught along the Swedish west coast (Ziegler & Valentinsson 2008). Production of rainbow trout in Finland (Grönroos et al. 2006). Trout farming in France (Papatryphon et al. 2004a, 2004b).
Chapter 2 38 Shrimp aquaculture in Thailand (Mungkung et al. 2006). Carnivorous finfish production (Aubin et al. 2006, 2009): rainbow trout in freshwater raceways in France, sea bass in sea cages in Greece, and turbot in an inland re-circulating system close to the seashore in France. Salmon culture in Canada (Ayer & Tyedmers 2009). Spanish tuna fisheries (Hospido & Tyedmers 2005) and canned tuna manufacture in Spain (Hospido et al. 2006). As a whole, the conclusions drawn from these studies suggest the suitability of LCA to report environmental measures in both fishing and aquaculture. Specifically, the studies treating fisheries tend to identify the capture phase as the most contributing stage, mainly due to diesel demand. On the other hand, aquaculture studies usually stress the relevance of the farming stage because of the role played by feed and energy use. Although there is a growing interest in the use of LCA methodology to improve the sustainability performance of seafood production and consumption systems, further efforts are needed (Pelletier et al. 2007; Ayer et al. 2009). This doctoral thesis contributes to widen the range of species studied under an LCA approach. Furthermore, this dissertation develops new trends in LCA of seafood such as the combined use of Data Envelopment Analysis (DEA) plus LCA, or the implementation of Carbon Footprinting (CF) schemes. 2.4. Carbon Footprinting The increasing awareness of climate change as a global concern has led stakeholders to demand a standard procedure to measure and communicate greenhouse gas (GHG) emissions linked to consumer products. In this context, Carbon Footprinting (CF) has raised as an environmental tool not only for companies along the product chain but also for policy makers (Iribarren et al. 2010). Carbon Footprinting (CF) involves the estimate of the overall amount of GHG emissions associated with a product (i.e., any good or service) along its supply chain, even including use and end-of-life recovery and disposal (EPLCA 2007). According to Carbon Trust et al. (2008), “the term ‘product carbon footprint’
Introduction to management tools 39 refers to the GHG emissions of a product across its life cycle, from raw materials through production (or service provision), distribution, consumer use and disposal/recycling. It includes the greenhouse gases carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O), together with families of gases including hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs)”. Contrary to popular belief, CF is not a new topic. In fact, product carbon footprint is quantified using life cycle impact indicators for the global warming mid-point category. Hence, the carbon footprint could be understood just as a subset of the data covered by a more complete LCA. However, the use of carbon footprints for communication purposes questions the aptitude of the existing ISO standards to address the environmental impacts due to GHG emissions from products in a consistent and comprehensive way (SETAC 2008). Standardization efforts could be necessary to provide guidance for people interested in quantifying the carbon footprint of a product. Within this framework, several initiatives have arisen to meet the increasing market demand for climate relevant information along supply chains (Finkbeiner 2009). This tool is further explained in Chapter 10, where the assessment of carbon footprints is discussed for the case of a common canned mussel product (Iribarren et al. 2010). 2.5. Data Envelopment Analysis Data Envelopment Analysis (DEA) is a performance measurement methodology used to empirically quantify the comparative productive efficiency of multiple similar entities (Cooper et al. 2007). To carry out a DEA (Figure 2.5), data for inputs and outputs from the different entities must be known. From these data, DEA formulates and solves an optimization model which facilitates benchmarking the operational performance of each assessed entity. This benchmarking provides a basis for decreases in inputs per unit of output, usually resulting in an improved eco-efficiency. In this sense, DEA enables the discrimination of inefficient operating points, therefore promoting feasible technological improvements under the perspective of an efficient operational performance.
Chapter 2 46 Lozano, S., Iribarren, D., Moreira, M.T., Feijoo, G. (2010). “Environmental impact efficiency in mussel cultivation”. Resour Conserv Recy. DOI: 10.1016/j.resconrec.2010.04.004 Mattsson, B., Sonesson, U. (2003). “Environmentally-friendly food processing”. Woodhead Publishing Limited, Cambridge, England Mungkung, R.T., Udo de Haes, H.A., Clift, R. (2006). “Potentials and limitations of Life Cycle Assessment in setting ecolabelling criteria: A case study of Thai shrimp aquaculture product”. Int J Life Cycle Ass 11 (1), 55-59 Nakicenovic, N., Victor, N., Morita, T. (1998). “Emissions scenarios database and review of scenarios”. Mitigation and Adaptation Strategies for Global Change 3 (2-4), 95-120 Papatryphon, E., Petit, J., van der Werf, H.M.G., Kaushik, S. (2004a). “Life Cycle Assessment of trout farming in France: A farm level approach”. In: Halberg, N. (ed.), 2004. “Life Cycle Assessment in the agri-food sector. Proceedings from the 4 th International Conference”, October 5-8, 2003, Bygholm, Denmark. Danish Institute of Agricultural Sciences. Dias Report 61, 71-77 Papatryphon, E., Petit, J., Kaushik, S., van der Werf, H.M.G. (2004b). “Environmental impact assessment of salmonid feeds using Life Cycle Assessment (LCA)”. Ambio 33 (6), 316-323 Pelletier, N.L., Ayer, N.W., Tyedmers, P.H., Kruse, S.A., Flysjo, A., Robillard, G., Ziegler F., Scholz, A.J., Sonesson, U. (2007). “Impact categories for Life Cycle Assessment research of seafood production systems: Review and prospectus”. Int J Life Cycle Ass 12 (6), 414-421 SETAC Europe LCA Steering Committee (2008). “Standardisation Efforts to Measure Greenhouse Gases and 'Carbon Footprinting' for Products”. Int J Life Cycle Ass 13 (2), 87-88 Thrane, M. (2006). “LCA of Danish fish products”. Int J Life Cycle Ass 11 (1), 66-74 UNECE (2003). “Air pollution studies nº 15. Guidelines for estimating and reporting emission data under the convention on long-range transboundary air pollution”. United Nations, Geneva, Switzerland UNEP (2007). “Life Cycle Management – A business guide to sustainability”. Nairobi: United Nations Environment Programme. ISBN 978-92-807-2772-2 United Nations (1987). “Report of the World Commission on Environment and Development”. General Assembly Resolution 42/187, 11 December 1987 Vázquez-Rowe, I., Iribarren, D., Moreira, M.T., Feijoo, G. (2010). “Combined application of Life Cycle Assessment and Data Envelopment Analysis as a
Introduction to management tools 47 methodological approach for the assessment of fisheries”. Int J Life Cycle Ass 15 (3), 272-283 von Bahr, B. (2001). “The relevance aspect of Life Cycle Inventory Data Quality”. Doctoral Thesis. Department of Environmental Systems Analysis, Chalmers University of Technology, Gothenburg, Sweden Ziegler, F., Nilsson, P., Mattsson, B., Walther, Y. (2003). “Life Cycle Assessment of frozen cod fillets including fishery-specific environmental impacts”. Int J Life Cycle Ass 8 (1), 39-47 Ziegler, F., Valentinsson, D. (2008). “Environmental life cycle assessment of Norway lobster (6ephrops norvegicus) caught along the Swedish west coast by creels and conventional trawls – LCA methodology with case study”. Int J Life Cycle Ass 13, 487-497
SECTIO II. APPLICATIO OF LIFE CYCLE ASSESSMET I EXTESIVE AQUACULTURE. THE MUSSEL SECTOR
Life Cycle Assessment of the mussel culture 51 Chapter 3 Life Cycle Assessment of mussel culture 1 Summary The LCA of the mussel sector begins with Chapter 3, which deals with the culture phase. With this purpose, the main mussel production areas in Galicia were investigated. Inventory data came from interviews and surveys from a set of vessels accounting for the production of more than 7,000 tonnes of mussels cultured in rafts. In addition, physicochemical characterization of wastewater from the boats was performed. Abiotic resources depletion, global warming, ecotoxicity, human toxicity, acidification, ozone layer depletion, photochemical oxidant formation and eutrophication were the impact categories evaluated. Characterization results for each of the categories revealed the importance of taking into account not only the operational issues, but also capital goods. Diesel use for the boat was found as the main contributor to potential environmental impacts, along with electricity and iron production linked to capital goods. Furthermore, an analysis with four different scenarios was carried out, highlighting the importance of studying capital goods in greater detail. Another analysis was performed to prove the lack of consensus when characterizing toxicity and ecotoxicity potentials. Finally, mussel aquaculture was compared to mussel capture, finding that mussel aquaculture may present a higher potential environmental impact for farmed mussels due to a greater consumption of diesel and to the involvement of a number of operational inputs and outputs without correspondence in current data for mussel capture. 1 Iribarren, D., Moreira, M.T., Feijoo, G. (2010). “Life Cycle Assessment of mussel culture”. In: “Mussels: Anatomy, Habitat and Environmental Impact”, Nova Science Publishers, New York, USA (in press)
Chapter 3 52 Index 3.1. Introduction .................................................................................................... 53 3.2. Methods ......................................................................................................... 54 3.2.1. System boundaries .................................................................................. 54 3.2.2. Functional unit ........................................................................................ 56 3.2.3. Data acquisition ...................................................................................... 56 3.2.4. Life cycle inventory ................................................................................ 58 3.3. Results ............................................................................................................ 63 3.4. Discussion and identification of improvement potentials .............................. 67 3.4.1. Toxicity and ecotoxicity potentials ......................................................... 67 3.4.2. Eutrophication potential .......................................................................... 68 3.4.3. Improvement potentials .......................................................................... 69 3.4.4. Electricity demand for capital goods ...................................................... 70 3.4.5. Mussel capture ........................................................................................ 72 3.5. Conclusions, recommendations and perspectives .......................................... 73 3.6. References ...................................................................................................... 74
Life Cycle Assessment of the mussel culture 53 3.1. Introduction The expansion and intensification of aquaculture has raised a number of issues in terms of its negative impact on the environment. As previously mentioned in Chapter 1, mussels are the single largest cultured shellfish in Galicia (more than 200,000 tonnes per year), with a relevant impact on its economy (turnover of roughly 100,000,000 €) (Xunta de Galicia 2006). Galician cold waters and the regional geographic nature with characteristic rias provide fabulous aquaculture areas for farming mussels in floating structures called rafts. Considering the great importance of the Galician mussel sector, this activity was considered for the evaluation of its environmental performance by LCA. Figure 3.1. The Spanish mussel sector. Dashed lines mean that the main inputs for systems S6 and S7 come from the mussel processing systems The Spanish mussel sector is divided into ten systems as shown in Figure 3.1: Mussel aquaculture in rafts (S1). Mussel purification in dispatch centres for the fresh-consumption market (S2). Mussel processing in canning factories to produce canned mussels (S3). S1. MUSSEL CULTURE S2. MUSSEL PURIFICATION S3. CANNING INDUSTRY S8. FRESH MUSSEL CONSUMPTION S9. CANNED MUSSEL CONSUMPTION S6. MUSSEL SHELL MANAGEMENT S7. MUSSEL ORGANIC WASTE MANAGEMENT S4. BOILING/ FREEZING INDUSTRY S5. CANNING INDUSTRY ALTERNATIVE S10. FROZEN MUSSEL CONSUMPTION
Chapter 3 54 Mussel processing in cooking plants to produce either frozen (S4) or canned mussels (S4 and further processing in S5). Final consumption of fresh (S8), canned (S9) and frozen (S10) mussels. Valorization of mussel shell and debris from processing factories to produce calcium carbonate (S6). Treatment of the mussel organic remains from processing plants (S7). This chapter is focused on the evaluation of the environmental impacts associated with mussel culture in traditional rafts in Galicia. 3.2. Methods The main objective of this chapter is to evaluate the potential environmental impacts linked to mussel (Mytilus galloprovincialis) aquaculture. To achieve this goal, inventory data from interviews and surveys from a representative sample of 22 vessels accounting for the production of more than 7,000 tonnes of farmed mussels were collected. The identification of the activities with a significant environmental impact will make it possible to propose a framework for alternatives which leads to a better environmental performance. 3.2.1. System boundaries Figure 3.2 presents a diagram of the system under study (S1). All the activities performed in the raft were included, from seed collection to the packaging prior to the dispatch of the cultured mussels. Furthermore, construction, operation and maintenance of the raft as well as of the auxiliary cultivation boats were also considered. The term auxiliary boat is used to distinguish boats used for aquaculture purposes from regular fishing vessels. Figure 3.2. System under study: mussel culture (S1) Construction, operation and maintenance of the raft Construction, operation and maintenance of the auxiliary boat Seed collection Prefattening Rope thinning Harvesting Selection Previous packaging
Life Cycle Assessment of the mussel culture 55 The system boundaries for the LCA of mussel cultivation included all the abovementioned activities as a whole, then demanding one thorough inventory. Figure 3.3 shows the process flow diagram for mussel culture. Figure 3.3. Process flow diagram for mussel aquaculture CONSTRUCTION OF THE RAFT AND COMPONENTS CONSTRUCTION OF THE BOAT AND COMPONENTS Inputs: energy demand (electricity), flax, cotton, nylon, HDPE, PET, concrete, wood, iron Inputs: energy demand (electricity), polypropylene, wood, stainless steel, steel, iron Treatment of end - of - use materials Other outputs: waste to treatment (end-of-use materials from capital goods) Raft and components Boat and components C U L T I V A T I O N SEED COLLEC TION PRE - FATTENING ROPE THINNING HARVESTING SELECTION PREVIOUS PACKAGING Main output: mussels of commercial size (product) Outputs: emissions to the sea (nylon, wastewater from the boat), emissions to the atmosphere (from the combustion of diesel) RECYCLING POLYPROPYLENE RECYCLING POLYETHYLENE DISPOSAL OF TEXTILES Waste to treatment: cotton, nylon Waste to treatment: polyethylene Waste to treatment: polypropylene SYSTEM BOUNDARIES Input for the maintenance of the raft: tar oil Inputs for the maintenance of the boat: oil, antifouling paint Input for the operation of the boat: diesel
Chapter 3 62 from nature corresponds to mussel seeds, which are obtained from coastal rocky areas where mussel farmers collect the seeds by means of scrapers (Cáceres- Martínez et al. 1994), and also from collector ropes and netting strips (Tirado & Macias 2006). The other main inputs gathered in the inventory table come from the technosphere, emphasizing the input of Diesel B for use in the auxiliary boat, whose value is in agreement with bibliographic sources (Troell et al. 2004). Another important input to consider is the amount of wood required, which is also in line with other data published elsewhere (García et al. 2000). Table 3.4. Life cycle inventory for mussel culture in traditional rafts IPUTS From the technosphere From the environment Materials and fuels Raw materials 1. Chemicals and other materials 1. Seeds from rocky shoreline Iron 13.03 g Mussel seed 5.85 g Antifouling paint 0.17 g Use of rocky shoreline 5.16·10 -8 ha Stainless steel 0.08 g 2. Seeds from collector ropes Other steels 0.19 g Mussel seed 9.05 g Nylon 3.55 g 3. Seeds from netting strips HDPE 0.32 g Mussel seed 1.81 g PET 0.02 g Total mussel seed 16.71 g Concrete 10.81 g 4. Use of sea surface 59.56 cm 2 Cotton 0.27 g Acetate rayon 9.47 mg Flax 6.69 mg Polypropylene (PP) 0.33 mg Tar oil 1.22 ml Oil C 15 -C 50 0.27 ml 2. Wood Pine and oak 1.84 g Eucalyptus 36.87 g Ash tree 0.01 mg Total Wood 38.71 g 3. Diesel B 15.96 ml Energy 1. Infrastructure and equipments 2.67 MJ
Life Cycle Assessment of the mussel culture 63 Table 3.4. Life cycle inventory for mussel culture in traditional rafts (cont.) OUTPUTS To the technosphere To the environment: emissions to the ocean Final products and intermediate products 1. Wastewater from auxiliary boats 1. Mussel of commercial size 1.00 kg Total COD 0.37 mg O 2 2. Mussel seed (intermediate product) 16.71 g BOD 5 0.02 mg O 2 Waste to treatment Dissolved solids 25.11 mg 1. Polypropylene (PP) 15.24 g Suspended solids 0.12 mg 2. HDPE 0.04 g Chloride 19.94 mg 3. Cotton 0.06 g TOC 0.03 mg C 4. Nylon 0.64 g Chlorine 4.18 mg To the environment: emissions to air Bromine 0.04 mg 1. Carbon dioxide 43.10 g Potassium 0.17 mg 2. Methane 3.99 mg Calcium 0.11 mg 3. Dinitrogen monoxide 1.09 mg Organic nitrogen 3.34 µg N 4. Sulphur dioxide 39.91 mg Fats 0.55 µg 5. Carbon monoxide 100.58 mg Rubidium 0.45 µg 6. Nitrogen oxides 766.30 mg Strontium 4.45 µg 7. NMVOC 31.93 mg Iron 5.57 µg Chrysene 0.01 ng Phenanthrene 0.01 ng Fluoranthene 0.01 ng 2. Nylon 0.12 g 3.3. Results SimaPro 7 was the software used for the computational implementation of the inventory (Goedkoop et al. 2008). The ecoinvent database was chosen for background processes (Frischknecht et al. 2007a), while bibliographic data were used to make the inventory of flax yarn production (Turunen & van der Werf 2006). Classification and characterization following ISO guidelines were performed to assess the potential environmental impact of inputs and outputs from the LCI (ISO 2006). An attributional LCA for mussel culture was made using the CML mid-point method, which results in the definition of an environmental profile for the assessed product by means of the quantification of the environmental effect on different categories. The following impact categories were considered: acidification potential (AP), ozone layer depletion potential (ODP), abiotic depletion potential (ADP), global warming potential (GWP), eutrophication potential (EP), photochemical oxidant formation potential (POFP),
Chapter 3 64 fresh water aquatic ecotoxicity potential (FETP), marine aquatic ecotoxicity potential (METP), terrestrial ecotoxicity potential (TETP), and human toxicity potential (HTP). This set of categories is common in LCA for seafood (Pelletier et al. 2007). When assessing the potential environmental impacts of myticulture, it is advisable to distinguish contributions linked to operation from those related to capital goods (Frischknecht et al. 2007b). Taking this into account, Table 3.5 shows the characterization results for mussel culture. Table 3.5. Environmental characterization for mussel culture in traditional rafts using CML 2 baseline 2000 method Impact category Unit Value Capital goods Operation Total Abiotic depletion kg Sb eq 28.67 27.37 56.03 Global warming kg CO 2 eq 35,862.85 2,553.03 38,415.88 Ozone layer depletion kg CFC-11 eq 0.0017 0.0062 0.0079 Human toxicity kg 1,4-DB eq 11,786.38 1,646.11 13,432.49 Fresh water aquatic ecotoxicity kg 1,4-DB eq 3,761.44 116.90 3,878.34 Marine aquatic ecotoxicity kg 1,4-DB eq 49,951,170.96 533,774.13 50,484,945.09 Terrestrial ecotoxicity kg 1,4-DB eq 81.45 -2.69 78.76 Photochemical oxidant formation kg C 2 H 2 eq 21.38 0.13 21.50 Acidification kg SO 2 eq 563.65 20.76 584.41 Eutrophication kg PO 4 3- eq 24.46 7.85 32.30 The term capital goods involves the consumption of energy, iron, concrete, textile materials, plastics, steel and wood for the construction of machinery and equipment used in mussel farming, but cutting off the treatment of these materials after their use. On the other hand, the term operation stands for (i) diesel use for the operation of the boat, (ii) the use of oil and antifouling paint for the maintenance of the boat, (iii) tar oil use for the maintenance of the raft, (iv) treatment of solid wastes from operation, and (v) wastewater from boats. This latter was considered the only direct emission to the sea, and its analytical study provided real (nonestimated) values for the associated pollution. No estimates concerning other
Life Cycle Assessment of the mussel culture 65 emissions to the sea were included, meaning that the release of non-ferrous metals related to the use of antifouling paint was excluded on the rationale of a lack of agreement between toxicity factors and the state of the oceans, which are deficient in this type of metals (Hospido 2005). With regard to operation in mussel aquaculture, it should be emphasized that there is neither electricity consumption nor refrigeration involved within this operational chain. Figure 3.6 clearly shows the contribution of operation and capital goods to the environmental impact categories, demonstrating the importance of considering capital goods as an impact source within mussel aquaculture. The extensive and non-continental nature of mussel farming in Spain put forward this result as known for agricultural products according to the recommendations of Frischknecht et al. (2007b). -5% 10% 25% 40% 55% 70% 85% 100% ADP GWP ODP HTP FETP METP TETP POFP AP EP Capital goods Operation Figure 3.6. Contribution of operation and capital goods to the potential environmental impacts linked to mussel culture As shown in Figure 3.6, capital goods established themselves as the main origin of the potential environmental impacts related to the following categories: AP, EP, POFP, GWP, HTP and the three ecotoxicity categories (FETP, METP and TETP). Regarding ADP, a similar contribution for both operation and capital goods was observed. However, the main contribution to ODP came from operation,
Chapter 3 66 which accounted for roughly 80% of the total potential impact for this category, while the remaining 20% was linked to capital goods. Once the potential contribution of capital goods and operational issues was compared for the different categories, the next step consisted of the identification of the main processes contributing to potential environmental impacts in mussel culture. This step determines the usefulness of LCA as a decision supporting tool, and its results are summarized in Figure 3.7, where the potential contributions to each of the impact categories are shown for the six processes identified as the main contributors. 0 20 40 60 80 100 120 ADP GWP ODP HTP FETP METP TETP POFP AP EP Contribution (%) Cotton production (capital goods) Nylon production (capital goods) Iron production (capital goods) Electricity production (capital goods) Diesel consumption (operation) Paint consumption (operation) Figure 3.7. Process contribution for mussel farming in rafts As captured in Figure 3.7, three processes stood out as the main sources of the potential environmental impacts: electricity production for capital goods, diesel use in boat operation and, to a lesser extent, iron use for capital goods. Electricity production corresponds to the electricity production mix for Spain. This process prevailed for GWP (contribution of more than 90% to the potential impact for this category), POFP (91%), AP (92%), and EP (57%), as well as for the four toxicity and ecotoxicity categories (71% for HTP, 87% for FETP, 95% for METP, and 89% for TETP). Moreover, electricity production for capital goods accounted for 14% of the potential impact for ODP.
Life Cycle Assessment of the mussel culture 67 Diesel use included diesel production as well as its combustion for boat operation. This process arose as the main potential source of impact for ADP (potential contribution of 49% to this impact category) and ODP (78%). It also entailed a relevant contribution to the potential environmental impact for EP (29%), GWP (12%) and TETP (8%). Iron use for capital goods also played a role in the environmental characterization of mussel farming. This is mainly due to the large weight of floats and shackle chains for rafts even though their lifetimes have been taken into account. Thus, this process significantly contributed to ADP with a percentage of 48% of the impact for this category, also involving lower percentages for GWP (6%), ODP (6%) and POFP (5%). Furthermore, toxicity and ecotoxicity categories were also affected by this process (15% for HTP, 9% for FETP, 3% for METP and 10% for TETP). To a lesser extent, other processes contributed to the potential environmental impacts. For example, nylon production (mainly related to the use of ropes for mussel farming) accounted for a contribution of 9% to EP, 6% to GWP, and 2% to POFP, AP and TETP. Other examples are paint production for the maintenance of the boat (contribution of 7% to HTP and 5% to TETP) or cotton production (contribution of 8% to EP and 2% to ADP). 3.4. Discussion and identification of improvement potentials 3.4.1. Toxicity and ecotoxicity potentials The toxicity and ecotoxicity values obtained from characterization strongly depend on the selected method (Renou et al. 2008). In order to study this dependence, the EDIP 2003 method was used, obtaining new values to characterize toxicity and ecotoxicity potentials. Thus, Table 3.6 compares these values with those corresponding to CML 2000. The following conclusions were drawn: The lump sum of the values for the three EDIP 2003 categories linked to human toxicity accounted for 97.93% of the total toxicity impact; whereas, if CML 2000 is used, then the value for the human toxicity potential only involved 0.03% of the total toxicity impact.
Chapter 3 68 If EDIP 2003 is used, the sum of the values for the two different categories related to water ecotoxicity accounted for only 2.06% of the total toxicity impact; while the value of the sum of the two CML 2000 categories associated with water ecotoxicity meant 99.97%. Finally, the value for soil (terrestrial) ecotoxicity potential accounted for 1.66·10 -3 % of the total toxicity impact when using EDIP 2003 and, similarly, for 1.46·10 -4 % if CML 2000 is used. According to the two first conclusions, a lack of consensus was proved when characterizing toxicity and ecotoxicity potentials. Nevertheless, both methods led to the same main contributor: electricity production to satisfy the energy demand for capital goods. Table 3.6. Toxicity and ecotoxicity comparison using two different methods CML 2 baseline 2000 HTP FETP METP TETP (kg 1,4-DB eq) 13,432.49 3,878.34 50,484,945.08 78.76 EDIP 2003 V1.01 ETWC ETWA ETSC HTA HTW HTS (m 3 ) 6,430,372.11 2,341,658.90 7,069.15 415,816,565.28 320,533.93 3,610.16 ETWC: ecotoxicity water chronic ETWA: ecotoxicity water acute ETSC: ecotoxicity soil chronic HTA: human toxicity air HTW: human toxicity water HTS: human toxicity soil 3.4.2. Eutrophication potential When studying mussel farming, EP also becomes a controversial impact category. In this respect, it has been suggested that mussels (filter feeders) can act as a buffer against eutrophication processes since they mean a top down control on the phytoplankton biomass and sequester nutrients, which would be removed if mussels were harvested (Nakamura & Kerciku 2000; Cloern 2001). However, Nizzoli et al. (2005) estimated the global effects of suspended mussel (Mytilus galloprovincialis) farming on oxygen and nutrient dynamics. This study found ratios between particulate nutrient consumption and net dissolved nutrient regeneration rates of 1.1 for nitrogen and 2.5 for phosphorous. Nevertheless, their
Life Cycle Assessment of the mussel culture 69 results question the belief that dense populations of mussels act as a buffer against eutrophication problems since, whilst it was true that the mussel ropes exerted an intense grazing pressure on the phytoplankton, the ingested organic nutrients were rapidly recycled back to the water column by the mussel ropes and the underlying sediments, where they would stimulate further phytoplankton growth. Thus, the net effect of mussels may be to increase phytoplankton turnover and productivity, rather than to decrease phytoplankton biomass. Consequently, in this LCA of mussel farming, it was decided not to perform any correction factor regarding the characterization value for EP, which would lead to an EP value lower than that gathered in Table 3.5. 3.4.3. Improvement potentials Characterization results are very useful when approaching improvement actions in the myticulture field. In this sense, LCA for mussel culture led to focus the identification of improvement potentials not only on operational issues but also on capital goods. However, specific improvement actions on capital goods are difficult to identify because of the prevalence of electricity production as the main contributor to the different impact categories. Related to energy consumption, mussel cultivation is not considered to be an activity with high energy consumption as compared to the cultivation of other species such as shrimp or salmon (Troell et al. 2004), especially regarding operational activities. Nonetheless, according to the previous results, it seems evident that improvement actions concerning operation should be centred on the minimization of diesel consumption in the auxiliary boat, which would lead to a significant improvement for the environmental indicators studied. Efforts should be made with the objective of reducing the diesel demand for operation in auxiliary boats: use of fuels with higher energy efficiency, sustainable planning and logistic organization of boat route up to the rafts, etc. Regarding capital goods, it would be advisable to act on the corresponding energy demands. However, the estimated term energy demand for capital goods involves all the capital goods for mussel farming and then actions on this term become difficult. On the contrary, this obstacle is not found when dealing with the minimization of iron consumption, since improvement potentials affect a limited set of capital goods: engines, floats, chains and shackles. For these improvement
Chapter 3 70 purposes, there is a wide range of alternatives including technological innovation (such as the use of new materials). 3.4.4. Electricity demand for capital goods According to the environmental characterization results, electricity production for capital goods was found as one of the main contributors to the different impact categories. However, the value of the electricity demand for capital goods means a rough estimate and it should be more accurate, which could be achieved by inventorying in greater detail the different capital goods involved in mussel culture. Since this possibility is out of the scope of this dissertation, an additional analysis was carried out according to four different scenarios with the aim of assessing the relevance associated with the uncertainty in the value of the electricity demand: Scenario 0: case study (no action). Scenario 1: reduction of 10% for the overall energy (electricity) demand for capital goods. Scenario 2: reduction of 25%. Scenario 3: reduction of 50%. Figure 3.8 shows that as the overall energy demand for capital goods was decreased, a gradual reduction in characterization values was observed. This reduction was clear for GWP, AP, METP, HTP, TETP, POFP, FETP and EP. On the other hand, there was no influence over ADP, and the influence was minimal for ODP. These observations stress the importance of studying capital goods in greater detail. The performance of further analyses involving scenarios with different models for electricity production was not considered necessary, since the electricity production mix for Spain is assumed to be the most accurate approach. In fact, the uncertainty is primarily focused on the value itself, not on the electricity mix.
Life Cycle Assessment of the mussel culture 71 0 100 200 300 400 500 600 ADP TETP POFP AP EP Corresponding Units Scenario 0 Scenario 1 Scenario 2 Scenario 3 0 10000 20000 30000 40000 GWP HTP FETP Corresponding Units Scenario 0 Scenario 1 Scenario 2 Scenario 3 0E+00 2E-03 4E-03 6E-03 8E-03 ODP kg CFC-11 eq Scenario 0 Scenario 1 Scenario 2 Scenario 3 0 10 20 30 40 50 METP kt 1,4-DB eq Scenario 0 Scenario 1 Scenario 2 Scenario 3 Figure 3.8. Analysis for the relevance of the energy value used in capital goods , , , ,
Chapter 4 78 Index 4.1. Introduction .................................................................................................... 79 4.2. Methods ......................................................................................................... 80 4.2.1. System boundaries .................................................................................. 81 4.2.2. Functional unit ........................................................................................ 85 4.2.3. Data acquisition ...................................................................................... 86 4.2.4. Life cycle inventory ................................................................................ 88 4.3. Results .......................................................................................................... 100 4.3.1. Fresh mussels from dispatch centres .................................................... 100 4.3.2. Canned mussels from canning factories ............................................... 102 4.3.3. Frozen mussels from cooking plants .................................................... 105 4.4. Discussion and identification of improvement potentials ............................ 106 4.4.1. Mussel processing and consumption .................................................... 106 4.4.2. Whole mussel sector ............................................................................. 109 4.4.3. Environmental comparison among mussel-based products .................. 111 4.5. Conclusions, recommendations and perspectives ........................................ 113 4.6. References .................................................................................................... 113
Life Cycle Assessment of mussel-based products 79 4.1. Introduction Mussels are becoming a very popular food within the current society. China, Thailand and Spain are the most important mussel producing countries (Conde 2007). Actually, if only mussels for human consumption are taken into account, the Spanish production is even more relevant. As known, in Spain, mussels (Mytilus Galloprovincialis) are mainly cultured in Galicia, where the extensive aquaculture comprises not only farming, but also several processing activities, including mussel purification in dispatch centres, mussel cooking, mussel freezing and mussel canning. From a regional point of view, this network of activities leads to a key economic sector. Therefore, apart from mussel culture, the Galician mussel sector includes other activities (Franco 2006) which are performed by different economic actors depending on the processing alternative selected for mussel transformation. Thus, three main sub-sectors can be assumed according to the centres where the transformation takes place: (i) dispatch centres sub-sector (fresh mussel market), (ii) canning factories sub-sector, and (iii) mussel cooking plants sub-sector. In Chapter 3, the mussel farming sub-sector was studied from an LCA perspective, whereas Chapter 4 assesses mussel transformation in dispatch centres, canning factories and mussel cooking plants, as well as mussel consumption in households. In this sense, the LCA of mussels from a sectorial perspective is presented together with the environmental comparison of three different mussel products: fresh mussels, frozen boiled mussels and canned mussels. The use of LCA is justified because of its proved ability to provide the seafood industry with production chain transparency and accountability (Iles 2007). In fact, LCA results mean a powerful tool for companies and governments in order to facilitate decision and policy making. Hence, the application of this life cycle approach to the mussel sector seeks sustainability in the production and consumption of this seafood (Ayer et al. 2009). Beyond the regional and national relevance of this comprehensive case study, the expected results could be useful for countries with an emerging market for mussels such as China or Chile.
Chapter 4 80 4.2. Methods The goal of this chapter is to environmentally assess mussel processing and consumption, as well as the mussel sector as a whole. Mussel processing is directed at the manufacture of the three main mussel products: fresh, canned and frozen mussels. These products present a common origin –mussels cultured in rafts–, but then these farmed mussels are diverted to different mussel sub-sectors. One possibility for cultured mussels is their purification in dispatch centres in order to reach markets as fresh mussels for human consumption. A second alternative would be to send farmed mussels to canning factories where they are processed to obtain the canned product. Finally, the third option involves the processing of mussels in cooking plants. The boiled mussels can be further processed to obtain frozen mussels in the same plant or they can be canned in partial canning factories. The difference between canning factories and partial canning factories lies in that the latter receive mussel meat which has been previously boiled in mussel cooking plants so, unlike canning factories –which directly process farmed mussels–, these partial facilities omit mussel washing, de-clumping, trimming, cooking and dehydrating operations. In particular, the goal of this chapter comprises the performance of three environmental assessments in order to analyze the impact potentials linked to the following systems: Fresh mussel consumption, including a previous stage for mussel purification (culture stage excluded). Canned mussel consumption, which previously involves mussel transformation in canning factories (culture stage and mussel shell treatment excluded). Frozen mussel consumption, involving mussel transformation in cooking plants prior to consumption (culture stage excluded together with mussel shell treatment). Additionally, these assessments will lead to an environmental comparison among fresh, canned and frozen mussels, as well as to the LCA of the whole mussel sector. Note that, as reflected in Figure 3.1 (Chapter 3), the whole mussel sector demands the consideration of those systems regarding specific mussel waste treatment (S6 and S7). In this chapter, the implementation of these
Life Cycle Assessment of mussel-based products 81 treatment systems will be directly done when presenting the LCA of the whole sector and the comparative LCA (Iribarren et al. 2010). Nonetheless, Chapter 5 will provide detailed information concerning mussel waste treatment from an LCA perspective. 4.2.1. System boundaries Fresh mussels from dispatch centres The study of mussel purification (S2) implies the evaluation of a dispatch centre for molluscs. A dispatch centre is any on-shore or off-shore establishment for the reception, conditioning, washing, cleaning, grading, wrapping and packaging of fresh molluscs for human consumption. This centre is provided with the equipment required to remove pathogens potentially present in molluscs before their consumption as a fresh product. To make the inventory of system S2, the following operations were considered: mussel haulage, seawater reception, seawater sterilization by chlorine gas dosage, mussel self-purification in pools, seawater discharge (carrying out a control of pathogens in the outlet stream of the pools), and product haulage. Consequently, the following processes were included within the boundaries of S2: production of chlorine gas, electricity and polypropylene (for containers); water discharge; initial and final haulage; and management of organic waste set aside for the production of fish meal and fish oil. On the other hand, the consumption stage for fresh mussels (S8) took into account: cooking of fresh mussels (equivalent electricity consumption), shopping travel, production of plastic bags and special meshes and labels for fresh mussels, and waste treatment. Processes inside the system boundaries of S8 included: production of polyethylene (HDPE and LDPE), tap water production, electricity production, transport for shopping, wastewater treatment, and management of municipal solid waste. Canned mussels from canning factories The study of mussel transformation in canning factories (S3) was performed according to the different stages shown in Figure 4.1 (Xunta de Galicia 2005).
Chapter 4 82 Figure 4.1. Mussel transformation in canning factories FINAL OPERATIONS PROCESSING Cooking Mussel flesh separation Byssus removal Size grading Dehydrating Checking Packaging Liquid dosage and filling Sealing Washing Sterilization Washing and drying Codification Cartoning and packaging Storage INITIAL OPERATIONS Mussel reception Washing and sieving De-clumping and washing Trimming Storage Storage Cleaning Formulation Can reception Ingredient reception ANCILLARY OPERATIONS Boilers and heating General cleaning Machinery maintenance Wastewater treatment Bathroom fittings
Life Cycle Assessment of mussel-based products 83 For the environmental analysis of system S3, six subsystems were defined (Figure 4.2): Subsystem SS3.1 considers mussel haulage from cultivation sites up to the target canning factory. Thus, transport was the only process within the boundaries of this subsystem. Subsystem SS3.2 comprises the initial operations carried out in the canning factory: mussel reception, washing and sieving, de-clumping and washing, and trimming. Additionally, other operations such as can reception, storage and cleaning as well as ingredient reception, storage and formulation were considered. Therefore, a wide range of processes were included inside the boundaries of SS3.2: water discharge to the sea, sodium hydroxide production and transport, can production and transport, tap water supply, ingredient production and transport, electricity production, management of mussel organic waste, and waste treatment. Subsystem SS3.3 includes the following processing operations: cooking, mussel flesh separation, byssus removal, size grading, dehydrating, checking, packaging, liquid dosage and filling. Processes considered within the boundaries of SS3.3 were: electricity production, management of mussel organic waste, and waste treatment. Subsystem SS3.4 comprises the final operations performed in the canning factory: sealing, washing, codification, sterilization, washing and drying, cartoning and packaging, and storage. The corresponding processes within the boundaries of this subsystem were: tap water supply, cardboard production and transport, electricity production, and waste treatment. Subsystem SS3.5 includes the ancillary operations: wastewater treatment, bathroom fittings, machinery maintenance, general cleaning, boilers and central heating. A number of processes were included within the boundaries of SS3.5: water discharge and gas emissions; fuel oil production; tap water supply; production and transport of coagulants, flocculants, alkaline cleaner and lubricating oil; electricity production; and waste treatment. Subsystem SS3.6 considers canned mussel transport from the canning factory to retailers. Similarly to SS3.1, transport was the only process in the boundaries of this subsystem.
Chapter 4 84 Figure 4.2. Subsystems for mussel transformation in canning factories (S3) Finally, the consumption stage for canned mussels (S9) took into account: shopping travel, production of plastic bags, and waste treatment. Thus, processes within the system boundaries of S9 were: polyethylene production, transport for shopping, and waste treatment for cardboard, tinplate and municipal solid waste. Mussels from cooking plants Cooking plants are linked to systems S4, S5, S9 and S10. Regarding the system boundaries of this sub-sector, it should be emphasized that system S4 is divided into two subsystems as shown in Figure 4.3. With respect to system S9, it is a system shared with the previous sub-sector of canning factories, while S10 consists of a single inventory for the consumption of frozen mussels. Figure 4.3. Sub-sector of mussel cooking plants (treatment of mussel wastes excluded) As presented in Figure 4.3, system S4 is made up of two subsystems. The first one (SS4.1) covers mussel boiling. Afterwards, the boiled mussel flesh produced in SS4.1 has two main paths. A fraction is destined to frozen mussel production in the cooking plant itself (SS4.2), and the rest is used to produce canned mussels in partial canning factories (S5). SS4.1. Mussel cooking SS4.2. Mussel freezing S10. Frozen mussel consumption S5. Alternative mussel canning S9. Canned mussel consumption SS3.6. Transport canning factoryretail sites SS3.1. Transport cultivation sites-canning factory SS3.2. Initial operations SS3.3. Processing SS3 .4. Final operations SS3.5. Ancillary operations
Life Cycle Assessment of mussel-based products 85 SS4.1 involves the following operations within its boundaries: (i) mussel transport from cultivation sites, (ii) reception, (iii) washing and sieving, (iv) declumping and washing, (v) trimming, (vi) cooking, (vii) mussel flesh separation, (viii) byssus removal, (ix) size grading, (x) dehydrating, and (xi) ancillary operations (wastewater treatment, maintenance, etc.). On the other hand, SS4.2 consists of (i) reception, (ii) cold storage, (iii) processing and packaging, (iv) ancillary operations (cleaning, industrial cold, maintenance, etc.), and (v) transport of frozen boiled mussels to retailers. Partial canning factories (S5) include: (i) mussel boiled flesh transport from cooking plants, (ii) reception, (iii) packaging (canning), (iv) liquid dosage and filling, (v) sealing, washing and codification, (vi) sterilization, (vii) washing and drying, (viii) cartoning and final packaging, (ix) storage, (x) ancillary operations (wastewater treatment, maintenance, etc.), and (xi) canned mussel transport to retailers. 4.2.2. Functional unit Fresh mussels from dispatch centres For the assessment of mussel transformation in dispatch centres (S2) and fresh mussel consumption (S8), the FU was defined as 1 kg of fresh mussels for consumption. Canned mussels from canning factories In the case of the environmental evaluation of mussel transformation in canning factories (S3) and canned mussel consumption (S9), the FU was 1 kg of canned mussel flesh (from S3) for consumption. Frozen mussels from cooking plants For the study of the environmental performance of mussel transformation in cooking plants to produce frozen mussels (SS4.1 and SS4.2), and frozen mussel consumption (S10), the selected FU was 1 kg of frozen-boiled mussel flesh for consumption. Whole mussel sector The accomplishment of a realistic environmental characterization of the whole mussel sector should be based on the commercial behaviour of this sector. Thus,
Chapter 4 86 according to specific bibliography (MAPA 2001; Tirado & Macias 2006; Xunta de Galicia 2006, 2007), the distribution of 100 kg of mussels cultured in rafts is as follows: 40 kg are used to produce fresh mussels in dispatch centres, 35 kg are sent to canning factories, 20 kg are processed for frozen mussel production in cooking-freezing plants, while the remaining 5 kg arrive to mussel cooking plants before being transformed in partial canning factories. The LCA of the whole mussel sector is then performed by taking into account 100 kg of mussels from aquaculture and their conventional market share. Comparison of mussel-based products The environmental comparison among fresh, canned and frozen mussels is established on the basis of the supply of 8.385 g of proteins. This value corresponds to the amount supplied by one standard round can of mussels (43 g of mussel flesh) (Isabel 2009). 4.2.3. Data acquisition Fresh mussels from dispatch centres For mussel purification (S2), data were taken from a dispatch centre where 230 tonnes of purified fresh mussels are annually produced. Moreover, water samples were collected from the input and output streams of the dispatch centre and they were analytically measured. Standard methods (APHA 1995) were used in order to value the main physicochemical parameters: Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD 5 ), Total Solids, Total Volatile Solids, Total Suspended Solids, Total Volatile Suspended Solids, chloride, Total Organic Carbon (TOC), Total Kjeldahl Nitrogen (TKN), fats and oils, etc. In addition, metal content (Ca, Ni, Cu, Zn, Br, Sr) was determined using X-ray fluorescence. Canned mussels from canning factories Data for canned mussel production were gathered in collaboration with a highprofile canning factory which annually produces around 1,180 tonnes of canned mussels (mussel flesh without filling liquid). An exhaustive study of input and output streams was carried out. Furthermore, existing reports were used for the characterization of the corresponding wastewaters (Soto el al. 1990; García-Sandá et al. 2003).
Life Cycle Assessment of mussel-based products 87 Frozen mussels from cooking plants Data for mussel cooking (SS4.1) were derived from partial data available for S3 by ruling out the processes after cooking and dehydrating. On the other hand, data for boiled mussel freezing (SS4.2) were based on the information provided by the environmental statements of four factories whose activity concerns seafood freezing (Congalsa 2006, 2007; Frinova 2006; Mascato 2007). Whole mussel sector The LCA of the whole mussel sector made use of the data acquired for the previous studies. However, supplementary data were needed for the alternative mussel canning (S5). These data were adapted from data for S3 by means of the exclusion of the processes linked to mussel boiling. General considerations and assumptions Electricity production was considered by using the electricity production mix for Spain as presented in the ecoinvent database (Dones et al. 2007). The quantification of capital goods was avoided (Renou et al. 2008) on the basis of the long life estimated for the installations (more than 20 years in every case), also bearing in mind that the entire production of this type of factories is not exclusively mussel-oriented. For example, this mollusc represents 57.5% of the total production in the dispatch centre, and 6.6% in the canning factory. Capital goods were only considered within the mussel culture system (S1). In the individual assessments of fresh, canned and frozen mussels, mussel organic waste from processing facilities was considered a by-product for the production of fish meal and fish oil. Hence, in these assessments, this by-product was regarded as a product avoiding the production of the organic input associated with fish meal production (Nielsen et al. 2003). This means that allocation was avoided by a system expansion assuming that mussel organic waste equals the input of organic matter which is processed in fish meal plants; that is, in the case of fish meal production as reported by Nielsen et al. (2003): 1 kg of mussel organic waste replaces 1 kg of sand eel (but not 1 kg of fish meal). This rough assumption is avoided in the LCA of the whole mussel sector and in the comparative LCA by following the guidelines provided by Iribarren et al. (2010) for the implementation of mussel waste treatment.
Chapter 4 94 Table 4.3e. Inventory data for mussel transformation in canning factories: SS3.5 (cont.) OUTPUTS To the technosphere To the environment Product Emissions to the ocean (13.50 dm 3 ) 1. Thermal energy 2.98 MJ 1. Fats 0.02 g Waste to treatment (authorized agent) 2. BOD 5 0.18 g O 2 1. Stainless metallic waste 0.03 g 3. Total COD 1.28 g O 2 2. Iron metallic waste 0.20 g 4. Suspended solids 0.65 g 3. Water from bathroom fittings 3.28 cm 3 5. Total phosphorus 2.61 mg 4. Sludge and fats from wastewater treatment 17.77 g 6. Ammoniacal nitrogen 0.12 g 5. Lubricant oils 0.08 g Emissions to the atmosphere 6. Lead batteries 2.43·10 -8 units 1. CO 2 409.23 g 7. Dry batteries 2.43·10 -6 units 2. SO 2 0.47 g 8. Electronic equipment 1.21·10 -8 units 3. COV 1.12 mg 9. Fluorescent tubes 9.72·10 -7 units 4. NO x 0.13 g 5. CO 0.03 g Table 4.3f. Inventory data for mussel transformation in canning factories: SS3.6 IPUTS OUTPUTS From the technosphere To the technosphere Transport Product 1. Canned mussels up to retail sites 0.10 km 1. Dispatched and canned mussel flesh 1.00 kg Material 1. Canned mussel flesh 1.00 kg Table 4.4. Inventory data for the consumption of canned mussels from S3 IPUTS FROM THE TECHOSPHERE Materials 1. Dispatched and canned mussel flesh 1.00 kg 2. Plastic bags (LDPE) 3.80 g Transport 1. Shopping travel 0.05 m
Life Cycle Assessment of mussel-based products 95 Table 4.4. Inventory data for the consumption of canned mussels from S3 (cont.) OUTPUTS TO THE TECHOSPHERE Waste to treatment 1. Cans (tinplate) to recycling 333.87 g 2. Cans (tinplate) to landfill 191.08 g 3. Carton to recycling 51.22 g 4. Carton to landfill 31.13 g 5. Municipal solid waste: plastic bags 3.80 g Frozen mussels from cooking plants Table 4.5a-b gathers the inventories for the subsystems involved in frozen mussel production. On the other hand, Table 4.6 shows the inventory for the consumption of frozen mussels in households. Table 4.5a. Inventory data for frozen mussel production: SS4.1 IPUTS From the technosphere From the environment Materials and fuels Matter 1. Chemicals and other materials 1. Water Alkaline cleaner 0.61 g Seawater 3.89 dm 3 Aluminium polychloride 0.14 cm 3 Surface Anionic gel 2.14 mm 3 1. Land occupation 0.12 dm 2 Soda 1.17 g Lubricant oil 0.01 g 2. Raw materials Mussels of commercial size 12.67 kg 3. Fresh water 5.69 dm 3 4. Fuel oil 0.03 kg Energy 1. Electric energy 0.43 kWh 2. Thermal energy 1.19 MJ Transport 1. Mussels up to the factory 0.80 t·km 2. Soda 3.42·10 -4 t·km 3. Flocculant 1.05·10 -6 t·km 4. Coagulant 8.97·10 -5 t·km 5. Lubricant oil 3.42·10 -7 t·km 6. Alkaline cleaner 3.73·10 -5 t·km
Chapter 4 96 Table 4.5a. Inventory data for frozen mussel production: SS4.1 (cont.) OUTPUTS To the technosphere To the environment Product Emissions to the atmosphere 1. Boiled mussel flesh 1.00 kg 1. CO 2 164.43 g By-products 2. SO 2 0.19 g 1. Mussel shell 2.38 kg 3. VOC 0.45 mg 2. Mussel debris 1.90 kg 4. NO x 0.05 g 3. Mussel organic waste 0.34 kg 5. CO 0.01 g Intermediate product Emissions to the ocean 1. Thermal energy 1.19 MJ 1. Fats 0.01 g Waste to treatment (authorized agent) 2. BOD 5 0.12 g O 2 1. Stainless metallic waste 0.17 g 3. COD 3.68 g O 2 2. Iron metallic waste 1.16 g 4. Suspended solids 4.29 g 3. Water from racking systems cleaning 1.96 g 5. Total phosphorus 1.66 mg 4. Water from bathroom fittings 1.62 cm 3 6. Ammoniacal nitrogen 0.08 g 5. Lead batteries 1.39·10 -7 units 7. Chloride 0.08 kg 6. Sludge and fats from wastewater treatment 11.32 g 7. Lubricant oils 0.03 g 8. Fluorescent tubes 5.55·10 -6 units 9. Dry batteries 1.39·10 -5 units 10. Electronic equipments 6.39·10 -8 units Table 4.5b. Inventory data for frozen mussel production: SS4.2 IPUTS Materials and fuels from the technosphere Energy from the technosphere 1. Raw material 1. Electric energy 0.40 kWh Boiled mussel flesh 1.00 kg 2. Thermal energy 0.42 MJ 2. Fresh water 2.75 dm 3 Transport 3. Containers 1. Frozen mussel flesh up to the retail site 0.65 t·km Paperboard 50.27 g 2. Plastics 0.13·10 -2 t·km PET 0.20 g 3. Paperboard 0.60·10 -2 t·km LDPE 0.32 g From the environment: surface HDPE 1.73 g 1. Land occupation 0.08 dm 2 Other plastics 8.44 g
Life Cycle Assessment of mussel-based products 97 Table 4.5b. Inventory data for frozen mussel production: SS4.2 (cont.) OUTPUTS To the technosphere To the environment Final product Emissions to the ocean (2.38 dm 3 ) 1. Dispatched frozen-boiled mussel flesh 1.00 kg 1. Suspended solids 0.29 g Waste to treatment 2. COD 1.46 g O 2 1. Plastic waste 1.33 g 3. BOD 5 0.86 g O 2 2. Paperboard waste 1.33 g 4. Fats 0.05 g 3. Wood waste 0.43 g 5. Detergents 0.10·10 -2 g 4. Sludge from wastewater treatment 27.94 g 6. Ammonium 0.56·10 -2 g 5. Scrap 0.24 g 7. Total phosphorus 0.43·10 -2 g 6. Hazardous waste: mineral oil 0.07 g 7. Hazardous waste: material contaminated with hydrocarbon compounds 0.03·10 -2 g 8. Hazardous waste: batteries 0.01·10 -2 g 9. Hazardous waste: fluorescent tubes 0.12·10 -2 g 10. Hazardous waste: used solvent 0.89·10 -2 g 11. Hazardous waste: containers and absorbents 4.62·10 -2 g Table 4.6. Inventory data for frozen mussel consumption IPUTS FROM THE TECHOSPHERE Materials 1. Dispatched frozen-boiled mussel flesh from SS4.2 1.00 kg 2. Plastic bags (LDPE) 3.80 g Transport 1. Shopping travel 0.14 m OUTPUTS TO THE TECHOSPHERE Waste to treatment 1. Plastic to recycling 2.41 g 2. Plastic to landfill 9.07 g 3. Carton to recycling 36.90 g 4. Carton to landfill 17.13 g 5. Municipal solid waste: plastic bags 3.80 g
Chapter 4 98 Additional information for the whole mussel sector To perform the LCA of the whole mussel sector, the inventory for canned mussel production in partial canning factories was needed. Table 4.7 presents this inventory. Table 4.7. Inventory data for canned mussel production in partial canning factories (S5) IPUTS From the technosphere From the environment Materials and fuels Matter 1. Chemicals and other materials 1. Water Alkaline cleaner 0.62 g Seawater 3.11 dm 3 Aluminium polychloride 0.08 cm 3 Surface Anionic gel 1.22 mm 3 1. Land occupation 0.12 dm 2 Empty cans (tinplate) 0.66 kg Lubricant oil 0.02 g 2. Raw materials Boiled mussel flesh 1.34 kg Oils 0.25 kg 3. Water Fresh water 8.70 dm 3 4. Cardboard 0.10 kg 5. Fuel Fuel oil 0.04 kg Energy 1. Electric energy 0.93 kWh 2. Thermal energy 1.79 MJ Transport 1. Boiled mussel flesh up to the factory 0.10 t·km 2. Canned mussels up to the retail site 0.10 km 3. Ingredients 2.52·10 -4 t·km 4. Containers 0.78 t·km 5. Cardboard 0.01 t·km 6. Flocculant 5.99·10 -7 t·km 7. Coagulant 5.12·10 -5 t·km 8. Lubricant oil 5.14·10 -7 t·km 9. Alkaline cleaner 3.80·10 -5 t·km
Life Cycle Assessment of mussel-based products 99 Table 4.7. Inventory data for canned mussel production in partial canning factories (S5) (cont.) OUTPUTS To the technosphere To the environment Final product Emissions to the atmosphere 1. Dispatched and canned mussel flesh 1.00 kg 1. CO 2 245.80 g By-product 2. SO 2 0.28 g 1. Mussel organic waste 0.34 kg 3. VOC 0.67 mg Intermediate product 4. NO x 0.08 g 1. Thermal energy 1.79 MJ 5. CO 0.02 g Waste to treatment (authorized agent) Emissions to the ocean 1. Stainless metallic waste 0.17 g 1. Fats 0.85·10 -2 g 2. Iron metallic waste 1.19 g 2. BOD 5 0.07 g O 2 3. Defective cans (tinplate) 3.08 g 3. COD 2.10 g O 2 4. Water from bathroom fittings 1.65 cm 3 4. Suspended solids 2.45 g 5. Paper and cardboard 22.38 g 5. Total phosphorus 0.95 mg 6. Plastics 7.83 g 6. Ammoniacal nitrogen 0.04 g 7. Lead batteries 1.41·10 -7 units 7. Chloride 0.05 kg 8. Sludge and fats from wastewater treatment 6.46 g 9. Lubricant oils 0.05 g 10. Fluorescent tubes 5.65·10 -6 units 11. Dry batteries 1.41·10 -5 units 12. Electronic equipment 7.06·10 -8 units 13. Ink cartridges 7.27·10 -6 units Finally, it should be noted that the study of the whole mussel sector considers that 12.50% of the consumed canned mussels comes from partial factories (Tirado & Macias 2006; Xunta de Galicia 2007). In this sense, when characterizing the whole sector, the inventory for system S9 is just as that in Table 4.4 but, instead of assuming 1.00 kg of canned mussels from S3, the following origin should be specified: 0.875 kg from S3 and 0.125 kg from S5.
Chapter 4 100 4.3. Results As in the previous chapter, SimaPro 7 was the software used for the computational implementation of the different inventories (Goedkoop et al. 2008). The ecoinvent database was also chosen for background processes, just resorting to other databases when necessary, specifically for oil as an ingredient in the production of canned mussels (data adapted from LCA Food data base) and cans for the canning factory (BUWAL 250). Classification and characterization following ISO guidelines were applied to analyze the potential environmental impact of inputs and outputs from the LCIs. This set of LCAs was performed using the CML method. AP, ODP, ADP, GWP, EP, POFP, FETP, METP, TETP and HTP were the impact categories assessed. 4.3.1. Fresh mussels from dispatch centres The characterization results for mussel purification (S2) and fresh mussel consumption (S8) were studied together. Figure 4.4 clearly illustrates the contribution of fresh mussel purification and consumption to the selected impact categories. A much greater relevance of system S2 for each of the impact categories is observed, which included a positive potential impact for ADP due to the consideration of mussel organic waste as a by-product for the production of fish meal and fish oil. Note that mussel culture stage (S1) was omitted from this analysis. Furthermore, LCA characterization results led to the identification of the main processes contributing to undesirable environmental impacts linked to fresh mussels. These processes are summarized in Figure 4.5. ADP is not represented in this figure since a desirable potential impact was found because of the consideration of mussel organic waste as a by-product avoiding the input associated with fish meal production (Nielsen et al. 2003); this fact captured the total contribution to ADP.
Life Cycle Assessment of mussel-based products 101 -100% -80% -60% -40% -20% 0% 20% 40% 60% 80% 100% ADP GWP ODP HTP FETP METP TETP POFP AP EP Purification and haulage Consumption Figure 4.4. Contributions to the environmental impact potentials: S2 and S8 0 20 40 60 80 100 GWP ODP HTP FETP METP TETP POFP AP EP Contribution (%) Water discharge (purification) Chlorine gas production (purification) Final haulage (purification) Electricity (purification) Electricity (consumption) Municipal solid waste management (consumption) Figure 4.5. Process contribution for fresh mussels As observed in Figure 4.5, electricity use in mussel purification stood out as the main source of potential impact. This process prevailed for GWP (contribution of more than 90% to the potential impact for this category), ODP (52%), POFP (95%), AP (95%), HTP (84%), FETP (77%) and TETP (79%).
Chapter 4 102 Moreover, electricity production for mussel purification accounted for 16% of the potential impact for METP and for 4% of the potential impact for EP. On the other hand, water discharge to the sea in the dispatch centre was found to be the main contributor to two impact categories: EP (95% of the total impact for this category) and METP (84%). To a lesser extent, other processes contributed to the potential environmental impacts. For example, chlorine gas production accounted for a contribution of 36% to ODP, 11% to TETP, and 1% to HTP. Other examples are final haulage from the dispatch centre (contribution of 6% to GWP, 12% to ODP, 3% to POFP, 2% to AP, 3% to HTP and 4% to TETP), management of municipal solid waste from household consumption (contribution of 20% to FETP and 1% to HTP), electricity use for fresh mussel consumption (contribution of 1% to GWP, POFP, AP, HTP, FETP and TETP) or polypropylene production for containers (contribution of 2% TETP). 4.3.2. Canned mussels from canning factories The characterization results for mussel transformation in canning factories (S3) and canned mussel consumption (S9) were also analyzed. Figure 4.6 illustrates the contribution of S3 and S9 to the impact categories. The contribution related to system S3 was analyzed distinguishing initial haulage, initial operations, processing, final operations, ancillary operations and final haulage. A much greater relevance of system S3 for every impact category was concluded as compared to household consumption of canned mussels, whose major potential contributions were around 10% for both FETP and TETP. The culture stage (S1) was omitted from this analysis, as well as the treatment of mussel shells from canning factories. According to Figure 4.6, initial operations subsystem (SS3.2) prevailed for ADP, GWP, POFP, AP and EP, while ancillary operations subsystem (SS3.5) did for ODP and TETP. With regard to HTP, FETP and METP, impact contribution was found to be mainly shared by initial operations (SS3.2), processing (SS3.3) and final operations (SS3.4). The processing subsystem (SS3.3) showed a desirable potential impact on ADP and ODP due to the consideration of mussel organic waste as a by-product avoiding the input associated with fish meal production. Finally, haulage contributions to the potential environmental impacts
Life Cycle Assessment of mussel-based products 103 were not as noticeable as those related to other subsystems; initial haulage (SS3.1) was found to contribute more than final haulage (SS3.6). -10% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% ADP GWP ODP HTP FETP METP TETP POFP AP EP Initial haulage Initial operations Processing Final operations Ancillary operations Final haulage Consumption Figure 4.6. Contributions to the environmental impact potentials: S3 (subsystems) and S9 The summary of the main processes which contributed to the potential environmental impacts linked to canned mussels from canning factories is presented in Table 4.8. From this summary, it is observed that the origin of ADP was mainly related to three processes: can production (SS3.2), oil production (SS3.2) and fuel oil production (SS3.5). Oil production was also found as the major contributor to GWP; other processes with a significant contribution to this impact category were the production and transport of cans (SS3.2), gas release in SS3.5, and electricity production for SS3.2, SS3.3 and SS3.4. Fuel oil production was identified as the main process contributing to ODP. Oil production also showed a relevant contribution to this impact category. For the four toxicity and eco-toxicity impact categories, it was shown that the three electricity production processes linked to final operations, processing and initial operations were the key contributors. Another process with a relevant contribution to these impact categories was can transport. Regarding TETP, it
Chapter 4 110 management of 8.44 kg of mussel shell, and the treatment of 0.76 kg of mussel organic waste. -20% 0% 20% 40% 60% 80% 100% ADP GWP ODP HTP FETP METP TETP POFP AP EP Culture sub-sector Fresh mussel sub-sector Whole canning factories sub-sector Cooking plants sub-sector Figure 4.9. Contributions to the potential environmental impact by the different mussel sub-sectors Except for ODP, Figure 4.9 reveals that the sub-sector linked to fresh mussels (dispatch centres) prevailed for all impact categories, especially for METP and EP. For ODP, culture was the sub-sector with the greatest contribution. In fact, mussel farming sub-sector was the second main contributor to the rest of categories. With regard to the sub-sectors of mussel cooking plants and canning factories, their contribution was much lower than that of the other two subsectors. This observation is closely related to the high level of optimization for the operations performed in cooking and canning facilities, especially when compared to the unsustainable operation in dispatch centres (traditional family business). Furthermore, the potentially favourable environmental contributions (desirable effects) observed for AP and EP in the case of the cooking and canning sub-sectors are due to the assumption of avoided burdens regarding mussel pâté production (mussel organic waste treatment). The environmental characterization for the mussel sector led to the conclusion that fresh mussels are the most critical branch within this sector because of the outdated operation performance in dispatch centres. Specifically, the hot spot where improvement actions should be performed is the electricity consumption.
Life Cycle Assessment of mussel-based products 111 As stated above, new electrical systems with frequency inverters should be adopted. It could be thought that the environmental relevance of the fresh mussel subsector is due to the fact that 40% of the mussels from aquaculture are sent to dispatch centres. In this sense, the following comparative LCA for mussel products helps to refute this idea. 4.4.3. Environmental comparison among mussel-based products A comparative LCA was carried out in order to compare fresh, canned and frozen mussels on the basis of an equitable functional unit. With this purpose, Table 4.9 compares the characterization values for the potential environmental impacts associated with these three mussel products by taking as functional unit the same protein supply: 8.385 g. This value corresponds to the amount of proteins supplied by either the consumption of one can of mussels (43.00 g of mussel flesh) (Isabel 2009) or the consumption of 322.50 g of fresh mussels (shell and water also included in this final weight) (Consello Regulador 2009) or the consumption of 49.09 g of frozen mussel flesh (Paquito 2009). In Table 4.9, the term fresh mussels (FM) involved the joint consideration of culture, purification (mussel organic waste management included) and household consumption, whereas the term canned mussels (CM) included cultivation, mussel transformation in canning factories (87.50% processed in whole canning factories and 12.50% in partial ones; treatment of mussel shell and organic waste included) and household consumption. Finally, the term frozen-boiled mussels (FBM) embraced farming, mussel transformation in cooking-freezing facilities (management of mussel shell and organic waste included) and household consumption. From the ratios FBM/CM gathered in Table 4.9, a similar environmental performance is reported for canned and frozen mussels. On the other hand, the highest potential environmental impact is noted for fresh mussels since all impact categories presented a greater characterization value than those corresponding to canned and frozen mussels. From inventory data, 322.50 g of fresh mussels imply the farming of 393 g of mussels, while 43.00 g of canned mussel flesh involve the cultivation of 545 g of mussels; and 49.09 g of frozen mussel flesh mean the culture of 622 g of mussels. Moreover, it has been proved that household consumption has little influence on
Chapter 4 112 the potential environmental impact. Therefore, the higher potential environmental impact for fresh mussels is linked to mussel purification but not to mussel culture or consumption. Table 4.9. Environmental comparison among mussel products on the basis of an equal supply of proteins Fresh mussels (FM) Canned mussels (CM) Frozen-boiled mussels (FBM) Ratio FBM/CM Ratio FM/FBM ADP (kg Sb eq) 0.85·10 -2 0.37·10 -2 0.39·10 -2 1.05 2.19 GWP (kg CO 2 eq) 1.12 0.42 0.47 1.10 2.40 ODP (kg CFC-11 eq) 1.09·10 -7 7.05·10 -8 7.62·10 -8 1.08 1.44 HTP (kg 1,4-DB eq) 0.24 0.11 0.13 1.15 1.88 FETP (kg 1,4-DB eq) 8.77·10 -2 2.97·10 -2 3.49·10 -2 1.17 2.51 METP (kg 1,4-DB eq) 5,886.57 79.92 86.81 1.09 67.81 TETP (kg 1,4-DB eq) 0.25·10 -2 0.17·10 -2 0.19·10 -2 1.12 1.30 POFP (kg C 2 H 4 eq) 0.04·10 -2 0.02·10 -2 0.02·10 -2 1.00 2.07 AP (kg SO 2 eq) 1.02·10 -2 0.21·10 -2 0.29·10 -2 1.40 3.51 EP (kg PO 4 3- eq) 1.00·10 -2 -0.01·10 -2 -3.04·10 -5 0.24 -328.94 Where the FU chosen for this comparative study was 1 kg of dry edible mussel flesh, then similar conclusions would be drawn. In such case, the highest potential environmental impact would also be for fresh mussels given that all impact categories would present a greater characterization value than those for canned and frozen mussels, apart from TETP and ODP.
Life Cycle Assessment of mussel-based products 113 4.5. Conclusions, recommendations and perspectives LCA has been proved to be suitable when pursuing transparency and accountability all along the trade chain for mussels. Inventories were made for fresh/canned/frozen mussel processing and consumption. These inventories complement that one for mussel culture presented in the previous chapter. Moreover, the identification of hot spots allowed the proposal of several improvement potentials concerning each of the mussel products. The need to minimize electricity use in dispatch centres is especially highlighted. The installation of modern electric systems provided with frequency inverters is highly encouraged within these facilities. Additional improvement actions should also affect mussel farming. Furthermore, the LCA of the whole mussel sector revealed that fresh mussel sub-sector was the most contributing one when capturing the real market scenario for mussels. On the contrary, the sub-sectors of mussel cooking plants and canning factories were proved to have a lower contribution to the potential environmental impacts compared to the contribution of culture and dispatch centres sub-sectors. Finally, a comparison among fresh, canned and frozen mussels was performed, and based on the supply of an identical amount of proteins. Consequently, fresh mussels were found to be the mussel product with the least favourable environmental profile. This higher potential environmental impact is closely related to mussel purification. 4.6. References APHA-AWWA-WPCF (1995). “Standard Methods for the examination of water and wastewater”. 19 th ed. Washington, United States Ayer, N.W., Côté, R.P., Tyedmers, P.H., Willison, J.H.M. (2009). “Sustainability of seafood production and consumption: an introduction to the special issue”. J Clean Prod 17, 321-324 Barros, M.C., Magán, A., Valiño, S., Bello, P.M., Casares, J.J., Blanco, J.M. (2009). “Identification of best available techniques in the seafood industry: a case study”. J Clean Prod 17, 391-399 Conde, A. (2007). “The Spanish mussel sector”. <www.havbrukskompaniet.no>
Chapter 4 114 Congalsa (2006). “Declaración Medioambiental Año 2006 – Empresa: Congalsa” (in Spanish). Riveira, Spain Congalsa (2007). “Declaración Medioambiental Año 2007 – Empresa: Congalsa” (in Spanish). Pobra do Caramiñal, Spain Consello Regulador Mexillón de Galicia (2009). <www.mexillondegalicia.org> Dones, R., Bauer, C., Bolliger, R., Burger, B., Faist Emmenegger, M., Frischknecht, R., Heck, T., Jungbluth, J., Röder, A., Tuchschmid, M. (2007). “Life Cycle Inventories of Energy Systems: Results for Current Systems in Switzerland and other UCTE Countries”. ecoinvent report No. 5, v2.0, Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland Franco, M. (2006). “A miticultura en Galicia: unha actividade de éxito e con futuro” (in Galician). Revista Galega de Economía 15 (1), 251-256 Frinova (2006). “Frinova – Declaración Ambiental 2005” (in Spanish). Porriño, Spain García-Sandá, S., Omil, F., Lema, J.M. (2003). “Clean production in fish canning industries: recovery and reuse of selected wastes”. Clean Techn Environ Policy 5, 289-294 Goedkoop, M., de Schryver, A., Oele, M. (2008). “Introduction to LCA with SimaPro 7”. PRé Consultants, the Netherlands Hospido, A., Vázquez, M.E., Cuevas, A., Feijoo, G., Moreira, M.T. (2006). “Environmental assessment of canned tuna manufacture with a life-cycle perspective”. Resour Conserv Recy 47, 56-72 Iles, A. (2007). “Making the seafood industry more sustainable: creating production chain transparency and accountability”. J Clean Prod 15, 577-589 Illescas, J.L., Bacho, O., Ferrer, S. (2007). “Evolución y tendencias en los mercados de moluscos” (in Spanish). Distribución y consumo, 34-40 Iribarren, D., Moreira, M.T., Feijoo, G. (2010). “Implementing by-product management into the Life Cycle Assessment of the mussel sector”. Resour Conserv Recy. DOI: 10.1016/j.resconrec.2010.03.017 Isabel - Conservas Garavilla (2009). <www.isabel.net> MAPA (2001). “Libro Blanco de la Acuicultura” (in Spanish). Ministry of Agriculture, Fisheries and Food, Spain Mascato (2007). “Declaración Ambiental Mascato Salvaterra s.l. Año 2007” (in Spanish). Salvaterra de Miño, Spain Nielsen, P.H., Nielsen, A.M., Weidema, B.P., Dalgaard, R., Halberg, N. (2003). “LCA food data base”. <www.lcafood.dk>
Life Cycle Assessment of mussel-based products 115 Paquito (2009). <www.sabordemar.com> Renou, S., Thomas, J.S., Aoustin, E., Pons, M.N. (2008). “Influence of impact assessment methods in wastewater treatment LCA”. J Clean Prod 16, 1098- 1105 Sim, S., Barry, M., Clift, R., Cowell, S.J. (2007). “The relative importance of transport in determining an appropriate sustainability strategy for food sourcing. A case study of fresh produce supply chains”. Int J Life Cycle Ass 12 (6), 422-431 Soto, M., Méndez, R., Lema, J.M. (1990). “Efluentes residuales en la industria de procesado de productos marinos” (in Spanish). Ingeniería Química (June 1990), 203-209 Thrane, M. (2006). “LCA of Danish fish products”. Int J Life Cycle Ass 11 (1), 66-74 Tirado, C., Macias, J.C. (2006). “Cultivo de mejillón. Aspectos generales y experiencias en Andalucía” (in Spanish). Regional Ministry of Agriculture and Fisheries, Andalucia, Spain Xunta de Galicia (2005). “Autorización Ambiental Integrada - Guía de aplicación nas instalacións destinadas á conserva de peixes e mariscos, 2005” (in Galician). Regional Ministry of the Environment, Galicia, Spain Xunta de Galicia (2006). “Anuario de Pesca Galicia 2005” (in Galician). Regional Ministry of Fisheries and Sea Affairs, Galicia, Spain Xunta de Galicia (2007). “Anuario de Pesca, 2006” (in Galician). Regional Ministry of Fisheries and Sea Affairs, Galicia, Spain
Environmental assessment of mussel waste valorization 117 Chapter 5 Environmental assessment of mussel waste valorization 1 Summary The evaluation of the treatment of specific mussel wastes is a relevant issue when pursuing a comprehensive study of the mussel sector. In this sense, LCA methodology was used in order to characterize (i) mussel shell valorization to produce calcium carbonate, and (ii) mussel organic waste valorization to produce pâté. In the first case, propane and electricity use, sludge and ash management, haulage and atmospheric releases were identified as the hot spots on which the improvement potentials should be focused. Furthermore, the environmental assessment of a future scenario for this valorization process is included. On the other hand, the environmental characterization of mussel organic waste valorization led to the recommendation of acting on the formulation of mussel pâté, the thermal energy demand and the product transport. Finally, the role of these treatment alternatives when implemented into the case study of mussels is discussed. Mussel waste management was found to contribute to the potential environmental impacts to a lesser extent than mussel culture and processing. 1 Iribarren, D., Moreira, M.T., Feijoo, G. (2010). “Implementing by-product management into the Life Cycle Assessment of the mussel sector”. Resour Conserv Recy. DOI: 10.1016/j.resconrec.2010.03.017
Chapter 5 118 Index 5.1. Introduction .................................................................................................. 119 5.2. Methods ....................................................................................................... 119 5.2.1. System boundaries ................................................................................ 120 5.2.2. Functional unit ...................................................................................... 123 5.2.3. Data acquisition .................................................................................... 123 5.2.4. Life cycle inventory .............................................................................. 125 5.3. Results .......................................................................................................... 129 5.3.1. Mussel shell valorization ...................................................................... 129 5.3.2. Mussel organic waste valorization ........................................................ 132 5.4. Discussion and identification of improvement potentials ............................ 134 5.4.1. Mussel shell management ..................................................................... 134 5.4.2. Mussel organic waste management ...................................................... 139 5.4.3. Implementation into the mussel case study .......................................... 141 5.5. Conclusions, recommendations and perspectives ........................................ 142 5.6. References .................................................................................................... 143
Environmental assessment of mussel waste valorization 119 5.1. Introduction The Galician mussel sector does not focus only on cultivation, but also comprises other activities such as those performed by dispatch centres, cooking plants and canning factories (Franco 2006). All these processing activities generate several waste streams which have to be managed. In this context, the management of two specific mussel waste materials should be highlighted: Management of mussel shells and other mussel debris mainly from canning factories and, to a lesser extent, from cooking plants and dispatch centres. The most popular management option for these waste materials is their valorization to obtain calcium carbonate (Barros et al. 2009a). Management of mussel organic waste from canning factories, cooking plants and dispatch centres. This type of waste can be sent to factories that produce fish meal. However, the production of mussel pâté from mussel organic waste is currently a valorization alternative gaining increasing popularity. In this chapter, LCA is used to assess the environmental performance of these management options. This study meets the need for the implementation of the management of mussel shell and organic wastes from processing factories into the target life cycle of the mussel case study. 5.2. Methods The goal of this chapter is to perform a detailed environmental assessment of the waste management systems S6 (i.e., mussel shell management) and S7 (i.e., mussel organic waste management) by means of LCA methodology. Remember that nomenclature is in accordance with Figure 3.1 in Chapter 3. First, the LCA for mussel shell management is posed. The term shell stands for both the mussel shell itself and other valorizable mussel debris. Mussel shell comes mainly from system S3 (canning factories), and is valorized to obtain CaCO 3 . The aim is to environmentally assess this valorization process by characterizing system S6, identifying the corresponding hot spots and proposing several improvement potentials. Second, the LCA for mussel organic waste management is tackled. Mussel organic waste refers to small mussel meat remains which are discarded in the
Chapter 5 126 exhaustive study led to partial inventories for the five subsystems defined for mussel shell valorization. These inventories are presented in Table 5.2a-e. Table 5.2a. Inventory data for mussel shell valorization: SS6.1 IPUTS OUTPUTS From the technosphere To the technosphere Transport Product 1. Shell up to the factory 216.33 km 1. Transported mussel shell and debris 100.00 t Material 1. Mussel shell 55.56 t 2. Mussel debris 44.44 t Table 5.2b. Inventory data for mussel shell valorization: SS6.2 IPUTS OUTPUTS From the technosphere To the technosphere Materials Product 1. Chemicals and other materials 1. Washed and dripped shell 95.00 t Coagulant 55.00 l Waste to treatment DAF flocculant 6.00 kg 1. Sludge 2.50 t Flocculant 7.50 l To the environment 2. Raw materials Emissions to the ocean Transported mussel and debris 100.00 t 1. COD 8.81 kg O 2 3. Water 2. BOD 5 0.19 kg O 2 Fresh water 60.00 m 3 3. Suspended solids 1.56 kg Energy 4. Organic nitrogen 0.46 kg 1. Electric energy 5,100.00 kWh 5. Ammoniacal nitrogen 0.05 kg 6. Fats 0.62 kg 7. Phosphates 0.06 kg 8. Nitrates 0.26 kg
Environmental assessment of mussel waste valorization 127 Table 5.2c. Inventory data for mussel shell valorization: SS6.3 Table 5.2d. Inventory data for mussel shell valorization: SS6.4 IPUTS OUTPUTS From the technosphere To the technosphere Materials Product 1. Chemicals and other materials 1. Calcined shell 60.00 t Propane 2.10 t Waste to treatment Antifouling 0.70 l 1. Ashes 2.00 t Biocide 0.70 l To the environment 2. Raw materials Emissions to the atmosphere Washed and dripped shell 95.00 t 1. Water 35.00 t 3. Water 2. Air 135,520.00 m 3 Cooling water 35.00 m 3 3. NH 3 0.22 kg Energy 4. Particles 0.65 kg 1. Electric energy 5,300.00 kWh 5. SO 2 3.01 kg 6. NO x 32.28 kg NO 2 7. CO 2 6,020.00 m 3 8. O 2 35,905.00 m 3 9. CO 21.95 kg IPUTS OUTPUTS From the technosphere To the technosphere Materials Products 1. Chemicals and other materials 1. Middle CaCO 3 3.00 t Diesel oil 57.00 l 2. Fine CaCO 3 10.00 t Polypropylene big-bags 17.00 units 3. Micronized CaCO 3 24.00 t 2. Raw materials 4. CaCO 3 + sawdust 28.00 t Calcined shell 60.00 t Sawdust 5.00 t Energy 1. Electric energy 5,700.00 kWh
Chapter 5 128 Table 5.2e. Inventory data for mussel shell valorization: SS6.5 IPUTS OUTPUTS From the technosphere To the technosphere Transport Product 1. Products up to destination 299.67 km 1. Transported CaCO 3 100.00 t Material 1. Middle CaCO 3 3.00 t 2. Fine CaCO 3 10.00 t 3. Micronized CaCO 3 24.00 t 4. CaCO 3 + sawdust 28.00 t Mussel organic waste valorization Inventory data for mussel meat waste valorization were obtained from the thorough analysis of a Galician factory which produces pâté. Table 5.3 presents the inventory for S7. Table 5.3. Inventory data for mussel organic waste valorization IPUTS FROM THE TECHOSPHERE Materials Materials 1. Raw materials 4. Containers Mussel organic waste a 100.00 t Cans (tinplate) 91.34 t Water 111.83 t Cardboard 15.13 t Oil 23.61 t Film (LDPE) 2.28 t Egg albumen 6.94 t Energy Skimmed milk powder 5.56 t 1. Electric energy 60,147.60 kWh Starch 2.78 t 2. Thermal energy 850,458.29 MJ Salt 2.78 t Transport Soya protein 2.78 t 1. Mussel organic waste 10,820.00 t·km Aromas and spices 15.28 t 2. Other raw materials 78,624.32 t·km 2. Chemicals and other materials 3. Cans 107,913.84 t·km Flocculant 6.00 kg 4. Cardboard 1,701.26 t·km Coagulant 3.05 kg 5. Film 270.99 t·km 3. Fresh water 1,886.03 m 3 6. Flocculant 2.78 t·km 7. Coagulant 1.30 t·km 8. Product (mussel pâté) 180,063.48 t·km a 44% of the mussel organic waste enters the process as a boiled input, and 56% enters as a nonboiled input. Specifically, 44.12 boiled tonnes come from canning factories, 44.12 non-boiled tonnes come from canning factories, and 11.76 non-boiled tonnes arrive from dispatch centres
Environmental assessment of mussel waste valorization 129 Table 5.3. Inventory data for mussel organic waste valorization (cont.) OUTPUTS To the technosphere To the environment Product Emissions to the ocean 1. Mussel pâté 277.79 t 1. Treated wastewater 1,312.56 m 3 Waste to treatment COD 170.63 kg O 2 1. Cardboard to recycling 0.81 t Nitrates 0.66 kg 2. Film to recycling 0.48 t Emissions to the atmosphere 3. Residual cans (tinplate) 0.43 t 1. CO 2 306.87 kg 4. Sludge 0.40 t 2. CH 4 590.13 kg 3. CO 1.89 kg 4. N 2 28.33 kg 5. H 2 14.16 kg 6. H 2 S 2.83 kg 5.3. Results As in the previous chapters, SimaPro 7 was the software used for the computational implementation of the inventories (Goedkoop et al. 2008). The ecoinvent database was chosen for background processes, just resorting to ETH ESU 96 database (e.g. for the landfill management of the sludge from SS6.2 and S7, or for the consideration of sawdust as wood waste in forest for SS6.4), BUWAL 250 database (e.g. for cans in S7) and LCA Food data base (e.g. data adapted for milk powder in S7) when necessary. Classification and characterization following ISO guidelines were performed to evaluate the potential environmental impact of inputs and outputs from the LCIs. The CML method was used. AP, ODP, ADP, GWP, EP, POFP, FETP, METP, TETP and HTP were the impact categories evaluated. 5.3.1. Mussel shell valorization The characterization results for mussel shell valorization (S6) are presented in Figure 5.3, which clearly illustrates the contribution of the five subsystems to the ten impact categories. Shell haulage (SS6.1) showed contributions ranging from 1% to 7%, whereas the corresponding contribution ranges for initial operations (SS6.2), processing (SS6.3), final operations (SS6.4) and products haulage (SS6.5) were 12-89%, 5- 73%, 2-37% and 2-17%, respectively.
Chapter 5 130 0% 20% 40% 60% 80% 100% ADP GWP ODP HTP FETP METP TETP POFP AP EP SS6.1. Shell haulage SS6.2. Initial operations SS6.3. Processing SS6.4. Final operations SS6.5. Product haulage Figure 5.3. Subsystem contribution to the environmental impact potentials for mussel shell valorization (S6) Furthermore, the following processes were broken down for mussel shell valorization: initial haulage of mussel shell and debris for SS6.1; water supply for SS6.2 and SS6.3; coagulant and flocculant production for SS6.2; electricity production for SS6.2, SS6.3 and SS6.4; sludge management within initial operations (SS6.2); water discharge in SS6.2; propane production as well as antifouling agent and biocide production for SS6.3; atmospheric emission concerning SS6.3; ash management regarding processing (SS6.3); diesel oil, sawdust and bigbag production for final operations (SS6.4); and the final haulage of the CaCO 3 products for SS6.5. The main processes contributing to the potential environmental impacts are summarized in Figure 5.4, where a simplified contribution diagram is presented for mussel shell valorization (simplified contribution diagram for processes with a contribution greater than 1%).
Environmental assessment of mussel waste valorization 131 0% 20% 40% 60% 80% 100% ADP GWP ODP HTP FETP METP TETP POFP AP EP Initial haulage (SS6.1) Coagulant production (SS6.2) Electricity production (SS6.2) Sludge management (SS6.2) Propane production (SS6.3) Electricity production (SS6.3) Atmospheric emission (SS6.3) Ash management (SS6.3) Diesel oil production (SS6.4) Big-bag production (SS6.4) Sawdust production (SS6.4) Electricity production (SS6.4) Final haulage (SS6.5) Figure 5.4. Process contribution for mussel shell valorization (S6) As observed in Figure 5.4, propane production for processing arose as the main process contributing to ADP (36% of the total impact for this category) and ODP (42%). This process also involved relevant contributions to POFP (12%), AP (10%), HTP (20%) and METP (12%). Electricity production played a role in every impact category. Specifically, electricity production for final operations was found to be the main contributor to AP with 18% of the total impact for this category, ahead of electricity production for processing (17%) and electricity production for preliminary operations (16%). Electricity production for each of the subsystems (SS3.4, SS3.3 and SS3.2) also showed relevant contributions to POFP, ADP, GWP, ODP, HTP, FETP and METP, with percentages around 10% in every case. For GWP, sawdust production emerged as the main contributor. However, this contribution could be omitted since the company states that sawdust is originally a waste stream. Consequently, no emission should be allocated to sawdust, and it could be included as an empty process. Therefore, atmospheric emission within processing subsystem would become the real main contributor to GWP. In fact, it
Chapter 5 132 also involved relevant contributions to POFP (11% of the total impact for this category), AP (13%) and EP (5%). Sludge management was found as the main process contributing to POFP (22% of the total impact for this category), EP (83%) and TETP (86%). This process also contributed significantly to GWP (>10%), ODP (11%), AP (11%), HTP (4%) and FETP (13%). On the other hand, ash management was the process leading the potential contribution to three impact categories: HTP (20% of the total impact for this category), FETP (51%) and METP (51%). None of the haulage processes was found as the main contributor for any impact category. Nevertheless, haulage involved significant contributions to ADP, GWP, ODP, POFP, AP and HTP. Final haulage showed contribution percentages more than twice the percentages related to initial haulage. Finally, to a lesser extent, other processes contributed to the potential environmental impacts. For example, coagulant production accounted for a contribution of 2% to ODP and HTP. 5.3.2. Mussel organic waste valorization With regard to the environmental characterization of mussel organic waste valorization, the following processes were included: input transport, water supply as an ingredient, production of each of the ingredients (oil, egg albumen, skimmed milk powder, starch, salt, soya protein, aromas and spices), flocculant production, coagulant production, can production, cardboard production, packaging film production, additional water supply, electric energy production, thermal energy production, cardboard recycling, film recycling, tinplate management, sludge management, emissions to the environment, and product transport. The main processes contributing to the potential environmental impacts associated with mussel organic waste valorization are summarized in Figure 5.5 (simplified contribution diagram for processes with a contribution greater than 5%). It is observed that thermal energy production and raw material production were the key processes concerning potential environmental impacts.
Environmental assessment of mussel waste valorization 133 0% 20% 40% 60% 80% 100% ADP GWP ODP HTP FETP METP TETP POFP AP EP Input transport Production of raw materials Can production Cardboard production Electric energy production Thermal energy production Product transport Figure 5.5. Process contribution for mussel organic waste valorization Thermal energy production is linked to the thermal energy demand for (i) the cooking of non-boiled mussel organic waste, and (ii) the sterilization of cans. This process prevailed for the contribution to the toxicity and eco-toxicity categories, with 49% of the total impact for HTP, 33% for FETP, 61% for METP and 76% for TETP. Furthermore, thermal energy production presented relevant contribution percentages for AP (19%), ADP (18%), GWP (17%), POFP (16%) and ODP (15%). The term production of raw materials includes the production process for each of the ingredients (oil, egg albumen, skimmed milk powder, etc.). This set of processes accounted for the greatest contributions to EP (86% of the total impact for this category), POFP (56%), AP (45%), ODP (43%), GWP (39%) and ADP (30%). In particular, the contributions to EP and AP were mainly related to oil, egg albumen and skimmed milk powder production. Oil production and the production of aromas and spices were found to prevail for ADP. These processes along with skimmed milk powder production were the main sources for GWP and ODP. Finally, the contribution to POFP was mainly associated with the production of aromas and spices, as well as to the production of oil and soya protein. Raw material production also showed relevant contribution percentages
Chapter 5 134 for the toxicity and eco-toxicity categories, mainly due to the production of aromas and spices. Transport also played a role in the potential environmental impacts for S7. The transport related to inputs involved contribution percentages ranging from 5% (for EP) to 16% (for ADP), mainly due to the haulage of raw materials (ingredients) and cans. On the other hand, product haulage (mussel pâté transport) accounted for contributions ranging from 4% (for EP) to 14% (for ADP). Other processes should not be disregarded. For instance, the environmental impact contributions of electricity production ranged from 1% (for EP) to 12% (FETP). Can production also showed some relevant contributions to the potential environmental impacts, especially to ADP (10% of the total impact for this category) and GWP (7%). Note that the contributions associated with can production are strongly influenced by the chosen database. Another process related to the packaging format is cardboard production, which accounted for 7% of the total impact for ODP. To a lesser extent, emissions to air contributed to 3% of the total impact for GWP and to 2% for POFP. Similarly, packaging film production accounted for 3% of the total impact for ADP and for 1% of the impact for FETP and GWP. Flocculant production gave rise to 3% of the total impact for ODP. Finally, sludge management contributed to 1% of the impact for TETP. 5.4. Discussion and identification of improvement potentials 5.4.1. Mussel shell management From the environmental characterization of mussel shell valorization (S6), the corresponding hot spots were identified. These included (i) propane production for processing, (ii) sludge management, (iii) ash management, (iv) electricity production for final operations, processing and final operations, (v) initial and final haulage, and (vi) atmospheric emission linked to processing. On the basis of these remarks, the corresponding improvement potentials should be focused on the: Minimization of propane consumption or proposal and evaluation of new alternatives. Actions should be taken in the calcination process and in gas treatment.
Environmental assessment of mussel waste valorization 135 Use of processing ashes due to their high CaCO 3 content, and further research on sludge valorization. Optimization of the electricity demand for final operations, processing and preliminary operations. Logistical planning, especially for the final haulage of CaCO 3 products, but also for the initial haulage of raw materials. With the aim of dealing with system S6 in depth, a future scenario is presented for mussel shell valorization. This scenario was based on true trends according to personal communications from the valorization company. It included three hypothetical improvement actions of environmental and economic interest: Use of glycerine instead of propane for the calcination process in SS6.3. In order to implement this alternative, it was necessary to determine the glycerine and propane needs along with the corresponding atmospheric emissions. This was made from internal reports of the mussel shell waste valorization plant and other sources dealing with glycerine combustion (Metzger 2007; Patzer 2007; Aqua-Fuel Research 2008; Bluer 2008). It should be stressed that the management of 100 tonnes of mussel shell waste would involve the use of 13.40 tonnes of glycerine; furthermore, 227 kg of propane would be needed for pre-combustion. Assumption of 100% of the processing ashes as a sub-product instead of as a waste stream. Currently, the entire ash production is managed by disposal to opencast refill. However, according to company reports, these ashes have a high CaCO 3 content (80-85%), and this is the reason why their appreciation as a sub-product could be assumed as the equality among the amount of ashes produced and the same amount of CaCO 3 as an avoided product (background process from the ecoinvent database). Dispatch of 100% of the sludge to its valorization. Currently, the sludge management entails being sent to landfill. However, in the future scenario, the entire sludge production undergoes filtration, settling and dehydrating in order to produce an agricultural fertilizer mainly used for cereal crops, roughly 30% for wheat and barley fields, 68% for meadows and 2% for alfalfa (Camino 2004). On the basis of internal reports, the sludge from preliminary operations (SS6.2) is 70% water. Consequently, with an additional energy supply of 176.57 kWh (ACS 2008), the amount of sludge assigned to valorization (2.5
Chapter 10 238 Sustainable Development (WBCSD) together with the World Resources Institute (WRI), the UNEP/SETAC Life Cycle Initiative, the British Standards Institution (BSI), the Japanese Ministry of Economy, Trade and Industry (METI), and the French Environment and Energy Management Agency (ADEME). Behind this stream of proposals is the involvement of high-profile retailers such as Tesco, Marks & Spencer or Carrefour, which are interested in implementing a CF scheme for their products. In order to define a common standard for the assessment of GHG emissions associated with products (goods and services), the BSI, the Carbon Trust and the Department for Environment, Food and Rural Affairs (Defra, United Kingdom) started in 2007 a procedure that gave birth to the Publicly Available Specification 2050:2008 (BSI 2008), together with other complementary documents such as the Guide to PAS 2050 (Carbon Trust et al. 2008). PAS 2050 specifies requirements for the assessment of the life cycle GHG emissions of goods and services based on key life cycle techniques and principles. Thus, PAS 2050 builds on the LCA guidance and requirements articulated in ISO 14040:2006 and ISO 14044:2006, adopting a life cycle approach to emissions assessment and the functional unit as the basis of any reporting (Sinden 2009). Furthermore, this specification also deals with other relevant methods and approaches in the field of GHG assessment such as ISO 14064 (ISO 2006c, 2006d, 2006e), IPCC publications (IPCC 2006, 2007) and the GHG Protocol (WRI/WBCSD 2004). 10.1.2. CF applications and implications Direct applications of CF for companies include (Carbon Trust et al. 2008): Internal assessment of product life cycle GHG emissions and subsequent reduction. Incorporation of emissions impact into decision making regarding suppliers, materials, product design, manufacturing processes, etc. Support for corporate responsibility reporting. Identification of cost savings opportunities. Benchmarking for measuring and communicating emission reductions. Support for comparison of product-level GHG emissions.
Assessment of the carbon footprint 239 Moreover, if a company decides to communicate the carbon footprint of any of its products, then customers become aware of how their purchasing decisions influence GHG emissions (Carbon Trust 2008). In this sense, communication is often used to gain market access and competitiveness. Traditional environmental labelling schemes award an environmental label to those products that are judged to be less harmful to the environment than others within the same product group. To be awarded a label, a product has to meet a set of environmental criteria established for its product group by the labelling scheme organizer (Andersson 1998). These criteria relate to the complete product lifecycle. The use of LCA has proved to be suitable when analyzing the performance of food products to identify key environmental issues in support of the development of ecolabelling criteria (Mungkung et al. 2006). Furthermore, CF for food products is expected to boom due to the relevant contribution of food GHG emissions to global emissions (Garnett 2008, 2009). Labelling should not be limited to the products considered least harmful, but it should cover all products. Therefore, in the near future, an additional role of policy makers could consist in encouraging global warming mitigation by promoting that economic actors within the food chain undertake CF schemes for their products according to a standardized procedure. This measure would foster the diffusion of life cycle thinking and LCA within firms, and could be the seed for a more consistent framework for the environmental assessment of products and services (Weidema et al. 2008). However, these schemes should not be used as a barrier for trading. For example, regarding developing countries, costly technical and organizational measures should be partially supported by stakeholders in the industrialized countries since they must be the main driver for the use of these schemes (Mungkung et al. 2006). Besides, the development of carbon labels for food products should also take into account the vulnerability of distant developing countries with a high level of substitutable exports. This vulnerability is the reason why developing countries accounting for substitutable food exports which demand long run transport identify CF as a current matter of concern (CF-Thailand 2008; Saunders & Barber 2008; Edwards-Jones et al. 2009). This concern is motivated by the retailers’ desire of implementing CF schemes in the short term; in fact, retailers have arisen as the most determinant actor to extend the use of carbon footprints (Clift et al. 2005).
Chapter 10 240 An example of the international interest in carbon labelling is that Planet Ark and the Carbon Trust have launched the Carbon Reduction Label in Australia in order to allow businesses, who independently verify the carbon footprints of their products, to communicate their carbon reduction commitment to their customers through an easy-to-understand label that appears on a product’s packaging and other marketing material. The scheme aims to help companies reduce their costs and enhance their reputation through communicating their product carbon footprints (Planet Ark 2009). Previous studies on the use of LCA in environmental policy suggest that LCA works better as a conceptual or facilitative instrument than as a tool for gaining definitive support for specific policies (Heiskanen 1999). In this regard, the current popularity of CF should not alter the nature of LCA, which is a tool rather than an all-encompassing solution. Otherwise, an inadequate use of LCA could lead to skewed policy decisions (Garnett 2008). Within this context, this chapter develops the carbon footprint for a canned mussel product following the PAS 2050 method. This case study arises as a good example for policy makers to understand the opportunities provided by CF. Moreover, results facilitate the task of mussel processors to implement CF schemes into their commercial activities. 10.2. Justification and presentation of the case study The goal of the current case study is to quantify the carbon footprint of the most common canned mussels’ format: the triple pack of round cans. As presented in Section II of this dissertation, the Galician mussel sector and, in particular, canned mussels’ activities are of high relevance at regional, national and international scale. Galician rafts produce 98% of the mussels farmed in Spain. Not surprisingly, mussels ( Mytilus galloprovincialis ) are the single largest cultured shellfish in Galicia (Xunta de Galicia 2008). Fresh, canned and frozen mussels are the main mussel-based products. Specifically, 40% of the total production ends as canned mussels (Tirado & Macias 2006). Spanish canning factories obtain more than 90% of the mussel input from Galicia (MAPA 2007) and produce around 35,000 tonnes of canned mussels per year and a turnover of 66 million euros (Franco 2006).
Assessment of the carbon footprint 241 Regarding product distribution, only 15% of the Galician mussel production is exported. In particular, France is the main foreign destination for Galician canned mussels, followed by Germany, Mexico, Portugal or the USA (Conde 2007). This figure does not suggest an export-based vulnerability to the development of carbon labels for mussel products. However, what is certainly highlighted as one of the major concerns within the Galician mussel sector is the threat of cheaper mussel products arriving from Chile (Estévez 2008). In this sense, the implementation of a CF scheme for the Galician mussel products could be adopted by regional mussel farmers and processors as a marketing strategy to reinforce their market position. This measure would answer the need for further product differentiation and would also anticipate future regulations on global warming. 10.3. Application to canned mussels At this point in the chapter, the objective is to calculate the final value for the carbon footprint of the triple pack of round cans of mussels. 10.3.1. Method adopted for the CF of canned mussels PAS 2050 was used as a reference method to conduct the CF of the triple pack of canned mussels. As shown in Figure 10.1, this specification distinguishes two different approaches for the assessment of life cycle GHG emissions for products (BSI 2008): The “cradle-to-grave” approach is named business-to-consumer (B2C) assessment. This implementation mode includes the emissions arising from the full life cycle of the product. The “cradle-to-gate” approach is named business-to-business (B2B) assessment. This mode comprises all upstream emissions and stops at the point where the product is delivered to a new organization. The four basic steps to calculate the carbon footprint of any good or service include (Carbon Trust et al. 2008): (i) building a process map, (ii) checking boundaries and prioritization, (iii) collecting data, and (iv) calculating the carbon footprint. There is an optional final step where technical uncertainty is checked in order to improve confidence in footprint comparisons and in any decisions that are made based on the footprint.
Chapter 10 242 Figure 10.1. Approaches for CF (adapted from Carbon Trust et al. 2008) 10.3.2. Calculation of the carbon footprint for canned mussels First of all, the CF approach must be selected. In this sense, unless the target good is used as an input to multiple final products with a wide range of uses and disposal characteristics, a B2C approach is preferred to a B2B assessment because of its comprehensive nature. Consequently, a B2C approach should be followed for canned mussels and, in general, for food products. Building a process map The first step pursues the identification of all materials, activities and processes which give rise to the life cycle GHG emissions associated with the target product. The building of a process map, as exhaustive as possible to include all possible drivers of GHG emissions, helps to achieve this goal. In the first place, the product and the functional unit are defined. Most canned mussels are usually presented to the consumer under a triple pack of round cans format. Hence, the FU is one triple pack of round cans of canned mussels, made up of 129 g of canned mussel flesh, 120 g of sauce, 81 g of primary packaging (tinplate cans), and 12.73 g of secondary packaging (cardboard). All these materials are traced back to their origin (Figure 10.2). Canned mussel processing does not entail co-products, since mussel shells and mussel organic Raw materials Raw materials B2B APPROACH Manufacture Manufacture Distribution / Retail Distribution to business customer Consumer use Disposal / Recycling B2 C APPROACH
Assessment of the carbon footprint 243 remains are waste streams sent to valorization plants for management. All waste flows and emissions are accounted for, as well as storage and waste transport. SECTIO S10 PROCESSING IN THE CANNING FACTORY CAN PRODUCTION MUSSEL SHELL+DEBRIS TREATMENT MUSSEL ORGANIC WASTE TREATMENT Shell Organic remains Wastewater PACKAGING IN THE CANNING FACTORY WASTEWATER TREATMENT RETAIL CONSUMPTION MSW MANAGEMENT W I WT T SECTION S1 T W I WT T SECTION S2 T W I WT T SECTION S3 T W I WT T SECTION S4 T W I WT T SECTION S5 T W I WT T SECTION S6 T T T T T T PRODUCTION OF OTHER INPUTS W I WT T SECTION S7 T T BOILER OPERATION W I WT T SECTION S8 T PREMISES AND AUXILIARY OPERATIONS W I WT T SECTION S9 T W WT T CAN RECYCLING CARDBOARD RECYCLING I T T W WT T SECTION S11 T I T W T WT SECTION S12 I T W WT T SECTION S13 T I T W WT T CARDBOARD PRODUCTION T I T W WT T I T T SECTION S14 SECTION S15 WT W T SECTION S16 SECTION S17 Cans to recycling I T Cardboard to recycling Municipal solid waste (MSW) T T T SECTION S18 PRODUCTION OF OTHER INGREDIENTS MUSSEL FARMING OLIVE OIL PRODUCTION SUNFLOWER OIL PRODUCTION SOYA OIL PRODUCTION WATER SUPPLY SECTION S20 SECTION S19 SECTION S21 Figure 10.2. Initial process map for the case study. Dotted lines represent sections. I = inputs; T = transport; W = waste; WT = waste treatment
Chapter 10 244 Regarding the consumer use stage, PAS 2050 excludes consumer transport. Canned mussels do not require cooking before consumption, refrigeration or freezing. Hence, the term consumption in Figure 10.2 only considers the production of the plastic bag used for shopping. Additionally, the use stage includes municipal solid waste management as well as the management of the packaging materials. Checking boundaries and prioritization This step determines the life cycle stages that are definitely included in the assessment. With this purpose, a preliminary assessment of the sources of GHG emissions is undertaken for all processes presented in the initial process map. According to PAS 2050, this initial estimate of GHG emissions is named “anticipated life cycle GHG emissions” and is calculated by means of secondary data or through a combination of primary and secondary data. The term secondary data relates to information obtained from sources other than direct measurement of the processes included in the life cycle of the product (BSI 2008). Contributions for any source of GHG emissions resulting in ≤1% of the anticipated life cycle GHG emissions of the product (called “immaterial contributions”) are excluded from the system boundaries provided that the total proportion of immaterial emission sources does not exceed 5% of the anticipated life cycle GHG emissions. Table 10.1 presents the identification of immaterial contributions for the case study. As required by PAS 2050, the anticipated life cycle GHG emissions are estimated separately for the use phase. In order to simplify the presentation, the anticipated results are shown for sections and not for single processes, together with the data source used in each case. The values of global warming potentials (GWP100) to transform GHGs emission in kg of CO 2 e are in accordance with the latest ones available from the IPCC (IPCC 2007). SimaPro 7 was the software used for the computation of the anticipated carbon footprint (Goedkoop et al. 2008). As observed in Table 10.1, ecoinvent was chosen as the preferred database for secondary activity data (Frischknecht et al. 2007a). PAS 2050 gives preference to the use of data verified as being compliant with this PAS; however, a complete set of verified data is not yet available.
Assessment of the carbon footprint 245 Table 10.1. Anticipated life cycle GHG emissions of the FU Section assessed kg CO 2 e/FU Main data source Anticipated contribution (%) Contribution type PREVIOUS TO COSUMPTIO S1) Mussel farming 8.83·10 -2 Chapter 3 2.00 Material S2) Olive oil production 6.41·10 -3 Nicoletti et al. (2001) 0.14 Immaterial S3) Sunflower oil production 8.27·10 -3 Nicoletti et al. (2001) 0.19 Immaterial S4) Soya oil production 3.79·10 -3 ecoinvent database (Jungbluth et al. 2007) 0.09 Immaterial S5) Tap water supply 2.77·10 -5 ecoinvent database (Althaus et al. 2007) 0.00 Immaterial S6) Production of other ingredients 1.54·10 -4 ecoinvent database (Althaus et al. 2007) 0.00 Immaterial S7) Production of other inputs 1.53·10 -4 ecoinvent database (Althaus et al. 2007) 0.00 Immaterial S8) Boiler operation 5.68·10 -2 Chapter 4 1.28 Material S9) Premises and auxiliary operations 8.60·10 -4 Chapter 4 0.02 Immaterial S10) Processing in the canning factory 6.96·10 -2 Chapter 4 1.57 Material S11) Mussel shell and debris treatment 1.16·10 -1 Chapter 5 2.62 Material S12) Mussel organic waste treatment -1.59·10 -3 Adapted from LCA food data base (Nielsen et al. 2003) -0.04 Immaterial S13) Wastewater treatment 6.11·10 -3 Chapter 4 0.14 Immaterial S14) Can production 3.95 ecoinvent database (Classen et al. 2007) BUWAL 250 database (Spriensma 2004) 89.25 Material S15) Cardboard production 9.62·10 -3 ecoinvent database (Hischier 2007) 0.22 Immaterial S16) Packaging in the canning factory 6.59·10 -2 Chapter 4 1.49 Material S17) Retail 4.50·10 -2 Transport: Chapter 4 Retail: LCA food data base (Nielsen et al. 2003) 1.02 Material TOTAL PRE-CONSUMPTION 4.42 100.00
Chapter 10 246 Table 10.1. Anticipated life cycle GHG emissions of the FU (cont.) Section assessed kg CO 2 e/FU Main data source Anticipated contribution (%) Contribution type COSUMPTIO STAGE S18) Consumption (polyethylene bag production) 7.88·10 -4 ecoinvent database (Hischier 2007) 2.16 Material S19) Can recycling - Already involved in S14 - - S20) Cardboard recycling - Already involved in S15 - - S21) Municipal solid waste management 3.58·10 -2 ecoinvent database (Doka 2007) 97.84 Material TOTAL CONSUMPTION 3.66·10 -2 100.00 ANTICIPATED CARBON FOOTPRINT = 4.46 kg CO 2 e/FU The choice of ecoinvent as the preferred database totally determines the result of the anticipated assessment. The use of the ecoinvent database for the tinplated sheet in section S14 (can production) is especially relevant. In this sense, if an older database such as BUWAL 250 (Spriensma 2004) is selected for can tinplate production, the contribution of S14 to the anticipated life cycle GHG emissions is lower (although this element is still the most important one) and, consequently, new material contributions arise. Thus, when using BUWAL 250, sunflower oil production results in a material contribution, accounting for an anticipated contribution of 1.11%. In this context of result variability due to database selection, the ecoinvent database was used when possible, as it is considered the most updated and complete available database. Nevertheless, section S3 (sunflower oil production) was included within the material contributions despite its low anticipated contribution percentage in Table 10.1. The inclusion of section S3 can be understood as a safety measure to avoid the omission of a potentially relevant contributor. Hence, concerning the stages previous to consumption, all material contributions accounted for 99.42% of the anticipated life cycle GHG emissions and, therefore, a factor of 1.006 is required to scale the final GHG emissions in order to take into account the excluded activities. Regarding the use phase, sections S19 and S20 were omitted given that the recycling of packaging materials was already incorporated in the raw material content of cans (section S14) and cardboard (section S15). The rationale behind
Assessment of the carbon footprint 247 this decision is that the avoided emissions associated with the use of a percentage of metal scrap in cans and of paper-cardboard waste in carton are already implemented in sections S14 and S15, where a virtual closed loop recycling is assumed. In the use stage, material contributions accounted for 100% of the anticipated life cycle GHG emissions and, therefore, no scaling factor is required. PROCESSING IN THE CANNING FACTORY MUSSEL FARMING CAN PRODUCTION MUSSEL SHELL+DEBRIS TREATMENT Shell PACKAGING IN THE CANNING FACTORY RETAIL CONSUMPTION MSW MANAGEMENT W I WT T SECTION S1 T SUNFLOWER OIL PRODUCTION W I WT T SECTION S3 T T T BOILER OPERATION W I WT T SECTION S8 T I T T W WT T SECTION S11 T I T W WT T I T T SECTION S14 WT W T Municipal solid waste T SECTION S21 SECTION S18 SECTION S17 W WT T SECTION S16 SECTION S10 I T Figure 10.3. Final process map after ruling out immaterial contributions. Dotted lines represent sections. Black boxes highlight the activities requiring primary activity data. I= inputs; T = transport; W = waste; WT = waste treatment
Chapter 10 254 counter-productive, fortunately the current trend is to take PAS 2050 specifications as the master guidelines that conduct the product carbon footprint assessment. In this sense, the development of the future ISO 14067 standard for quantification and communication of product carbon footprints draws on PAS 2050. 10.5. Conclusions and perspectives In this chapter, CF was proved to be a useful tool for the internal assessment of life cycle GHG emissions. Moreover, it led to the identification of opportunities to reduce these emissions. In this sense, CF arises as a potential support for decision making in companies, even though it provides a limited view of the environmental performance of a product since global warming is the only impact category assessed. Despite this drawback, the greatest strength of CF lies in the use of a life-cycle approach and in its popularity. Therefore, it is possible to think of product policies that promote the implementation of CF schemes. These policies should not be understood as definitive but as a provisional vehicle to a more comprehensive policy framework for the environmental assessment of products based on their life cycle. In the short term, companies are expected to incorporate CF schemes for their products as a strategic measure for both marketing and decision making. This practice will be performed by following a well-defined method which guarantees traceability, comparability and a proper communication. PAS 2050 seems to be ahead in this field. In the long run, policy makers should pursue the commitment of companies to undertake CF schemes as facilitative instruments within their activity. Undoubtedly, the path is open for CF. 10.6. References ADEME (2007). “Bilan Carbone TM – Quantify emissions, anticipate action”. French Environment and Energy Management Agency, France. <www.ademe.fr/bilan-carbone> Althaus, H.J., Chudacoff, M., Hischier, R., Jungbluth, N., Osses, M., Primas, A. (2007). “Life Cycle Inventories of Chemicals”. ecoinvent report No. 8, v2.0, Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland
Assessment of the carbon footprint 255 Andersson, I. (1998). “Environmental management tools for SMEs: A handbook”. Environmental Issues Series, European Environment Agency Ayer, N.W., Côté, R.P., Tyedmers, P.H., Willison, J.H.M. (2009). “Sustainability of seafood production and consumption: an introduction to the special issue”. J Clean Prod 17, 321-324 BSI, British Standards Institution (2008). “PAS 2050:2008 – Specification for the assessment of the life cycle greenhouse gas emissions of goods and services” Carbon Trust (2008). “Code of good practice for product greenhouse gas emissions and reduction claims” Carbon Trust, Department for Environment, Food and Rural Affairs, British Standards Institution (2008). “Guide to PAS 2050 – How to assess the carbon footprint of goods and services” Cederberg, C. (1998). “Life Cycle Assessment of Milk Production – A comparison of conventional and organic farming”. SIK-Rapport 1998 Nr 643, The Swedish Institute for Food and Biotechnology, Gothenburg, Sweden CF-Thailand (2008). Web of the project “Capacity building of Thai food industries on ‘carbon footprint labelling’ to promote the development of lowcarbon trade between EU and Thailand for climate change mitigation”. <www.carbonlabelthaifood.sci.ku.ac.th> Classen, M., Althaus, H.J., Blaser, S., Tuchschmid, M., Jungbluth, N., Doka, G., Faist Emmenegger, M., Scharnhorst, W. (2007). “Life Cycle Inventories of Metals”. ecoinvent report No. 10, v2.0, Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland Clift, R., Malcolm, R., Baumann, H., Connell, L., Rice, G. (2005). “Eco-labels and Electric Monks”. J Ind Ecol 9 (3), 4-7 Comesaña, M. (2009). Personal communication. Metalgrafica Gallega plc Conde, A. (2007). “The Spanish mussel sector”. <www.havbrukskompaniet.no> Doka, G. (2007). “Life Cycle Inventories of Waste Treatment Services”. ecoinvent report No. 13, v2.0, Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland Dones, R., Bauer, C., Bolliger, R., Burger, B., Faist Emmenegger, M., Frischknecht, R., Heck, T., Jungbluth, J., Röder, A., Tuchschmid, M. (2007). “Life Cycle Inventories of Energy Systems: Results for Current Systems in Switzerland and other UCTE Countries”. ecoinvent report No. 5, v2.0, Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland Ecoacero (2009). Spanish Ecological Association for the Recycling of Tinplate. <www.ecoacero.com/menu_reciclado.htm>
Chapter 10 256 Edwards-Jones, G., Plassmann, K., York, E.H., Hounsome, B., Jones, D.L., Milà i Canals, L. (2009). “Vulnerability of exporting nations to the development of a carbon label in the United Kingdom”. Environ Sci Policy 12 (4), 479-490 Elsayed, M.A., Grant, J.F., Mortimer, N.D. (2002). “Energy use in the United Kingdom non-domestic building stock: 2002 catalogue of results”. Final report for the Global Atmosphere Division of the Department for the Environment, Food and Rural Affairs, United Kingdom EPLCA (2007). “Carbon Footprint – what it is and how to measure it”. European Platform on Life Cycle Assessment, European Commission Estévez, R. (2008). “El mejillón de Chile desplaza del mercado a un 20% del gallego” (in Spanish). La Voz de Galicia journal, 7 August 2008 Finkbeiner, M. (2009). “Carbon Footprinting – opportunities and threats”. Int J Life Cycle Ass 14, 91-94 Franco, M. (2006). “A miticultura en Galicia: unha actividade de éxito e con futuro” (in Galician). Revista Galega de Economía 15 (1), 251-256 Frischknecht, R., Jungbluth, N., Althaus, H.J., Doka, G., Heck, T., Hellweg, S., Hischier, R., Nemecek, T., Rebitzer, G., Spielmann, M., Wernet, G. (2007a). “Overview and Methodology”. ecoinvent report No. 1, v2.0, Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland Frischknecht, R., Althaus, H.J., Bauer, C., Doka, G., Heck, T., Jungbluth, N., Kellenberger, D., Nemecek, T. (2007b). “The environmental relevance of capital goods in Life Cycle Assessments of products and services”. Int J Life Cycle Ass 12 (1), 7-17 Garnett, T. (2008). “Cooking up a storm. Food, greenhouse gas emissions and our changing climate”. Report of the Food Climate Research Network, University of Surrey, United Kingdom Garnett, T. (2009). “Livestock-related greenhouse gas emissions: impacts and options for policy makers”. Environ Sci Policy 12, 491-503 Goedkoop, M., de Schryver, A., Oele, M. (2008). “Introduction to LCA with SimaPro 7”. PRé Consultants, the Netherlands Heiskanen, E. (1999). “Every product casts a shadow: but can we see it, and can we act on it?”. Environ Sci Policy 2, 61-74 Hischier, R. (2007). “Life Cycle Inventories of Packagings and Graphical Papers”. ecoinvent report No. 11, v2.0, Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland Iles, A. (2007). “Making the seafood industry more sustainable: creating production chain transparency and accountability”. J Clean Prod 15, 577-589
Assessment of the carbon footprint 257 IPCC (2006). “Guidelines for National Greenhouse Gas Inventories”. National Greenhouse Gas Inventories Programme, Intergovernmental Panel on Climate Change IPCC (2007). “Climate change 2007: the physical science basis”. In: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M., Miller, H.L. (eds.). Contribution of working group I to the fourth assessment report of the Intergovernmental Panel on Climate Change, Chapter 2, Cambridge University Press, United Kingdom IPE (2009). Spanish Paper Institute. <www.ipe.es/upload/estadisticas.pdf> ISO, International Organization for Standardization (2006a). ISO 14040:2006. Environmental management – Life Cycle Assessment – Principles and framework ISO, International Organization for Standardization (2006b). ISO 14044:2006. Environmental management – Life Cycle Assessment – Requirements and guidelines ISO, International Organization for Standardization (2006c). ISO 14064-1:2006. Greenhouse gases – Part 1: Specification with guidance at the organization level for quantification and reporting of greenhouse gas emissions and removals ISO, International Organization for Standardization (2006d). ISO 14064-2:2006. Greenhouse gases – Part 2: Specification with guidance at the project level for quantification, monitoring and reporting of greenhouse gas emission reductions or removal enhancements ISO, International Organization for Standardization (2006e). ISO 14064-3:2006. Greenhouse gases – Part 3: Specification with guidance for the validation and verification of greenhouse gas assertions Jungbluth, N., Chudacoff, M., Dauriat, A., Dinkel, F., Doka, G., Faist Emmenegger, M., Gnansounou, E., Kljun, N., Schleiss, K., Spielmann, M., Stettler, C., Sutter, J. (2007). “Life Cycle Inventories of Bioenergy”. ecoinvent report No. 17, v2.0, Swiss Centre for Life Cycle Inventories, Dübendorf, Switzerland MAPA (2007). “Libro Blanco de la Pesca” (in Spanish). Ministry of Agriculture, Fisheries and Food, Spain. <www.mapa.es> Mungkung, R.T., Udo de Haes, H.A., Clift, R. (2006). “Potentials and limitations of Life Cycle Assessment in setting ecolabelling criteria: A case study of Thai shrimp aquaculture product”. Int J Life Cycle Ass 11 (1), 55-59
Chapter 10 258 Nicoletti, G.M., Notarnicola, B., Tassielli, G. (2001). “Comparative LCA of virgin olive oil vs. seed oils”. Proceeding of the International Conference on LCA in Foods, Gothenburg, Sweden Nielsen, P.H., Nielsen, A.M., Weidema, B.P., Dalgaard, R., Halberg, N. (2003). “LCA food data base”. <www.lcafood.dk> Pelletier, N.L., Ayer, N.W., Tyedmers, P.H., Kruse, S.A., Flysjo, A., Robillard, G., Ziegler F., Scholz, A.J., Sonesson, U. (2007). “Impact categories for Life Cycle Assessment research of seafood production systems: Review and prospectus”. Int J Life Cycle Ass 12 (6), 414-421 Planet Ark (2009). <http://carbonreductionlabel.com.au> Sainz, H., Sanz, A., Vera, D., Martín-Cerdeño, V.J. (2008). “Alimentación en España, 2008. Producción, industria, distribución y consumo” (in Spanish). Empresa Nacional Mercasa – Distribución y Consumo, Madrid, Spain Saunders, C., Barber, A. (2008). “Carbon footprints, life cycle analysis, food miles: Global trade trends and market issues”. Polit Sci 60 (1), 73-88 SETAC Europe LCA Steering Committee (2008). “Standardisation Efforts to Measure Greenhouse Gases and 'Carbon Footprinting' for Products”. Int J Life Cycle Ass 13 (2), 87-88 Shonfield, P.K.A., Dumelin, E.E. (2005). “A life cycle assessment of spreads and margarines”. Lipid Technol 17 (9), 199-203 Sinden, G. (2009). “The contribution of PAS 2050 to the evolution of international greenhouse gas emission standards”. Int J Life Cycle Ass 14, 195-203 Spriensma, R. (2004). “SimaPro Database Manual. The BUWAL 250 library”. PRé Consultants, the Netherlands Tirado, C., Macias, J.C. (2006). “Cultivo de mejillón. Aspectos generales y experiencias en Andalucía” (in Spanish). Regional Ministry of Agriculture and Fisheries, Andalucia, Spain Weidema, B.P., Thrane, M., Christensen, P., Schmidt, J., Løkke, S. (2008). “Carbon Footprint: A Catalyst for LCA?”. J Ind Ecol 12 (1), 3-6 WRI/WBCSD (2004). “The greenhouse gas protocol: a corporate accounting and reporting standard”. World Resources Institute/World Business Council for Sustainable Development (eds.), Washington, United States Xunta de Galicia (2008). “Anuario de Pesca Galicia 2007” (in Galician). Regional Ministry of Fisheries and Sea Affairs, Galicia, Spain
SECTIO V. GEERAL COCLUSIOS
General conclusions 261 Chapter 11 General conclusions The path towards sustainability in the food sector demands the modification of the current operational and environmental patterns. In this sense, it is necessary to pursue reductions in the consumption levels for materials and energy, as well as the mitigation of the corresponding environmental impacts. Within this context, LCA arises as a technique for assessing the environmental aspects and potential impacts associated with a product by compiling an inventory of relevant inputs and outputs of a product system, evaluating the potential environmental impacts associated with those inputs and outputs and interpreting the results of the inventory analysis and impact assessment phases in relation to the objectives of the study. This doctoral thesis contributes to the gradual establishment of LCA to evaluate seafood production systems by widening the range of species studied and developing further potentials in the application of LCA such as the combined use of DEA and LCA, or the implementation of CF schemes. The application of LCA to the Galician mussel ( Mytilus galloprovincialis ) and turbot ( Scophthalmus maximus ) aquaculture sectors proved the suitability of LCA to assess the environmental performance of these key economic sectors. In this respect, the use of LCA provided chain transparency and accountability all along the trade chain for mussels and turbot. Mussels are the leading product of the Galician aquaculture. This bivalve mollusc is cultured in rafts according to an extensive aquaculture practice. Mussel culture gives rise to a complex sector involving not only farming but also a variety of activities that are performed by different economic actors depending on the processing alternative selected for mussel transformation. The novel LCA of the Galician mussel sector led to these key messages and conclusions: Average models for rafts and auxiliary boats for mussel culture were defined on the basis of real in situ data from a set of vessels that operate in the main production areas.
Chapter 11 262 Detailed inventories are now available for mussel farming, mussel processing (in canning factories, cooking-freezing plants and partial canning factories), mussel consumption in households (as fresh, canned and frozen mussels), and mussel waste valorization (valorization of mussel shells to produce calcium carbonate, and valorization of mussel organic remains to produce pâté). The dispatch centres sub-sector was found to be the most contributing to the potential environmental impacts when capturing the real market scenario for mussels. On the contrary, the cooking plants and canning factories sub-sectors entailed lower impact contributions when compared to the culture and dispatch centres sub-sectors. Mussel shell valorization and mussel organic waste management contribute to the potential environmental impacts to a lesser extent than mussel culture, mussel purification and, generally, mussel transformation in canning factories. Minimization of electricity use in dispatch centres is of paramount importance. Improvement actions for mussel culture should be focused on the optimization of the diesel demand for vessel operation as well as on the minimization of the energy and iron demand for capital goods. Fresh mussels were the mussel product with the potentially least favourable environmental profile when compared to canned and frozen mussels on the basis of a same protein supply. This higher potential environmental impact is closely linked to mussel purification within dispatch centres. Regarding the Galician intensive aquaculture, turbot is the main species. Turbot farming in Galicia accounts for around 90% of the national turbot production. As an intensive aquaculture practice, turbot farming demands external feeding. General conclusions from the application of LCA to aquafeed production and turbot aquaculture include: Inventories for the production of both marine and continental aquafeed were provided, together with thorough inventories for turbot farming (hatching and nursing, growing, ongrowing) and consumption. Recommendations for aquafeed manufacturers are centred on raw material production. New raw materials and/or different ingredient ratios for aquafeed should be assessed.
General conclusions 263 Electricity use in hatching facilities is the main hot spot within turbot aquaculture, ahead of aquafeed and diesel use in ongrowing plants. Hence, turbot farmers should pursue the minimization of the electricity demand in these facilities. A rough comparison between intensive and extensive aquaculture sectors was established by assuming turbot and mussels as their respective representatives. Extensive aquaculture showed a potentially worse environmental profile, mainly due to the unsustainable electricity use in mussel dispatch centres and to the role played by capital goods for mussel culture. In addition to the application of LCA to mussel and turbot aquaculture sectors, further potentials in the use of LCA were developed, specifically the combined application of LCA and DEA, and the assessment of carbon footprints. DEA is a performance measurement methodology used to empirically quantify the comparative productive efficiency of multiple similar entities. This tool featured appealing potentials when jointly applied with LCA. The key messages on the application of LCA+DEA methodology are: An LCA+DEA approach joins the strengths and minimizes the weaknesses attributable to both methodologies so that a synergistic effect is achieved while maintaining a quantitative character. The strength of LCA+DEA methodology comes from its quantitative character since it is able to set targets and quantify potential improvements. The use of an LCA+DEA approach avoids the use of average inventories when assessing a high number of similar facilities. Consequently, undesirable standard deviations are prevented. LCA+DEA methods are not limited to environmental impacts but add an economic dimension to the sustainability assessment. The five-step LCA+DEA method developed in this doctoral thesis arises as a tool for eco-efficiency verification. This approach quantifies the environmental consequences of operational inefficiencies. The application of the five-step LCA+DEA method to Galician mussel cultivation sites proved the direct link between operational efficiency and environmental impacts. Operationally inefficient rafts were identified and
Annex I iv (instalaciones y equipos). El consumo de diesel para la operación de la embarcación resultó ser el principal motivo de los impactos ambientales potenciales, junto con el uso de energía y hierro para los bienes capitales. No obstante, se necesitaría un estudio más pormenorizado de los bienes capitales. El cultivo de mejillón da lugar a un complejo sectorial que no sólo incluye las actividades acuícolas sino también un entramado de actividades ligadas al procesado del mejillón. A este respecto, además del subsector de cultivo de mejillón, se pueden distinguir tres subsectores principales en función de los centros donde tiene lugar la transformación del mejillón: (i) subsector de las estaciones depuradoras de moluscos, (ii) subsector de las empresas conserveras, y (iii) sub-sector de los cocederos de mejillón y empresas conserveras parciales (es decir, conserveras que reciben la vianda de mejillón ya cocida). El Capítulo 4 incluye la evaluación ambiental mediante ACV del procesado y consumo de mejillón. La elaboración y uso de inventarios exhaustivos condujo a la caracterización ambiental del sector mejillonero en términos de la contribución de cada uno de los subsectores a los impactos ambientales potenciales. En este sentido, el subsector de las estaciones depuradoras de moluscos (responsables del suministro de mejillón fresco) contó con las mayores contribuciones, claramente por delante del subsector de cultivo. Los subsectores de las empresas conserveras y de los cocederos de mejillón presentaron unas contribuciones mucho menores. Los potenciales de mejora propuestos destacaron la necesidad de minimizar el consumo de energía eléctrica en las estaciones depuradoras de moluscos. Por otra parte, se llevó a cabo un ACV comparativo a fin de contrastar el perfil ambiental de los tres principales productos de mejillón. Así, este análisis concluyó que los mejillones frescos conllevan el perfil ambiental más desfavorable cuando son comparados con los mejillones en conserva y con los mejillones congelados. El procesado del mejillón da lugar a una serie de residuos específicos de la industria mejillonera. Entre estos residuos, destacan la concha de mejillón y los restos orgánicos de mejillón. El Capítulo 5 trata la gestión tanto de la concha como de los restos orgánicos de mejillón desde un enfoque de ACV. Por una parte, se procedió a la caracterización ambiental de la valorización de la concha de mejillón para producir carbonato cálcico. Consecuentemente, el consumo de propano y energía eléctrica, la gestión del lodo y las cenizas, el transporte y las emisiones atmosféricas fueron identificados como los puntos ambientalmente críticos donde deberían centrarse los potenciales de mejora. En este sentido, se
Resumen v realizó la evaluación ambiental de un escenario futuro para estimar las consecuencias ambientales potenciales en el caso de adoptar tres medidas concretas: uso de glicerina en vez de propano, consideración de las cenizas de proceso como un producto y no como un residuo, y valorización del lodo. El ACV reflejó que dicho escenario futuro podría suponer un peor desempeño ambiental con respecto a la situación actual, a menos que solamente se adoptasen las medidas concernientes a las cenizas y al lodo. Además, se evaluó ambientalmente la conveniencia de la valorización de la concha de mejillón en comparación con otras alternativas para la gestión de residuos (vertedero e incineración). La incineración resultó ser la opción menos favorecida, mientras que decantarse por el envío a vertedero podría implicar un mejor desempeño ambiental pero supondría problemas de ocupación de terreno y desventajas socioeconómicas. Por otra parte, también se caracterizó ambientalmente la valorización de los restos orgánicos de mejillón para producir paté. A raíz de esta caracterización, se llegó a la recomendación de mejoras centradas en la proporción de los ingredientes (minimización del consumo de aceite, leche en polvo, aromas y especias) así como en la optimización logística (transporte del paté) y energética (energía calorífica). La implementación de los sistemas de valorización de la concha y los restos orgánicos de mejillón dentro del caso de estudio general del mejillón reveló que estos sistemas de gestión sí que contribuyen a los impactos ambientales potenciales, pero con unos valores de caracterización inferiores a los correspondientes al cultivo y procesado de mejillón. Aunque la acuicultura extensiva del mejillón domina la acuicultura gallega, la acuicultura intensiva de peces marinos también goza de un papel relevante, con niveles de producción cercanos a las seis mil toneladas anuales. La acuicultura del rodaballo es responsable del 95% de la producción y facturación vinculadas a la acuicultura intensiva gallega. Así, el cultivo de rodaballo en Galicia supone más del 25% de la facturación acuícola autonómica, y proporciona alrededor del 90% de la producción española de rodaballo de acuicultura. Los capítulos 6 y 7 abordan el ACV de la acuicultura intensiva del rodaballo. Desde un punto de vista ambiental, se sabe que los piensos de uso acuícola constituyen un aspecto clave en cuanto a su contribución a los impactos ambientales potenciales. Por ello, el Capítulo 6 se basa en llevar a cabo un ACV para la producción de piensos destinados a acuicultura, abarcando tanto piensos para acuicultura intensiva
Annex I vi marina como piensos para acuicultura intensiva continental. La formulación de los piensos resultó ser el foco donde centrar las acciones de mejora. Por lo tanto, los productores de piensos deberían evaluar el empleo de nuevos ingredientes o la utilización de diferentes proporciones en su formulación. El desarrollo de un ACV detallado para los piensos acuícolas marinos permitió su implementación en el seno del ACV para el cultivo y consumo de rodaballo, que fue el objeto de estudio del Capítulo 7. La caracterización ambiental de la acuicultura gallega de rodaballo condujo a la identificación del consumo eléctrico en los criaderos de rodaballo como el principal punto crítico, por delante del consumo de piensos y diesel en las plantas de engorde. Además, se estableció una comparación aproximada entre acuicultura intensiva y acuicultura extensiva tomando como referentes el cultivo de rodaballo y mejillón, respectivamente; y adoptando como unidad funcional un mismo aporte proteínico. Consecuentemente, de manera general, el sector acuícola extensivo (mejillón) mostró un peor comportamiento ambiental que el sector acuícola intensivo (rodaballo). La aplicación del ACV a los sectores acuícolas del mejillón y rodaballo en Galicia demostró la capacidad de esta herramienta para proporcionar transparencia y trazabilidad a lo largo de toda la cadena comercial de mejillones y rodaballo. No obstante, esta tesis doctoral no sólo aplica la metodología del ACV, sino que también desarrolla y discute nuevas tendencias en el empleo del ACV, como son la aplicación conjunta de ACV y DEA, y la evaluación de huellas de carbono (CF). El DEA es una metodología empleada para cuantificar la eficiencia productiva de múltiples entidades similares. Para llevar a cabo un DEA, deben conocerse los datos de las principales entradas y salidas de cada una de las entidades. A partir de estos datos, esta herramienta formula y resuelve un modelo de optimización que facilita el benchmarking del desempeño operacional de cada entidad evaluada. El DEA discrimina los puntos operacionalmente ineficientes y propone mejoras tecnológicamente plausibles bajo la perspectiva de una actuación operacional eficiente. Por otra parte, los impactos ambientales dependen de la eficiencia con la que se ejecutan las operaciones. En el caso de disponer de los datos de inventario del ciclo de vida para múltiples instalaciones similares, entonces podría realizarse el benchmarking del desempeño operacional de cada instalación mediante DEA. Los capítulos 8 y 9 desarrollan el uso sinérgico de ACV y DEA como un enfoque metodológico que liga la eficiencia operacional y
Resumen vii los impactos ambientales. En particular, el Capítulo 8 propone el método ACV+DEA de cinco pasos como una metodología que aglutina el benchmarking operacional, la verificación de ecoeficiencia y la evaluación de los impactos ambientales potenciales. Este método se aplicó a una amplia muestra de bateas de mejillón a fin de demostrar su aplicabilidad y utilidad. Consecuentemente, se detectaron las bateas operacionalmente ineficientes y se propusieron sus correspondientes valores objetivo a nivel operacional. El método ACV+DEA de cinco pasos demostró la dependencia de los impactos ambientales con respecto al desempeño operacional, y favoreció la cuantificación de los beneficios potenciales dentro del marco conceptual de la ecoeficiencia. La aplicación conjunta ACV+DEA permite conjugar las fortalezas y minimizar las debilidades de ambas metodologías de manera que se logra un efecto sinérgico a la vez que se mantiene el carácter cuantitativo. Los métodos ACV+DEA presentan las ventajas de evitar el uso de inventarios promedio (eludiendo, por lo tanto, las desviaciones estándar asociadas) y de añadir una dimensión económica (operacional) al análisis ambiental. Estas ventajas se consiguen mediante la aplicación del método ACV+DEA de cinco pasos, pero también se obtienen al aplicar el método ACV+DEA de tres pasos desarrollado en el Capítulo 9. Este segundo enfoque de tres pasos permite determinar la eficiencia ambiental así como estimar directamente los impactos ambientales potenciales objetivo. Su aplicabilidad fue también demostrada en el caso de las bateas de mejillón. Así, se identificaron las bateas operacional y ambientalmente ineficientes, y se propusieron directamente las mejoras plausibles tanto en los consumos operacionales como en los impactos ambientales potenciales. Los dos métodos ACV+DEA planteados pueden considerarse de aplicación general para cualquier estudio de ACV siempre y cuando se disponga de datos para múltiples entidades similares. Por último, la creciente concienciación acerca del cambio climático como un problema de carácter global ha llevado a las grandes empresas a solicitar un procedimiento estandarizado para la medición y comunicación de las emisiones de efecto invernadero ligadas a los productos destinados al consumidor. En este contexto, el CF se ha erigido como la herramienta de aplicación para la evaluación de la huella de carbono de productos. Como se discute en el Capítulo 10, esta herramienta resulta de utilidad tanto para las compañías a lo largo de la cadena del producto como para los legisladores.
Annex I viii El CF implica la estimación de la cantidad global de las emisiones de efecto invernadero vinculadas a un producto (bien o servicio) a lo largo de su cadena de abastecimiento, incluyendo su uso y disposición final. Por lo tanto, el término huella de carbono se refiere a las emisiones de efecto invernadero de un producto a través de su ciclo de vida, abarcando tanto las materias primas como la producción, distribución, uso por parte del consumidor y la disposición final/reciclaje. Como gases de efecto invernadero se incluyen el dióxido de carbono, el metano y el óxido nitroso, junto con familias de gases que comprenden los hidrofluorocarbonos y los perfluorocarbonos. No obstante, el CF no debería entenderse como un simple ACV restringido a la categoría de impacto del calentamiento global dado que su reciente auge está promoviendo la construcción de un marco metodológico sólido que garantice el poder de comparación y comunicación. A este respecto, la especificación PAS 2050 proporciona un método de aplicación general para el CF de un producto cuya aceptación se prevé amplia. El Capítulo 10 utiliza el caso de estudio del mejillón para ejemplificar y discutir la implementación del CF para un producto típico de mejillón en conserva de acuerdo con las pautas definidas por la especificación PAS 2050. A lo largo de la evaluación de la correspondiente huella de carbono, se identificaron las fortalezas y debilidades principales de este enfoque, proporcionando a la vez un punto de partida para que los procesadores de mejillón y los legisladores se beneficien de las ventajas que conlleva la utilización responsable del CF. Así, el CF demostró ser una herramienta útil para la evaluación interna de las emisiones de efecto invernadero a lo largo del ciclo de vida del producto. Además, su aplicación condujo a la identificación de puntos susceptibles de mejora. Por lo tanto, el CF se presenta como un interesante apoyo para la toma de decisiones en el seno de las compañías. Sin embargo, es cierto que el CF aporta una visión limitada del desempeño ambiental de un producto debido a que sólo se evalúa una única categoría de impacto (el calentamiento global). Mientras que esto constituye un inconveniente importante, la gran fortaleza del CF radica en el uso de un enfoque de ciclo de vida y en su creciente popularidad. Esto hace posible la elaboración de políticas que promuevan la implementación de estrategias de CF y sirvan así de vehículo provisional hacia un marco político integral para la evaluación ambiental de productos en base a su ciclo de vida.
Resumo ix Annex II Resumo O sector pesqueiro galego é o máis importante de España. A súa facturación económica superou os mil millóns de euros no 2007, aportando máis do 10% do PIB galego. No marco do sector pesqueiro, existe unha actividade na que Galicia preséntase como líder a nivel nacional. Trátase da acuicultura galega, que pode ser entendida como un sector en si mesmo e que proporciona máis do 80% da produción acuícola española. Tradicionalmente distínguense dous grandes tipos de acuicultura. Por unha parte, atópase a acuicultura extensiva, que consiste nun cultivo dirixido principalmente a moluscos e que non require de alimentación artificial. Por outra parte, a acuicultura intensiva preséntase como un método de cultivo de peces mariños ou continentais que esixe alimentación externa. Nesta tese de doutoramento, avalíase ambientalmente o sector acuícola en base a dúas especies de referencia na acuicultura extensiva e intensiva tanto galega como española. Trátase do sector mexilloneiro galego como representante da acuicultura extensiva, e do sector acuícola galego do rodaballo como estandarte da acuicultura intensiva. A ferramenta empregada para a avaliación ambiental dos sectores acuícolas de mexillón e rodaballo é a Análise do Ciclo de Vida (ACV polas súas siglas en galego/castelán, ou LCA polas súas siglas en inglés). O sendeiro cara o desenvolvemento sostible no sector alimentario require a modificación dos patróns operacionais e ambientais actuais. Neste respecto, precísanse importantes reducións nos niveis de consumo de materia e enerxía, e asemade necesítase a mitigación do impacto ambiental. A sostibilidade ambiental consiste na capacidade de mante-las características de valor do medio físico. As ferramentas de xestión ambiental desenvolvéronse para axudar ás compañías á hora de controlar, mellorar e xestionar axeitadamente o seu desempeño ambiental, así como para colaborar na integración dos aspectos ambientais, económicos e sociais. A gran variedade de ferramentas ambientais fai posible a implementación,
Annex II x no seo do entramado empresarial, de estratexias de ecoeficiencia, do enfoque de ciclo de vida e de sistemas de xestión ambiental. En concreto, a ACV é unha técnica para a avaliación dos impactos ambientais potenciais asociados a un produto (ben ou servizo). Para elo, recompílase un inventario das principais entradas e saídas para un determinado sistema de produto, e avalíanse os impactos ambientais potenciais ligados a esas entradas e saídas. A ACV adopta unha perspectiva do berce ata a tumba, analizando os impactos dun produto ó longo de todo o seu ciclo de vida, é dicir, dende a adquisición das materias primas (o berce), pasando pola súa produción e uso, ata a súa disposición final (a tumba). Un dos sectores onde a ACV atópase amplamente implantada é o sector agroalimentario. Sen embargo, mentres a ACV en agricultura áchase bastante ben establecida, a utilización desta ferramenta para a avaliación de sistemas produtivos de alimentos mariños constitúe un fenómeno máis recente. Polo tanto, esta tese contribúe a amplia-lo número de especies acuáticas estudadas baixo un enfoque de ACV mediante a avaliación ambiental dos sectores acuícolas galegos do mexillón ( Mytilus galloprovincialis ) e do rodaballo ( Scophthalmus maximus ), identificando os seus puntos ambientalmente críticos e propondo potenciais de mellora. Máis aló da aplicación da metodoloxía de ACV ó sector acuícola, esta tese tamén desenvolve novas tendencias no emprego da ACV, concretamente afonda nos potenciais da aplicación conxunta de ACV e Análise por Envoltura de Datos (DEA polas súas siglas inglesas), e na implementación de estratexias de avaliación da pegada de carbono (CF polas súas siglas en inglés). A tese divídese en once capítulos recollidos en cinco seccións. A primeira sección abrangue os dous primeiros capítulos, nos que se contextualiza o estudo mediante a introdución do sector acuícola e das principais ferramentas de xestión empregadas (ACV, DEA e CF). A segunda sección céntrase na aplicación da ACV ó sector mexilloneiro galego. Inclúese non só a análise do cultivo de mexillón (Capítulo 3) senón tamén a avaliación do seu procesado e consumo (Capítulo 4), e do tratamento de residuos específicos do sector mexilloneiro (Capítulo 5). Consecuentemente, grazas á ACV acádase unha completa avaliación ambiental dos tres produtos
Resumo xi clásicos de mexillón: mexillón fresco, mexillón en conserva e mexillón conxelado. A terceira sección comprende a avaliación mediante ACV do sector acuícola do rodaballo en Galicia. Primeiramente, lévase a cabo un estudo de ACV para a produción de pensos de acuicultura (Capítulo 6) xa que é sabido que estes pensos resultan ser un elemento clave no comportamento ambiental das plantas acuícolas. Tras elo, o Capítulo 7 integra a ACV dos pensos mariños no caso de estudo do cultivo e consumo de rodaballo. A cuarta sección resérvase ó desenvolvemento e aplicación de metodoloxías intimamente ligadas á ACV. Así, abórdase o uso conxunto de ACV e DEA, mostrándose ademais a súa aplicación no caso da miticultura (é dicir, no cultivo de mexillón) baixo dúas perspectivas diferentes: eficiencia operacional (Capítulo 8) e eficiencia ambiental (Capítulo 9). Por outra parte, o Capítulo 10 exemplifica o cálculo da pegada de carbono empregando para elo un produto típico de mexillón en conserva e as pautas propostas pola especificación PAS 2050, que estase a consolidar como metodoloxía de referencia para a avaliación de pegadas de carbono. A quinta sección componse dun único capítulo (Capítulo 11) onde se recollen as conclusións xerais derivadas desta tese de doutoramento. Os mexillóns son o produto estrela da acuicultura galega. Este molusco bivalvo cultívase en bateas segundo un procedemento acuícola extensivo que require un mínimo control por parte do cultivador e que non precisa de aporte externo de nutrientes nin da participación durante o proceso reprodutivo. As bateas galegas producen o 98% dos mexillóns cultivados en España. O Capítulo 3 recolle a primeira ACV levada a cabo para a fase de cultivo de mexillón. Con este fin, estudáronse as principais áreas produtivas galegas. Os datos de inventario obtivéronse de entrevistas e enquisas realizadas para un conxunto de embarcacións que conta coa produción de máis de sete mil toneladas de mexillón. A caracterización ambiental incluíu as seguintes categorías de impacto: esgotamento dos recursos abióticos, quentamento global, esgotamento da capa de ozono, toxicidade humana, ecotoxicidade (mariña, de auga doce e terrestre), formación de oxidantes fotoquímicos, acidificación e eutrofización. Os resultados desta caracterización revelaron a importancia de considerar non só os aspectos operacionais, senón tamén os bens capitais (instalacións e equipos). O consumo
Annex II xii de diesel para a operación da embarcación resultou se-lo principal motivo dos impactos ambientais potenciais, xunto co uso de enerxía e ferro para os bens capitais. Non obstante, necesitaríase un estudo máis pormenorizado dos bens capitais. O cultivo de mexillón dá lugar a un complexo sectorial que non só inclúe as actividades acuícolas senón tamén un entramado de actividades ligadas ó procesado do mexillón. A este respecto, ademais do subsector de cultivo de mexillón, pódense distinguir tres subsectores en función dos centros onde ten lugar a transformación do mexillón: (i) subsector das estacións depuradoras de moluscos, (ii) subsector das empresas conserveiras, e (iii) subsector dos cocedoiros de mexillón e empresas conserveiras parciais (é dicir, conserveiras que reciben a vianda de mexillón xa cocida). O Capítulo 4 inclúe a avaliación mediante ACV do procesado e consumo de mexillón. A elaboración e uso de inventarios exhaustivos conduciu á caracterización ambiental do sector mexilloneiro en termos da contribución de cada un dos subsectores ós impactos ambientais potenciais. Neste sentido, o subsector das estacións depuradoras de moluscos (responsables da provisión de mexillón fresco) contou coas maiores contribucións, claramente por diante do subsector de cultivo. Os subsectores das empresas conserveiras e dos cocedoiros de mexillón presentaron unhas contribucións moito menores. Os potenciais de mellora propostos destacaron a necesidade de minimiza-lo consumo de enerxía eléctrica nas estacións depuradoras de moluscos. Por outra parte, levouse a cabo unha ACV comparativa coa finalidade de contrasta-lo perfil ambiental dos tres principais produtos de mexillón. Así, esta análise concluíu que os mexillóns frescos comportan un perfil ambiental máis desfavorable cando son comparados cos mexillóns en conserva e cos mexillóns conxelados. O procesado de mexillón orixina unha serie de residuos específicos da industria mexilloneira. Entre estes residuos, destacan a cuncha de mexillón e os restos orgánicos de mexillón. O Capítulo 5 trata a xestión tanto da cuncha coma dos restos orgánicos de mexillón dende un enfoque de ACV. Por unha parte, procedeuse á caracterización ambiental da valorización da cuncha de mexillón para producir carbonato cálcico. Consecuentemente, o consumo de propano e enerxía eléctrica, a xestión do lodo e as cinsas, o transporte e as emisións atmosféricas foron identificados como os puntos ambientalmente críticos onde deberían centrarse os potenciais de mellora. Neste sentido, realizouse a avaliación
Resumo xiii ambiental dun escenario futuro para estima-las consecuencias ambientais potenciais no caso de adoptar tres medidas concretas: uso de glicerina en vez de propano, consideración das cinsas de proceso como un produto e non como un residuo, e valorización do lodo. A ACV amosou que tal escenario futuro podería supor un peor desempeño ambiental con respecto á situación actual, a menos que soamente se adoptasen as medidas concernentes ás cinsas e ó lodo. Ademais, avaliouse ambientalmente a conveniencia da valorización da cuncha de mexillón en comparación con outras alternativas para a xestión de residuos (vertedoiro e incineración). A incineración resultou se-la opción menos favorecida, mentres que optar polo envío a vertedoiro podería implicar un mellor desempeño ambiental pero suporía problemas de ocupación de terreo e desvantaxes socioeconómicas. Por outra parte, caracterizouse tamén a valorización dos restos orgánicos de mexillón para producir paté. A raíz desta caracterización, chegouse á recomendación de melloras centradas na proporción dos ingredientes (minimización do consumo de aceite, leite en po, aromas e especias) así como na optimización loxística (transporte do paté) e enerxética (enerxía calorífica). A implementación dos sistemas de valorización das cunchas e dos restos de mexillón dentro do caso de estudio xeral do mexillón revelou que estes sistemas de xestión si que contribúen ós impactos ambientais potenciais, pero cuns valores de caracterización inferiores ós correspondentes ó cultivo e ó procesado de mexillón. Aínda que a acuicultura extensiva do mexillón domina a acuicultura galega, a acuicultura intensiva de peces mariños tamén goza dun papel relevante, con niveis de produción próximos ás seis mil toneladas anuais. A acuicultura de rodaballo é responsable do 95% da produción e facturación vinculadas á acuicultura intensiva galega. Así, o cultivo de rodaballo en Galicia supón máis do 25% da facturación económica acuícola autonómica, e proporciona arredor do 90% da produción española de rodaballo de acuicultura. Os capítulos 6 e 7 abordan a ACV da acuicultura intensiva de rodaballo. Dende un punto de vista ambiental, é sabido que os pensos de uso acuícola constitúen un aspecto clave en canto á súa contribución ós impactos ambientais potenciais. Por elo, o Capítulo 6 baséase en levar a cabo unha ACV para a produción de pensos destinados a acuicultura, abarcando tanto pensos para acuicultura intensiva mariña coma pensos para acuicultura intensiva continental. A formulación dos pensos resultou se-lo foco onde centra-las accións de mellora. Por tanto, os produtores de pensos deberían
Annex III xx Courses (cont.) 11. “Desarrollo ambiental sostenible en Austria” . Dr. Eng. Karl E. Lorber (Institute for Sustainable Waste Management and Technology, University of Leoben). School of Engineering. University of Santiago de Compostela (Spain). 13-14 September 2007 12. “Tecnología de alimentos: un enfoque multidisciplinario a su problemática presente y futura” . Prof. Dr. J. Antonio Torres (Food Process Engineering Group, Oregon State University). School of Engineering. University of Santiago de Compostela (Spain). 27 September 2007 13. “II Xornadas sobre Sustentabilidade no Sector Pesqueiro Galego: Retos da Miticultura” . Advanced Studies Centre (CEA). University of Santiago de Compostela (Spain). 26 October 2007 14. “Modelos de calidad del aire” . Prof. Ana Isabel Miranda (University of Aveiro). School of Engineering. University of Santiago de Compostela (Spain). 21-23 January 2008 15. “Inventarios de emisiones atmosféricas” . Dr. Carlos Borrego (University of Aveiro). School of Engineering. University of Santiago de Compostela (Spain). 11-13 June 2008 16. “Technical workshop on carbon footprint labelling of food products: Carbon footprint analysis and management” . Centre for Environmental Strategy (CES). University of Surrey, Guildford (UK). 20-22 October 2008 17. “VII Reunión de la Red Temática de ACV” . School of Engineering. University of Santiago de Compostela (Spain). 7-8 June 2009 18. “Biorremediación de aguas ricas en arsénico y biorremediación de aguas de drenajes ácidos de minas” . Prof. Dr. Jim Field and Prof. Dr. Reyes Sierra (University of Arizona). School of Engineering. University of Santiago de Compostela (Spain). 21 July 2009
Curriculum Vitae xxi Conferences 1. “The application and assessment of Control Station software for education in chemical engineering”. P.M. Bello, D. Iribarren , M.C. Barros, J.A. Souto. International Technology, Education and Development Conference, Valencia (Spain), 7-9 March 2007. INTED2007 Proceedings (ISBN: 84-611-4517-8). IATED, 2007 2. “Practicals development for the teaching of Instrumentation and Control of Chemical Processes in Chemical Engineering Degree”. P.M. Bello, D. Iribarren , J.A. Souto, M. González. International Technology, Education and Development Conference, Valencia (Spain), 3-5 March 2008. INTED2008 Abstracts Book (ISBN: 978-84-612-0192-1) & INTED2008 Proceedings (ISBN: 978-84-612- 0190-7). IATED, 2008 3. “Combined use of process simulator and EMFA software for plant environmental design in chemical engineering degree”. D. Iribarren , P.M. Bello. International Technology, Education and Development Conference, Valencia (Spain), 3-5 March 2008. INTED2008 Abstracts Book (ISBN: 978-84-612-0192- 1) & INTED2008 Proceedings (ISBN: 978-84-612-0190-7). IATED, 2008 4. “Binomio eficiencia operacional-impactos ambientales en miticultura”. D. Iribarren , M.T. Moreira, G. Feijoo. Congreso Medio Rural y Cambio Climático, A Coruña (Spain), 26 March 2009 5. “Linking fuel consumption and eco-efficiency in fishing vessels. A brief case study on selected Galician fisheries”. I. Vázquez-Rowe, D. Iribarren , A. Hospido, M.T. Moreira, G. Feijoo. 1 st International Symposium on Fishing Vessel Energy Efficiency, Vigo (Spain), 18-20 May 2010 6. “A double perspective on the joint implementation of Life Cycle Assessment and Data Envelopment Analysis”. I. Vázquez-Rowe, D. Iribarren , M.T. Moreira, G. Feijoo. SETAC Europe 20 th Annual Meeting, Seville (Spain), 23-27 May 2010 7. “Estimating the carbon footprint of the Galician fishing sector (NW Spain)”. D. Iribarren , I. Vázquez-Rowe, A. Hospido, M.T. Moreira, G. Feijoo. 7 th International Conference on Life Cycle Assessment in the Agri-Food Sector, Bari (Italy), 22-24 September 2010
Annex III xxii Conferences (cont.) 8. “The importance of operational inputs in the environmental assessment of seafood. A case study with Galician fisheries (NW Spain)”. I. Vázquez-Rowe, D. Iribarren , A. Hospido, M.T. Moreira, G. Feijoo. 7 th International Conference on Life Cycle Assessment in the Agri-Food Sector, Bari (Italy), 22-24 September 2010 Publications Published 1. “The link between operational efficiency and environmental impacts. A joint application of Life Cycle Assessment and Data Envelopment Analysis”. S. Lozano, D. Iribarren , M.T. Moreira, G. Feijoo. Science of the Total Environment 407: 1744-1754 (2009) 2. “Revisiting the Life Cycle Assessment of mussels from a sectorial perspective”. D. Iribarren , M.T. Moreira, G. Feijoo. Journal of Cleaner Production 18: 101-111 (2010) 3. “Combined application of Life Cycle Assessment and Data Envelopment Analysis as a methodological approach for the assessment of fisheries”. I. Vázquez-Rowe, D. Iribarren , M.T. Moreira, G. Feijoo. The International Journal of Life Cycle Assessment 15 (3): 272-283 (2010) 4. “Implementing by-product management into the Life Cycle Assessment of the mussel sector”. D. Iribarren , M.T. Moreira, G. Feijoo. Resources, Conservation and Recycling. DOI: 10.1016/j.resconrec.2010.03.017 (2010) 5. “Environmental impact efficiency in mussel cultivation”. S. Lozano, D. Iribarren , M.T. Moreira, G. Feijoo. Resources, Conservation and Recycling. DOI: 10.1016/j.resconrec.2010.04.004 (2010) 6. “Carbon footprint of canned mussels from a business-to-consumer approach. A starting point for mussel processors and policy makers”. D. Iribarren , A. Hospido, M.T. Moreira, G. Feijoo. Environmental Science & Policy. DOI: 10.1016/j.envsci.2010.05.003 (2010)
Curriculum Vitae xxiii Publications (cont.) 7. “Life Cycle Assessment of mussel culture”. D. Iribarren , M.T. Moreira, G. Feijoo. In: “Mussels: Anatomy, Habitat and Environmental Impact”, Nova Science Publishers, New York, USA, in press (2010) In review 1. “Life Cycle Assessment of fresh and canned mussel processing and consumption in Galicia (NW Spain)”. D. Iribarren , M.T. Moreira, G. Feijoo. Resources, Conservation and Recycling 2. “Life Cycle Assessment of aquaculture feed and application within the turbot sector”. D. Iribarren , M.T. Moreira, G. Feijoo. Journal of Cleaner Production 3. “The link between fuel consumption and eco-efficiency in fishing vessels. A case study on selected Galician fleets”. I. Vázquez-Rowe, D. Iribarren , A. Hospido, M.T. Moreira, G. Feijoo. Journal of Industrial Ecology 4. “Estimation of the carbon footprint of the Galician fishing activity (NW Spain)”. D. Iribarren , I. Vázquez-Rowe, A. Hospido, M.T. Moreira, G. Feijoo. Science of the Total Environment Other interesting data Master in Prevention of Labour Risks, Quality and Environmental Management . Centro de Iniciativas Profesionales. Santiago de Compostela (Spain). October 2007-June 2008 Contract of employment . Institute of Technology. University of Santiago de Compostela (Spain). June-December 2006 Award for one of the five best academic records in Chemical Engineering . School of Engineering. University of Santiago de Compostela (Spain) Special award in Chemical Engineering degree . University of Santiago de Compostela (Spain)
Acronyms xxv Acronyms Acronym Concept Acronym Concept ADP Abiotic Depletion Potential HTP Human Toxicity Potential AP Acidification Potential LCA Life Cycle Assessment CF Carbon Footprinting LCI Life Cycle Inventory CRS Constant Returns to Scale LCIA Life Cycle Impact Assessment DEA Data Envelopment Analysis LP Linear Program DMU Decision Making Unit METP Marine aquatic Eco-Toxicity Potential EP Eutrophication Potential ODP Ozone layer Depletion Potential ERM Enhanced Russell graph Measure POFP Photochemical Oxidant Formation Potential FETP Fresh water aquatic Eco-Toxicity Potential PPS Production Possibility Set FU Functional Unit SBM Slacks Based Measure GHG GreenHouse Gas TETP Terrestrial Eco-Toxicity Potential GWP Global Warming Potential VRS Variable Returns to Scale
Acknowledgements xxvii Acknowledgements Diego Iribarren wishes to thank the Spanish Ministry of Education (grant reference: AP2006-03904) and the Galician Government (project reference: PGIDIT04TAL269003PR; grant reference: 2006/000195-0) for financial support. The author would like to thank G. Feijoo and M.T. Moreira for the supervision of this doctoral thesis, as well as the Group of Environmental Biotechnology and Engineering of the University of Santiago de Compostela for all the support provided.