A Comparative Techno-economic Analysis of Hydrogen Production Processes from Locally Available Resources in Nigeria

© STM Journals 2024. All Rights Reserved 29 ISSN: 2230-7982 (Online) ISSN: 2321-5186 (Print) Volume 15, Issue 1, 2024 January—April DOI (Journal): 10.37591/JoAEST STM JOURNALS Journal of Alternate Energy Sources & Technologies https://journals.stmjournals.com/joaest Research JoAEST A Comparative Techno-economic Analysis of Hydrogen Production Processes from Locally Available Resources in Nigeria Ayomiposi Moses1,*, Ayoade Kuye2, Akachidike Kanu3, Akuma Oji4 HIGHLIGHTS  Techno-economic analysis of hydrogen production-based process engineering and lifecycle cost modeling and simulation.  Typical Nigerian sweet natural gas composition was used for the SMR processes.  SMR, SMR+CC, and PEM processes were simulated and compared.  SMR process is significantly cheaper due to abundant natural gas feedstock in the Niger Delta region of the country.  Cost of PEM process appears considerably cheaper in locations with high solar radiation, notably in Northeastern region of the country. Abstract In this work we report result of techno-economic analyses of three hydrogen production pathways - Steam Methane Reforming (SMR), SMR with Carbon Capture (SMR+CC) and Proton Exchange Membrane electrolysis (PEM) – using integrated process-cost simulation-estimation methodologies. Process modeling and simulation is performed with Aspen Hysys® and Aspen Plus® (V10). Cost modeling and estimation is based on full lifecycle cost of production using the Levelized Cost of Hydrogen (LCOH) approach. Feedstock natural gas and renewable power for the SMR and PEM processes respectively are based on local sources and environmental conditions in Nigeria. The basis used is a hydrogen production of 36kg/hr (400Nm3/hr). Results show that the SMR process has specific CO2 emissions of 4.9 kg CO2/kg H2. A 90% capture efficiency is used for the SMR+CC process, whereas zero GHG emissions is assumed for the PEM processes. The yield of hydrogen in SMR, SMR+CC and PEM processes are 74%, 93% and 99% respectively. The Levelized Cost of Hydrogen (LCOH) for SMR, SMR+CC and PEM processes are $1.44/𝑘𝑔𝐻2,$2.26/𝑘𝑔𝐻2,$4.67/𝑘𝑔𝐻2 respectively. Keywords: Hydrogen, Steam Methane Reforming, Electrolysis, Levelized Cost of Hydrogen INTRODUCTION The huge population growth and economic development taking place all over the world are the main drivers of rising energy demand. The industrial transformation in any nation depends heavily on energy generation [1]. Due to its claims of providing carbonfree solutions, hydrogen is becoming more and more well-known as a novel energy source and potential *Author for Correspondence Ayomiposi Moses E-mail: [email protected] 1,2Students, Department of Chemical Engineering, University of Port Harcourt. Abuja campus, university of local government, Port-Harcourt 500272, Rivers, Nigeria 3,4Professor and Scientist, Department of Chemical Engineering , Center for Gas, Refining and Petrochemical Engineering, University of Port Harcourt, Abuja campus, university of local government, PortHarcourt 500272, Rivers, Nigeria Received Date: May 09, 2024 Accepted Date: May 18, 2024 Published Date: May 28, 2024 Citation: Ayomiposi Moses, Ayoade Kuye, Akachidike Kanu, Akuma Oji. A Comparative Techno-Economic Analysis of Hydrogen Production Processes from Locally Available Resources in Nigeria. Journal of Alternate Energy Sources & Technologies. 2024; 15(1): 29–46p. A Comparative Techno-economic Analysis of Hydrogen Production Moses et al. © STM Journals 2024. All Rights Reserved 30 future fuel [2, 3, 4]. Hydrogen is the periodic table's first element. The element has an atomic number of 1, making it the lightest one. A hydrogen gas molecule has the chemical formula H2 and a molecular weight of 2 g/mol. It is an effective reducing agent. It has a very low volumetric density of 0.0899 kg/m3 for its gaseous form at 20oC and 1 bar of pressure and 70.8 kg/m3 for its liquid form at -253oC and 1 bar of pressure, respectively [5]. Its lower heating value, or LHV, is equivalent to 120 MJ/kg, and its higher heating value, or HHV, is equal to 142 MJ/kg, giving it a very high gravimetric energy density. For instance, hydrogen has a gravimetric energy density that is around three times larger than that of gasoline [6]. Hydrogen is about 9 times lighter than natural gas. It also has a higher energy content than natural gas as shown in Table 1 where it is clearly seen that the energy content in 1 kg of hydrogen (142 MJ) exceeds double that of natural gas (55 MJ). This makes hydrogen a suitable alternative to natural gas [7]. Unlike natural gas, hydrogen is an energy carrier that has water has its only exhaust product upon conversion to energy. This makes hydrogen more environmentally friendly and highly beneficial than natural gas [8]. A summary of the physicochemical properties of hydrogen and natural gas is presented in Table 1. Several literatures that discuss different facets of hydrogen production have been released in recent years. There are still more things to discover and thoroughly look into by way of research. Although the production of hydrogen is a technological advancement, there are still significant uncertainties and challenges that prevent its full deployment [1]. In addition, because hydrogen generation is an area that is continually growing, current advancements, future development requirements, and projections must be examined and discussed. Steam Methane Reforming (SMR) is an advanced and well-established method of producing hydrogen. Hydrogen can be produced thermally from methane (CH4) in natural gas by steam reforming of methane which takes place as a result of its reaction with steam [7-9]. Practically, processing of gas mixtures involving CO, CO2, and CH4 is necessary. Only after purification is high-purity hydrogen produced by the reaction of carbon monoxide with steam over a catalyst, which also produces additional amounts of hydrogen and carbon dioxide. The majority of the time, CO2 vents into the atmosphere, but there are a variety of ways to capture it for sequestration [10]. Water Electrolysis takes place when water is separated into oxygen and hydrogen via electrolysis. Because water is widely available compared to hydrocarbons and because electrolysis uses water to make hydrogen, it is of interest as a prospective source. The electrolyzer is where the reaction that splits water happens [11]. Different electrolyzer sizes exist. For small-scale hydrogen production, small-sized electrolyzers are suitable. Large sizes are ideal for centralized production facilities that might be directly connected to any type of electricity production (renewable or not) [11]. An electrolyte separates the anode and cathode in electrolyzers, just like it does in fuel cells. Because different electrolyzers are constructed with various types of electrolyte material, their functions are slightly different from one another [10]. Technology for electrolysis has advanced and is readily available. Proton exchange membrane (PEM), alkaline water (AEL), and solid oxide (SOEC) electrolyzers are the three primary types of electrolyzers used to produce hydrogen [12]. Table 1. Physico-chemical properties of Hydrogen and Natural Gas. S/N Property Unit H2 Natural Gas 1 Molecular Weight kg/kmol 2.016 18.82 2 Density kg/m3 (at P=1atm, T=0oC) 0.09 0.7 – 0.9 3 Boiling Point oC -253 -161.6 4 Melting Point oC 259 -182.5 5 Higher Heating Value (HHV) MJ/kg 142 55 6 Lower Heating Value (LHV) MJ/kg 120 42 Journal of Alternate Energy Sources & Technologies Volume 15, Issue 1 ISSN: 2230-7982 (Online), ISSN: 2321-5186 (Print) © STM Journals 2024. All Rights Reserved 31 7 Auto Ignition Temperature oC 585 650 In Proton Exchange Membrane Electrolysis (PEM), water arrives at the anode side, where the molecules it contains break down into hydrogen ions, oxygen ions, and electrons [13]. Here, the oxidation reaction results in oxygen gas production [14]. Due to the membrane's ability to conduct proton, hydrogen ions can move across it. After passing through the membrane and entering the cathode, the hydrogen ion undergoes reduction and generates hydrogen gas [14]. The three major components of PEM are the stack, cathode, and anode. The primary element of PEM is the stack, where the primary water reaction takes place to produce the necessary hydrogen. The stack consists of a reactor and a separator together. In the PEM, oxygen gas is produced in the anodic portion whereas hydrogen gas is created in the cathode section [15]. The PEM process is preferred to AEL process because it has fast response ramp-up and ramp-down capacity. It also has an extensive dynamic operating range of 0-100% which makes it ideal for the production of hydrogen using excess renewable energy [12]. Depending on the source or process of production, and the by-products of the production process with respect to carbon or carbon compounds produced, hydrogen has been widely distinguished into three main types which are grey, blue and green hydrogen. Grey hydrogen is extracted from fossil fuels like coal or methane. This results in a significant amount of CO2 produced that is then discharged into the atmosphere without being put to any other use. This method is the most widely used [16]. Blue hydrogen is produced from sources and procedures that discharge CO2 into the atmosphere, but it is then caught and stored (and occasionally employed in additional procedures). We are referring to carbon capture and storage (CCS) in this instance. The concept behind blue hydrogen is that most of the GHG emissions from the procedures now used to manufacture hydrogen from fossil fuels might be reduced by coupling them with CCS technologies [16]. By electrolyzing water, green hydrogen is produced solely with electricity generated from renewable sources. Water can be split into hydrogen and oxygen molecules via the electrolysis method. Hydrogen is created with no CO2 emissions because it is based on renewable energy [15]. In a nutshell, a green hydrogen pathway is one that combines water electrolysis and energy production from renewable resources. Today, these three types (i.e. grey, blue and green) of hydrogen are well known, but pink and turquoise hydrogen are also now appearing [16]. Nigeria has an abundance of gas resources; it is believed that her associated gas reserves account for 60% of her total natural gas reserves [17]. Projects to monetize the use and transportation of Nigeria's associated gas and natural gas reserves are now underway. These consist of the LNG (liquefied natural gas), GPL (gas pipeline), GTL (gas to liquids), LPG (liquefied Petroleum Gas), and gas injection project for enhanced oil recovery [18]. LNG is the technology that is most matured in Nigeria. With the ability to monetize over 3000 MMscf/d of natural gas, the Nigerian Liquefied Natural Gas (NLNG) company is taking a more active position in harnessing Nigeria's natural gas [18]. This natural gas can be used as feedstock for hydrogen production in the nation. Nigeria is also blessed with a variety of sustainable conventional and renewable energy sources, including biomass, solar, wind, and hydropower [19, 20, 21]. With an annual average sunshine hour and annual average solar radiation of 6.25 h/day and 5.25 kWh/day, respectively, depending on the region [22], the country's annual daily average solar radiation is 12.6 MJ/m2/day (3.5 kWh/m2/day) in the south and 25.3 MJ/m2/day (7.0 kWh/m2/day) in the far north [21]. In Nigeria, a solar module covering 1% of the country's land area can provide 1,850×103 GWh of solar electricity annually [23]. The six states of Adamawa, Bauchi, Borno, Gombe, Taraba, and Yobe in northeastern Nigeria have very high incidences of solar radiation on their horizontal surfaces, making them highly suitable for large-scale solar photovoltaic (PV) projects [24]. This solar electricity can be deployed to provide renewable energy for PEM hydrogen production plants. Nigeria also has large freshwater resource that can be used as feed for PEM electrolysis process for producing hydrogen [19]. Aspen Plus® and Aspen Hysys®, are process simulators in steady state. They are used to forecast the behavior of a process or a group of unit activities by taking into account their current interrelationships [25]. The mass and energy balances, the phase and chemical equilibria, and the rates of chemical transformation are all determined by the relationships and linkages present in the process. With the aim A Comparative Techno-economic Analysis of Hydrogen Production Moses et al. © STM Journals 2024. All Rights Reserved 32 of enhancing design specifications or raising the profitability and efficiency of a process operation, it is possible to simulate the behavior of current or future plants in this way [25]. The Levelized Cost of Hydrogen (LCOH) is a significant Key Performance Indicator (KPI) that is specific to hydrogen generation. This is determined by dividing the net discounted costs by the amount of hydrogen produced, taking into account the cost of the hydrogen generation process [4]. This indicator focuses on the economic study of hydrogen production [5].The decision-making process for choosing the most sustainable technique is complicated by the abundance of hydrogen production methods available [9]. In order to produce hydrogen, these processes require significant inputs, including capital expense, feedstock expense, and operation and maintenance (O&M) expense. Therefore, it is essential to assess the economic viability of various hydrogen production processes in order to enable decision-makers to select the hydrogen production process with optimal cost of production [26]. The foundation of hydrogen economics is the provision of cost-competitive hydrogen energy of sufficient quality and quantity. In order to determine the optimum hydrogen production method that is also economically viable, it is crucial to analyze the various hydrogen production techniques that are currently in use [27]. A full analysis of the technological constraints of various hydrogen production technologies and their associated economic implications is required due to the continuously growing interest in hydrogen applications. Therefore, this study addresses the problem of determining suitable technology and economically feasible method for hydrogen production to meet up with the ever-increasing energy demand of the world. This study analyses the technical and economic constraints of selected processes of hydrogen production and determines their corresponding estimates of LCOH. It provides a detailed comparative study of the technical and economic aspects of hydrogen production processes. METHODOLOGY Aspen Hysys software was used to simulate the SMR and SMR+CC processes while Aspen Plus software was used to simulate the PEM process. The Aspen Process Economic Analyzer (APEA) tool was used for the cost estimation of each hydrogen production process considered. The estimated cost was used to determine the Levelized Cost of Hydrogen (LCOH) of the three hydrogen production processes. Economic analysis was based on the comparison of the LCOH of the three different hydrogen processes. Steam Methane Reforming without Carbon Capture (SMR) Process Description The SMR process block diagram is shown in Figure 1. The natural gas stream was delivered at an elevated pressure of 40 bar and at temperature of 15oC. The feed NG was preheated and mixed with medium pressure (MP) steam and a steam-to-carbon molar ratio of 2.7 is used to avoid carbon deposition and to ensure a high steam-to-dry gas ratio in the water gas shift (WGS) reactor and preserve the Fe-based catalyst [28]. The gas mixture of steam and NG was fed into a pre-reformer with a nickel catalyst at 450˚C, where higher hydrocarbons are converted to methane and carbon oxides. The carbon monoxide is hydrogenated to methane and water gas equilibrium reaction is established. Here, the reforming and shift reactions reach equilibrium, resulting in some conversion of CH4 [28]. The heat duty in the reformer was reduced with the use of pre-reformer [29-35]. The reforming reactions are presented in Eqns. (1) – (6) while the shift reactions are presented in Eqns. (7) & (8). The reforming and shift reactions are equilibrium reactions represented as follows: Journal of Alternate Energy Sources & Technologies Volume 15, Issue 1 ISSN: 2230-7982 (Online), ISSN: 2321-5186 (Print) © STM Journals 2024. All Rights Reserved 33 Figure 1. Block Diagram of SMR process. 𝐶𝐻4+𝐻2𝑂 ↔𝐶𝑂+3𝐻2 (1) 𝐶2𝐻6+2𝐻2𝑂↔2𝐶𝑂+5𝐻2 (2) 𝐶3𝐻8+3𝐻2𝑂↔3𝐶𝑂+7𝐻2 (3) 𝐶4𝐻10 +4𝐻2𝑂 ↔4𝐶𝑂+9𝐻2 (4) 𝐶5𝐻12 +5𝐻2𝑂 ↔5𝐶𝑂+11𝐻2 (4) 𝐶6𝐻14 +6𝐻2𝑂 ↔6𝐶𝑂+13𝐻2 (5) 𝐶7𝐻16 +7𝐻2𝑂 ↔7𝐶𝑂+15𝐻2 (6) 𝐶𝑂+3𝐻2↔𝐶𝐻4+𝐻2𝑂 (7) 𝐶𝑂+3𝐻2𝑂 ↔𝐶𝑂2+𝐻2 (8) The effluent gases of the pre-reformer were preheated to 620˚C before they were fed into the steam reformer. The reformer tubes were heated to a temperature of 920˚C. The produced syngas and approximately 80% of the methane is converted according to Eqns (1) and (7). The syngas exiting the reformer is cooled in a heat exchanger to 330oC. The cooled syngas is fed to a high temperature (HT) water gas shift (WGS) reactor (commonly carried out with a Fe-based catalyst) where approximately 70% of the CO is converted according to Eqn. (8). This plant has only a HT WGS reactor. The gases were then cooled to ambient temperature and the condensed steam was removed before the Pressure Swing Adsorption (PSA) unit. The PSA was assumed to have a H2 separation efficiency of 90% and a purity of 100%. Process Modeling and Simulation Figure. 2 shows the flow sheet of the SMR plant that was represented by the block diagram in Figure 1 using Aspen Hysys (version 10). A typical Nigerian natural gas with composition sourced from the Nigeria Liquefied Natural Gas (NLNG) company data [18] was used as the feedstock. The model included the steam reforming process. Peng-Robinson equation of state was the base property method for the thermodynamic calculations in Aspen Hysys. In Figure 1, the natural gas stream enters the system at 40 bar, 15˚C. The pre-reformer, reformer and WGS reactor were all modelled as equilibrium reactors (ERV 100, ERV101, and ERV-102 respectively). In the WGS reactor the hydrocarbons were considered as inert. The PSA was modelled as a separator (V-100). It was assumed that there was no pressure drop in the PSA for the separated H2 product gas. Atmospheric pressure is assumed in the furnace. The S/C ratio was set to 2.7 with a manipulator modelled as SET-1 in Aspen Hysys relating the molar flow of steam to the molar flow of carbon from the natural gas feed stream. It was assumed that pressure drop is 1% of the inlet pressure over reactors and no pressure drop across all heat exchangers. A Comparative Techno-economic Analysis of Hydrogen Production Moses et al. © STM Journals 2024. All Rights Reserved 34 Steam Methane Reforming with Carbon Capture (SMR + CC) Process Description Figure 3 shows a simple block diagram of the SMR + CC process. The SMR + CC Process is similar to the SMR process described in section 2.1.1 except that the syngas exiting the reformer is fed into two water gas shift (WGS) reactors. These reactors are the high temperature water gas shift (HT WGS) converter and the low temperature water gas shift (LT WGS) converter. Journal of Alternate Energy Sources & Technologies Volume 15, Issue 1 ISSN: 2230-7982 (Online), ISSN: 2321-5186 (Print) © STM Journals 2024. All Rights Reserved 35 Figure 2. Flow sheet of the SMR Process. Figure 3. Block Diagram of SMR + CC Process. A Comparative Techno-economic Analysis of Hydrogen Production Moses et al. © STM Journals 2024. All Rights Reserved 36 The HT and LT WGS reactors were arranged in series with Fe2O3-Cr2O3 and CuO/ZnO/Al2O3 catalysts, respectively [28]. In the syngas purification unit, CO2 was absorbed by Methyl Di-ethanol amine (MDEA) solution and separated from the hydrogen-rich gas. Process Modeling and Simulation The Aspen HYSYS simulation flowsheets of the SMR+CC process were shown in Figures 4 & 5. The natural gas stream enters the system at 40 bar, 15˚C and was pre-heated in a heater (E-101) before it was mixed with steam. The mixed feed was fed into the pre-reformer. The pre-reformer was modelled as an equilibrium reactor (ERV-100). The exit stream of the pre-reformer was heated by a heater (E102) to a temperature of 600oC before entering the reformer. The reformer was modelled as an equilibrium reactor (ERV-103). The exit stream of the reformer was cooled by a cooler (E-103) before entering the high temperature (HT) CO shift reactor modelled as an equilibrium reactor (ERV-101) where most of the conversion of CO to CO2 takes place. The exit stream of the HT CO shift reactor was cooled in a cooler (E-104) before entering the low temperature (LT) CO shift reactor where equilibrium conversion of CO to CO2 with more unconverted CO from the HT CO shift reactor being converted to CO2. The exit stream of the LT CO shift reactor was cooled in a cooler. The condensed steam from the effluent cooling was removed in a separator (V-100) before the syngas was fed into the amine unit modelled as a CO2 absorber (T-100). Proton Exchange Membrane (PEM) Electrolysis of Water Process Description The PEM process block diagram as shown in Figure 6: The Proton Exchange Membrane (PEM) Electrolysis process involved water splitting which took place in the electrolyzer stack or cell central component which is the membrane-electrode assembly (MEA). Water was pumped through the flow-channels of the bipolar plates in both anode and cathode side to feed the reaction in anode. Water decomposition took place at the anode side [31, 32]. The reaction is shown in Eqn. (9): 2H2O → O2 + 4H+ + 4e− (9) Figure 4. Flowsheet (1) of the SMR+CC process. Figure 5. Flowsheet (2) of the SMR+CC process. MDEA Syngas Purified Gas T-100 Rich Solution Journal of Alternate Energy Sources & Technologies Volume 15, Issue 1 ISSN: 2230-7982 (Online), ISSN: 2321-5186 (Print) © STM Journals 2024. All Rights Reserved 37 Figure 6. Block Diagram of PEM Electrolysis process. Produced H+ protons passed through the membrane structure to cathode where they were reduced to gaseous hydrogen. The reaction is shown in Eqn. (10): 4H+ + 4e− → 2H2 (10) Produced oxygen and hydrogen gases were collected from the backs of the porous transport layers to gas manifolds. Water circulation does not only provide feedstock for the reactions but was also used to extract excess heat resulting from the operation [32, 33]. Process Design and Modeling The flow sheet of PEM developed in Aspen Plus® is shown in Figure 7. Here the mixer is employed to mix the recycled streams of water from the cathode and anode sections with the freshwater feed. The input stream of the model is mixed water, which is assumed to be already deionized, at a temperature of 25 °C and a pressure of 1 bar. The fresh water (stream 1) was mixed with recycled streams of water (streams 18 & 19). The mixed water (stream 2) was pumped to provide sufficient pressure (i.e., 2.5 MPa) for the electrolysis reaction in PEM. The pumped feed water (stream 3) is heated to 80oC in a heater (H1). The heated water (stream 4) enters the electrolyzer stack modelled as stoichiometric reactor, RStoic (R1) where the electrolysis reaction of water occurs. The exit stream (stream 5) of R1 is the gaseous hydrogen, oxygen and some amount of unreacted water. Stream 5 enters a separator (S1) to separate the streams of hydrogen and oxygen product. The separator (S1) removes hydrogen (stream 6) as the top stream while the bottom stream (stream 21) is mostly oxygen and water. The bottom stream enters a divider (D2) and it is divided into two streams. The upper stream (stream 7) is only 1% of the total stream and it has mainly oxygen in it. Stream 7 is sent to the hydrogen chamber. The oxygen (stream 7) reacts with hydrogen and produces water so it can be recycled. In the same way, 1% by weight of stream 6 from the hydrogen section (i.e., stream 8) is sent to the oxygen section to react with oxygen and produce water to recycle that for electrolysis. The stream from the mixer (M3) enters a separator (S2) to separate the water from oxygen. The recovered water is recycled for electrolysis in mixer (M1). In S3, water is removed from hydrogen, and is sent to the mixer (M1) to mix with the incoming feed of fresh water. The stream from the bottom of separator (S3) is hydrogen and oxygen. This stream again enters the separator (S4) to separate hydrogen and oxygen. The oxygen gas is removed from the bottom of separator (S4) while hydrogen gas is removed from the top. Cost Estimation The Aspen Process Economic Analyzer (APEA) was used for cost estimation of each equipment. Information from the stream tables was used in equipment sizing calculations to derive parameters necessary for estimating equipment costs. By activating the economic module, the Aspen HYSYS simulation results were automatically transferred to APEA. A key step in cost estimation and economic A Comparative Techno-economic Analysis of Hydrogen Production Moses et al. © STM Journals 2024. All Rights Reserved 44 Table 8. Cost Comparison between the Three Hydrogen Production Plants. Hydrogen production process SMR SMR+CC PEM Total Plant Cost (TPC) ($) 280,344.24 327,3278.58 405,413.64 Total Plant Cost ($/year) 56,068.85 654,655.72 81,082.73 O&M fixed costs ($ (% of total O&M fixed costs)) Labour costs 149,439.60 (92.2%) 149,439.60 (50.4%) 149,439.60 (89.1%) Maintenance cost 7,008.61 (4.3%) 81,831.96 (27.5%) 10,135.34 (6.1%) Insurance cost 5,606.88 (3.5%) 65,465.57 (22.1%) 8,108.27 (4.8%) Total O&M fixed costs ($/year) 162,055.09 296,737.14 168,673.22 O&M variable costs ($ (% of total O&M variable costs)) Natural gas 234,850.91 (98.9%) 234,850.91 (97.1%) - MDEA Make up - 4,620.00 (1.9%) - Solar PV - - 1,132,397 (99.8%) [24] Cooling/Process Water 2,490.66 (1.1%) 2,490.66 (1.0%) 2490.66 (0.2%) Total O&M variable costs ($/year) 237,341.57 241,961.57 1,134,887.66 Hydrogen production cost (including all the above costs) LCOH SMR SMR+CC PEM $/𝑁𝑚3𝐻2 0.129 0.202 0.417 $/𝑘𝑔𝐻2 1.44 2.26 4.67 Table 9. Comparison of LCOH Results Obtained and Values reported in literature. Hydrogen Production Method LCOH Results Obtained LCOH Values from Literature SMR $1.44/𝑘𝑔𝐻2 $2.08/𝑘𝑔𝐻2 [1] SMR+CC $2.26/𝑘𝑔𝐻2 $2.27/𝑘𝑔𝐻2 [1] PEM $4.67/𝑘𝑔𝐻2 5.89–6.03/𝑘𝑔𝐻2 [1] Therefore, the future of hydrogen production through the PEM process is quite promising as hydrogen produced can both be used locally and exported to other parts of the world due to its the ever increasing demand. This will boost Nigeria’s economy significant and position her among the renewable energy giant in Africa. This will also aid shifting focus from fossil fuels which the country had largely depended on to sustainable and environmentally friendly energy sources. CONCLUSIONS Based on the results of this analytical work, the following conclusions were made from the findings: 1. 104.2 kg/hr of natural gas was required to produce 36 kg/hr of hydrogen gas for SMR and SMR+CC processes based on material balance. 2. 230 kg/hr of freshwater was required to produce 36 kg/hr of hydrogen gas for PEM process based on the material balance. 3. The hydrogen yield in the simulated SMR, SMR+CC and PEM processes were 74%, 93% and 99% respectively. 4. It was discovered that SMR and SMR+CC processes had specific carbon emissions of 4.9 kg CO2/ kg H2 and 0.6 kg CO2/ kg H2 respectively. It was assumed PEM process had negligible carbon emissions. 5. The Levelized Cost of Hydrogen (LCOH) was determined for SMR, SMR+CC and PEM hydrogen production processes to be $1.44/𝑘𝑔𝐻2,$2.26/𝑘𝑔𝐻2,$4.67/𝑘𝑔𝐻2 respectively. 6. The energy input of 15,137MWh per year with an electrolyzer capacity of 1.92MW/day was required to produce 11,195MWh H2 HHV per year. Journal of Alternate Energy Sources & Technologies Volume 15, Issue 1 ISSN: 2230-7982 (Online), ISSN: 2321-5186 (Print) © STM Journals 2024. All Rights Reserved 45 7. Nigeria’s abundant resources of natural gas reserves in the Niger Delta region makes it a viable site for SMR hydrogen plant. 8. The surplus sunshine and corresponding high solar radiation especially in the northeastern part of Nigeria offers a great prospect for generating renewable energy for PEM using the solar photovoltaic (PV) cells. Acknowledgements This work was supported by Nigeria’s Petroleum Technology Development Fund (PTDF) and Centre for Gas Refining and Petrochemical Engineering (CGRP), Port Harcourt, Nigeria. Abbreviations AEL Alkaline Electrolysis APEA Aspen Process Economic Analyser CCF Capital Charge Factor CCS Carbon Capture and Storage CRF Capital Recovery Factor EPC Engineering, Procurement and Construction cost GHG Greenhouse Gas GTL Gas to Liquids GPL Gas Pipelines HHV Higher Heating Value HT WGS High Temperature Water Gas Shift KPI Key Performance Indicator LCOH Levelized Cost of Hydrogen LHV Low Heating Value LNG Liquefied Natural Gas LPG Liquefied Petroleum Gas MDEA Methyl Di-ethanol Amine MEA Membrane Electrode Assembly MP Medium Pressure NG Natural Gas NLNG Nigeria Liquefied Natural Gas O&M Operations and Maintenance PEM Proton Exchange Membrane PSA Pressure Swing Adsorption PV Photo-Voltaic Cells S/C Steam to Carbon Ratio SMR Steam Methane Reforming SMR+CC Steam Methane Reforming with Carbon Capture SMR Steam Methane Reforming without Carbon Capture SOEC Solid Oxide Electrolyte TPC Total Plant Cost USD United State Dollars WGS Water Gas Shift REFERENCES 1. Nnabuife, S. 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