Con ibu ion o heS udyo He e ogeneousCa aly icReac ions
inSCFs:Hyd ogena iono Sun lowe OilinPdCa alys sa
Single‐PhaseCondi ions.
by
ElianaRamí ezRangel
Decembe 2005
Submi ed o heDepa men o ChemicalEnginee inginpa ial ul illmen o
The equi emen s o hedeg eeo Doc o a heUni e si a
Poli ècnicadeCa alunya
Supe isedby:
D .F ancescRecasens
D .M.A.La ayoz
Depa men o ChemicalEnginee ing
Uni e si a Poli ècnicadeCa alunya
TomyMomandmyG andmo he
ToOsca Mau icio
i
Summa y
Hyd ogena ionisamajo indus ialchemicalp ocess.Awide a ie yo chemicalsis
ob ainedbyca aly ichyd ogena ion.
One ypicalhe e ogeneousca aly ichyd ogena ionp ocessis hep oduc iono
ma ga ineandsho enings om ege ableoils.Thehyd ogena iono doublebondsin
a sandoilshas hepu poseo p o idingp oduc swi h hedesi edmel ingp o ileand
ex u e,acco ding o hei inaluse.Thehyd ogena edoilismo es ableandless
sensi i e ooxida ion.
Theclassicp ocessisca iedou inba ch eac o swhe e heoil,hyd ogen,andca alys
nickelpowde a emixedin ensi elya empe a u esbe ween373Kand423K.In his
case, hecompound obehyd ogena edando he eac ionp oduc sa eliquida
p ocesscondi ions; he eac ion a eislimi edby heconcen a iono hyd ogenon he
ca alys su ace.Thelow eac ion a eiscausedby helowsolubili yo hyd ogenand
hehighmass‐ ans e esis ancein heliquidphase,whichleads oadeple iono
hyd ogena heca alys su ace.In hep esenceo doublebonds, hislacko hyd ogen
alsogi es ise odouble‐bondmig a ionandcis‐ ans‐isome iza ion.
Despi eo he ac ha isome iza iono cis‐ anscon igu a ioninc eases hemel ing
poin ,con lic ingconclusionsha e esul ed oms udieson ans a yacids.Inse e al
s udies, heseisome s o meddu inghyd ogena iono a yedibleoilsha eshown o
ha esimila e ec sassa u a ed a sinc easingse umcholes e olle elsin heblood,
belie ed obeamajo causeo hea desease.Fo his eason,app ehensionandpublic
awa enessha e isen ega ding hepo en ialheal hhaza dso ans a yacidsin ake
in hehumandie .
Theaimo his esea chis os udycon inuoussingle‐phasehyd ogena iono
sun lowe oilonsuppo edpalladiumca alys susingsupe c i ical luidsasa eac ion
sol en .Thiswouldbeanal e na i ep ocess o p oducingawide a ie yo end
p oduc sha ingdi e en cha ac e is ics(iodine alue, ans‐ a yacidcon en and
sa u a edcon en mainly)o indus ial oods u sin e es obeusedaslowcholes e ol
p ecu so s o ma ga ineandsho eningbasesin henex ewyea s.Inaddi ion, he
objec i eo hes udyis oshow,onalab‐scale, hepo en ialo he e ogeneousca aly ic
eac ionsunde supe c i icalsingle‐phasecondi ions.
Summa y
ii
This hesisisbasedon hema e ialpublishedinse e al echnicalpape sandone
pa en ,whichcanbe ounda heendo he hesis.The esisiss uc u edas ollows:
Chap e 1consis so abackg ound, oexplain heideao usesupe c i ical luidsin he
hyd ogena iono a sandoils, odesc ibe hes a eo hea andwha a e heaimso
his esea ch.
Chap e 2p esen sa heo e icals udy o modelling he apo ‐liquidhighp essu e
equilib ium o sun lowe oil/hyd ogen/C3H8sys emaswellas o sun lowe
oil/hyd ogen/DMEino de ode e minesui ableope a ingcondi ions(concen a ions,
empe a u esandp essu es)whichcanb ingallhyd ogena ion eac an sandp oduc s
in oahomogeneous eac i e luidphase.
Chap e 3es ablishesabe e unde s andingo howope a ing a iablesa ec he a e
o eac ion,con e sionand inalp oduc dis ibu ioninacon inuous ecycle eac o as
wellas heexpe imen alcondi ionswhe eapo en ialCSTRp ocesscouldbeope a ed
oob ainend‐p oduc swi hindus ial oods u o in e es .Asanex ensiono hese
esul s, hekine icso he eac ioniswo kedou .
Chap e 4i isaconsequenceo he esul so hep e iouschap e andde elops he
s udyo hein apa icledi usion‐ eac ionmechanismsinsupe c i icalsun lowe oil
hyd ogena iononPd/Cca alys .
The inalchap e con ains heexpe imen alde ailso his hesis.
Thelas pa ga he s hemainconclusions,discusses hep ospec s o u he
in es iga ionsandp esen s hebibliop aphyand heappendixes.
iii
Acknowledgemen s
Iwan o hankP o esso F ancescRecasensandP o esso M.AngelsLa ayoz o he
supe isiono hisThesis.I eallyapp ecia eyou ad icesandsuppo h oughou my
esea chwo k.
I hankp o esso sJoséLuisCo inaandJo diBou o sha ingwi hmedi e en s ages
du ing heseyea so in ensi ewo k.Ialso hankpeopleo mechanicslabo a o y o
you a en ionandyou help.
Iwouldlike oexp essmyapp ecia ion o mylab‐ma es(Nancy,Fakhe ,Kamal,
Al edoandAline)and o hes uden s ha ha e ealised inalp ojec so madean
in e ship(Susana,Joan,Rubén,Sil ia,Jo di,Mónica,C is ina,AnaSo ía,Sa a,Ti ,
Thie y,Ma hewandMa ine)whomadeall oge he anenjoyablespace o wo k.
Toall headminis a i es a mysince e hanks.
I hankGene ali a deCa alunyaaswellasTheSpanishMinis yo Scienceand
Technology o he inancialsuppo du ingmydoc o als udies.
Iwish oexp essmyg a i ude opeopleo TheCleanTechnologyResea chG oupin
TheUni e si yo No inghamespecially op o esso sMa ynPoliako andPaul
Hamley.I hankEdua do,Maia,Joan,Lu,Pe e,Jason,Sil ia,Su,Rod igo,Gonzaloand
Tomásno only o sha ingwi hmeyou scien i icknowlegdebu also o ha ing un.
Ialso hankallmy iends(Lili,I án,Lau a,Dionisio,Humbe o,Leona do,people
omSan aTe esi aChu ch,Sil ia,Ti andAline) o hep aye sand o hesuppo
ha Iha e ecei ed om hem.
Mye e nalg a i udegoes omy amily o i scon inuedlo eandsuppo .Ialsowould
like omen ion helo e ha e e ydayI ecei e omOsca andmypuppiesPacaand
Coco ha hassuppo edmeall he ime.
Con en s
Con en s
Lis o Figu esix
Lis o Tablesx
Lis o Schemesxix
Chap e One
In oduc ion.1
1.1 PhysicalandChemicalP ocessinHe e ogeneousCa alys Reac ions.1
1.2 Hyd ogena ion.2
1.2.1 Hyd ogena iono Fa sandOils.3
1.2.2 Fa sandOilHyd ogena ionMechanism.7
1.2.3 Fa sandOilCon en ionalHyd ogena ionP ocess.8
1.3 Supe c i icalFluids.11
1.3.1 De ini ionandP ope ies.11
1.3.2 SCFsinHe e ogeneousCa alysis.12
1.3.3 SCFsinFa sandOilHyd ogena ion.21
1.4 Objec i esandScopeo hisThesis.27
1.5 ThesisS uc u e.28
1.6 Nomencla u e.29
Chap e Two
High‐P essu eEquilib ia.31
2.1 In oduc ion.31
2.2 Objec i esandS a egy.40
2.3 Theo e icalDe e mina iono L‐VHighP essu eEquilib ia.41
2.4 Resul sandDiscussion.45
2.5 Conclusions.55
2.6 Nomencla u e.56
Lis o Figu es
xii
Figu e4‐3:In apa icleconcen a ionp o ilesinoilhyd ogena ioninSCp opanea
457.15K, eedcomposi ion(Oil:H2::P opane):1:4:95mol%anddp=2mm.b)P=27.5
MPa.121
Figu e4‐4:In apa icleconcen a ionp o ilesinoilhyd ogena ioninSCp opanea
484.15K,P=27.51MPa.Feedcomposi ion(Oil:H2::P opane):1:4:95mol%,dp=2mm.121
Figu e4‐5Sensi i i yo hep oposedmodelwi hH2e ec i edi usi i y aluesa
484.15K,20MPa.Feedcomposi ion(Oil:H2::P opane)o 1:4:95mol%.122
Figu e4‐6:E ec i eness ac o wi h espec ohyd ogen o se e alslabca alys
pa icles hickness.123
Figu e4‐7:Es ima edmolecula di usi i yo hyd ogenand iglyce idesinSCC3H8.
129
Figu e4‐8Rela i esizeso eac an s akingplacein hepo eso 2%Pd/Cca alys
du ing hehyd ogena ion.130
Figu e4‐9:In luenceo empe a u eandp essu eon(De/D) a io.130
Figu e4‐10:Va ia iono (ρpKADs)/Dwi h empe a u e.132
Figu e4‐11:Gene alco ela iono su acedi usi i ies omSladeke al.(1974).133
Figu e5‐1:Changeinp oduc dis ibu ionandiodine alue(IV)du ingsho e m
ope a ion(P=20MPaT=444.15K, eedmolcomposi ion.:sun lowe oil=1%,H2=8%,
C3H8=91%).141
Figu e5‐2:Explosion‐p oo compa men o gases.141
Figu e5‐3:Simpli iedp ocessdiag am.143
Figu e5‐4:Schema ico hesupe c i ical luidcon inuous lowappa a us. 144
Figu e5‐5:Robinson‐Mahoney“mic o”s a iona yca alys baske eac o (Robinson,
1986).147
Figu e5‐6:Ope a inglimi s o s eelsinhyd ogense ice.Eachs eelissui able o use
unde hyd ogen‐pa ial‐p essu e‐ empe a u econdi ionsbelowand o hele o i s
espec i ecu e(Pe y,1984).149
Lis o Figu es
xiii
Figu e5‐7:Sepa a iono a yacidme hyles e ss anda dso knownconcen a ions.154
Figu e5‐8:Calib a ioncu es o maincomponen so sun lowe oilusingHPLC(210
nm).a)Me hyllinolea eandb)Me hylolea e.155
Figu e5‐8:Calib a ioncu es o maincomponen so sun lowe oilusingHPLC(210
nm).c)Me hylelaida eandd)Me hyls ea a e.156
Figu e5‐9:Sepa a iono a yacidme yles e so sun lowe oilbe o ehyd ogena ing.
158
Figu eB‐1:Expe imen alse up o hyd ogena ion eac ions.193
Figu eB‐2:GCcalib a iono a)Cyclohexanoneandb)Cyclohexanol.196
Figu eB‐3:GCcalib a iono a)Ace ophenoneandb)Phenyle hanol.198
Figu eB‐4:E ec o molo ganic‐H2 a ioonyield(523.15K,16MPaand19s.).199
Figu eB‐5a:GCcalib a iono S y ene.200
Figu eB‐5b:GCcalib a iono E hylbenzene.201
Figu eB‐6:GCcalib a iono a)Belzadehydeandb)BenzylAlcohol.202
Figu eB‐7:E ec o pHo HCO2NH4solu ionon eac ionyield.204
Figu eE‐1:Dewandbubblecu es o he e na ysys emses ima edwi h hePR‐EOS
(seeSandle ,1999):Dime hyle he (DME)/Hyd ogen(H2)/sun lowe oilsys ema
473.15Kand20MPa.Inmol%.233
x
Lis o Tables
Table1‐1:Typicalacidcomposi ionso someedibleplan a sandoils(Engelha d,
1992).5
Table1‐2:P ope ieso C‐18Fa yAcids(Engelha d,1992).6
Table1‐3:Compa isono hephysicalp ope ieso gases,liquidsandSCFs(McCoy,
1999).12
Table2‐1:C i icalp ope ieso se e alsol en s o chemical eac ions(Yaws,1999).34
Table2‐2:Solubili yo iglyce idesindi e en eac ionmedia(B unne ,1986).38
Table2‐3:Physicalp ope yda a o hyd ogena ionspecies(Yaws,1999).46
Table2‐4:Scopeo a iableso eac ion.54
Table3‐1:E ec so p ocess a iableson a eandselec i i yin ege ableoil
hyd ogena ion(Allen,1982).67
Table3‐2:Scopeo a iableso eac ion.75
Table3‐3:Coded24 ac o ialdesignma ix.76
Table3‐4:Codedcen eands a poin sdesignma ix.76
Table3‐5:E ec so heinc easeei he in he empe a u e, heLHSVo he%H2 o he
mean alueso heo he a iableson he esponses.78
Table3‐6:Pa iallyhyd ogena ed ege ableoils s.comme cialma ga ine eeds ocks
(DP.305.15‐312.15K).Da aonIodineValue, anscon en ands ea icp oduc ion.84
Table3‐7:Fi edpa ame e s alues o hekine icmodel.87
Table3‐8:Kine icpa ame e s,acco ding oequa ion(3.40), o hehyd ogena iono
sun lowe oilo e Pd/Casca alys andp opaneassol en .89
Table3‐9:Ope a ingexpe imen alcondi ionsusedin hesun lowe oilhyd ogena ion
o e Pd/Al203wi hDMEas eac ionsol en .92
Lis o Tables
x i
Table3‐10:E ec o eac ioncondi ionsonsun lowe oilhyd ogena ion.Oil
concen a ion:1mol%;P=20MPa;ca alys :0.5%Pd/Al203;sol en :DME.92
Table3‐11:Fi edkine icpa ame e s alues o Pd/Al2O3–DME eac ionsys em.96
Table3‐12:Kine icpa ame e s,acco ding oequa ion(3.40), o hyd ogena iono
sun lowe oilusingPd/Al2O3asca alys andDMEassol en .97
Table3‐13:Ac i a ionene gies epo edin hea ailableli e a u e.98
Table4‐1:To uosi y ac o s o di usioninca alys sa 6.5MPa(Bu ,1999).108
Table4‐2:To uosi y ac o s o high‐p essu eex ac iono po oussolids(S übe e al.,
1997).110
Table4‐3:E ec o pa iclediame e on hecon e siona cons an appa en esidence
ime(4.2s).Expe imen alcondi ions:0.25go 2%Pd/Ca 20MPa, eedcomposi ion
(Oil:H2::P opane):1:4:95mol%.113
Table4‐4:Expe imen al eac ion unson2%Pd/C o de e mina iono in apa icle
di usiona cons an inalIV(80‐100).Feedcomposi ion(Oil:H2::P opane):1:4:95mol
%.114
Table4‐5Modelsensi i i ywi h i edpa ame e sa 484.15K,20MPaand eed
composi ion(Oil:H2::P opane)o 1:4:95mol%.123
Table4‐6:In insickine icpa ame e s o heSCsun lowe oilhyd ogena iononPd/C.
124
Table4‐7:Cons ainso Le enbe g‐Ma qua d algo i hm.125
Table4‐8:Fi ede ec i edi usioncoe icien s o hyd ogena ionspecieson2%Pd/C
ca alys (dp ange=0.47‐2mm).125
Table4‐9:Es ima edselec i i ies o SCsun lowe oilhyd ogena ionon2%Pd/Ca
487.15K,200MPaanda eedcomposi ion(Oil:H2::P opane)o 1:4:95mol%.127
Table4‐10:Molecula di usi i ies o C3H8‐T iglyce idesandC3H8‐H2unde se e al
ope a ingcondi ions.128
Table4‐11:De/D a io o iglyce idesandhyd ogeninSCp opaneon2%Pd/C.129
Lis o Tables
x ii
Table4‐12:(ρpKADs)/D a io o iglyce idesinSCp opaneon2%Pd/C.132
Table5‐1:Equipmen lis o hesupe c i icalexpe imen alappa a us.145
Table5‐2:F‐126s eelcha ac e iza ion.150
Table5‐3:Ch oma og aphicanalysiso sun lowe oil awma e ial.157
TableA‐1:Gene alo e iewo ca aly iche e ogeneous eac ioninSCFs.187
TableB‐1:Sc eeninghyd ogena ion eac ions.192
TableB‐2:E ec o ope a ing a iablesoncyclohexanolyield.196
TableB‐3:E ec o ope a ing a iableson1‐phenyle hanolyield.199
TableB‐4:E ec o ope a ing a iablesone hylbenzeneyield.201
TableB‐5:E ec o ope a ing a iablesonbenzylalcoholyield.203
TableB‐6:Resea ch esul sincompa isonwi h hoseo B ysone al.(2004).204
TableC‐1:Sun lowe oil iacylglyce olcomposi ionby e e sed‐phasehigh
pe o manceliquidch oma og aphywi h lameioniza ionde ec ion(Ne e al.(1994).
207
TableC‐2:Amb oseg oupcon ibu ions o c i icalcons an s(Reide al.,1987).209
TableC‐3:Es ima edc i icalp ope ies o pu ecomponen so sun lowe oil.210
TableC‐4:Coe icien s o equa ionC.10(Reide al.,1987).211
TableC‐5:Coe icien s o equa ionC.14.212
TableC‐6:Es ima edsun lowe oilc i icalcons an s.214
TableE‐1:Dewandbubblecu esda a o he e na ysys emDime hyle he
(1)/Hyd ogen(2)/Sun lowe Oil(3)sys ema 453.15Kand20MPa,xdeno esei he
liquido apo phasemole ac ion.232
TableF‐1:E alua iono in apa iclemass anspo limi a ion.236
TableG‐1:Molecula di usi i ies o C3H8‐T iglyce idesandC3H8‐H2unde se e al
ope a ingcondi ions.241
xix
Lis o Schemes
Scheme1‐1:Chemis yo iglyce ides(Engelha d,1992).4
Scheme1‐2:Unsa u a edca bon‐ca bondoublebondhyd ogena ion.7
Scheme3‐1:Kine icmodel o oilhyd ogena ionde elopedbyBailey(1949).59
Scheme3‐2:Kine icmodel o co onseedoilhyd ogena ionbyElbidandAlb igh
(1957).60
Scheme3‐3:Kine ic eac ionsequence o oilhyd ogena ionbyAlb igh (1965).61
Scheme3‐4:Kine icmodel o co onseedoilhyd ogena ionbyAlb igh (1967).62
Scheme4‐1:Flowcha o hepa ame e i ingp ocedu e o hesmalles pa icle
diame e ca alys (dp=0.47mm,2%Pd/C).117
Scheme4‐2:Flowcha o hepa ame e i ingp ocedu e o hela ges pa icle
diame e ca alys (dp=2mm,2%Pd/C).118
SchemeB‐1:Hyd ogena iono cyclohexanone.195
SchemeB‐2:Hyd ogena iono ace ophenone.197
SchemeB‐3:Hyd ogena iono s y ene.200
SchemeB‐4:Reac i i yo o ganicg oups.201
SchemeB‐5:Hyd ogena iono benzaldehyde.202
SchemeC‐1:Pseudo‐componen which ep esen sa ege ableoil(Pe edae al.,2002).
207
1
Chap e One
In oduc ion.
1.1PhysicalandChemicalP ocessinHe e ogeneousCa alys
Reac ions.
Byde ini ion,inhomogeneousca alysis, eac an sandca alys o masingle luid
phase,whe easinhe e ogeneousca alysis eac an sandca alys a ep esen indi e en
phases(SeeFigu e1‐1), ende ingmassandhea ans e h oughin e phasesa
necessa yp e equisi e o eac ion.
Figu e1‐1:Sequenceo physicalandchemicals epsoccu inginhe e ogeneousca aly ic
gas/liquid eac ion(e.g.hyd ogena iono liquidcompound).Pa ashowsa ep esen a i e
sec iono he eac o con en consis ingo agasbubbleandasolidca alys pa icleand
co espondingmass‐ ans e bounda ylaye s( esis ances).Pa bp o idesamagni iedc oss
sec iono heca alys pa icle(Baike ,1999).
In oduc ion
8
Asimila se ieso s epsoccu swhenoneo hedoublebondo apolyunsa u a ed a y
acidchainishyd ogena ed.Isome iza ion eac ionsalsooccu in hesecases,anda
leas pa o hedoublebondsisisome ized onewposi ions.I ame hylene‐
in e up eddieneis eac edon heca alys su ace, hedoublebondsmaybe
conjuga edbe o esa u a iono oneo hebonds.Also, heconjuga eddienemaybe
deso bed o m heca alys su acein o hemainbodyo oilbe o ebeing eadso bed
andpa iallysa u a ed.
I hemix u e obehyd ogena edcon ainsbo hmonoenesanddienesandpolyenes,
he emaybecompe i ionbe ween hedi e en unsa u a edsys ems o heca alys
su ace.Thus hedienesmaybep e e en iallyadso bed om heoil o heca alys
su aceandpa iallyisome izedand/o hyd ogena ed oamonoeneand hendeso bed
odi use o hemainbody o heoil:Thedi‐andpolyenesa ep e e en iallyadso bed
un il hei concen a ionin heoilis e ylow,and hemonoenes henmaybeadso bed
and eac ed.
Since heoils ha a ehyd ogena eda ecomposedo amix u eo a yacids, he
selec i i yo he eac ionis e yimpo an .
1.2.3 Fa sandOilCon en ionalHyd ogena ionP ocess.
The o alannualp oduc iono hyd ogena edoilsisabou 25million ons(Mielke,1992
andFi ch,1994).Theupg adingo oilsbyhyd ogena ionandisome iza ionisusually
ca iedou inei he ba cho con inuousp ocesses(mos lyba ch)wi has i edslu y
phase eac o (Sou elis,1956).Theindus yisdomina edbydead‐endba ch
hyd ogena o swi ha2:1o 3:1liquidle el odiame e anda op“dead”space o
hyd ogenaccumula ion.A ypicalindus ialba chdead‐endp ocessisshowninFigu e
1‐4.Apo iono heoilcha gewhichisweighedin o hesupply ankisused omix
wi h heca alys (usuallybasedonnickel,load anging om0.01 o0.2w %pe ba ch)
in hemix ank(madeo ca bons eelandwi hacapaci yo 5 o20m3)unde acuum
and heagi a o andhea inga es a ed.Whena empe a u eabou 323.15Kbelow he
eac ion empe a u eis eached, acuum u nedo ,andhyd ogenisadded.Agi a ion
o heca alys ‐oilmix u ese es hedoublepu poseo p omo ingsolu iono hyd ogen
in heoilandcon inuously enewing heoila heca alys su ace.Coolingwa e is
u nedon,and hehea o eac ioninc eases hesys em empe a u e o hedesi ed
eac ion empe a u e.When he eac ionp essu ehadbeen eached,onlyenough
hyd ogenisadded omain ainp essu e.Finally,when he eac ionhasbeencomple ed,
hyd ogen lowisdiscon inuedand heho p oduc is henpassed h oughahea
Chap e One
9
exchange whe ei isused op ehea heincoming eed.Thep oduc iscooled oabou
373.15Kand il e ed o emo e hepowde edca alys whichis he eusedin
subsequen cycles.
Figu e1‐4:Dead‐endba chhyd ogena ionp ocess o iglyce ideoils(Alb igh ,1967).
Al hough hedead‐endhyd ogena o jus desc ibeddomina es heindus y,o he
eac o sa eo e edaslicensedp ocesses.Theseincludeloop eac o s,whichemploysa
mixingje ha useshyd ogen op opel heoilin o he eac o whilemixing heliquid
andci cula ingi h oughex e nalhea exchange s.Al hough, heloop eac o sa e
be e mixedandp o idebe e hea ans e , heya emo edi icul os a upanda e
mo elikely op oduceca alys inesi no p ope lyope a ed(Rase,2000).
Ope a ingcondi ions a ydependingon eedanddesi edp oduc .No mal angesa e
393.15‐473.15Kand0.1‐0.5MPa.The eac ion imeisabou 2hou s.The eac o
ope a esini iallyin hesemiba chmodeashyd ogenisaddeda ela i elyhigh a es
un il hep essu ebuildsup o hedesi ed alue.A e his ime,onlyasmallamoun o
hyd ogenisadded omain ain hep essu e,adeclineo whichiscausedbyhyd ogen
consump ionandableedgass eamope a ed oexpelimpu i ies.In hesecondmode
In oduc ion
10
hyd ogencon inues obubblebu a alow a e.Theimpelle nea hesu acewillalso
d awsomehyd ogen om he apou spaceandcause u he con ac ing.Theend
poin canbede ec edapp oxima elyby e ac i eindex,whichco ela eswi hiodine
alueo byno hinghyd ogenconsump ion.I heendpoin isc i ical, heagi a o can
bes opped oallow ime o mo e ho oughlabo a o ywo ksuchasiodine alueand
isome analysis.Thisp ocedu eis imeconsuming.Al e na i ely,ba cheso di e ing
endpoin scanbeblended op oduce hedesi edp oduc .Finalgoodp oduc scanalso
bep oducedbymixingahighe mel ingmo esa u a edp oduc wi haliquidoil
con aininghighamoun so acidg oupswi h woand h eepai so doublebondssuch
assa lowe ,soybeanandco noils.(Rase,1977).
Asa ule,liquid‐phasehyd ogena ionsa es onglyexo he mic eac ions(hea so
eac ionsbe ween65‐550KJ/mol).Fo his eason, eac o sha e obe i edwi hla ge
hea ‐exchangea eas,ei he in e nallyo onanex e nalci cula ionloop.Theex e nal
exchange o e s head an ageo ha ingalmos unlimi edspacea ailable o i s
layou .Howe e , empe a u edis ibu ionin he eac o isno uni o mbecause he
hea isgene a edand emo edin wodi e en loca ions.Adynamic empe a u e
egula ionsys emisneededbecause hesys em equi es apidswi ching omhea ing
( os a he eac ion) o ullcooling.Runawaycondi ionsa epossiblebecause he
eac ionisexo he micandi isope a edin heba chmode.Fo una ely, he eac ion
canbes oppedalmos ins an aneouslybysupp essing hemass ans e o hyd ogen
(bys opping heagi a o , o example).Ne e heless hesa e ysys emhas obe
designedca e ully o ailsa eope a ionand hequickes possible esponse(Lande
andScubla,1995).
Thelowsolubili yo H2in heoiland hehighmass ans e esis ance o he
hyd ogen om hegasphase o heca alys su ace(SeeFigu e1‐1)leads oadeple ion
onH2a heca alys su ace,whichin u n,slowsdown he eac ion a eandgi es ise
odoublebondmig a ionandcis‐ ansisome iza ion(Rylande ,1985andG aue al.,
1988).On heo he hand,in e nal anspo limi a ionsonhyd ogenand iglyce ides
o heac i esi eso heca alys ha eas ongin luenceonbo hselec i i yand ans
p oduc ion.Fo pa iallyhyd ogena edoil,a anscon en o 30 o50%isno mal oa
iodine alue(IV)o 70.
Thecu en comme cialba chp ocessusingnickelca alys ,ei he suppo edon
kieselguh o silica,hassomedisad an ages:(1)Discon inuousope a ion,(2)Low
space‐ ime‐yields,(3)Undesi ableby‐p oduc sasa esul o s onghyd ogenmass‐
ans e and(4)High a iablecos s(e.g.man‐powe ,ene gyand il a ion).On he
Chap e One
11
o he hand, heuseo hesuppo ednickelca alys alsoleads oaddi ionalp oblems
includingundesi ableby‐p oduc s( ans a yacids)wi hanimpac onheal h(high
choles e olandlipidle elinblood),ca alys deac i a ion h ough o ma iononnickel
soapsin ee a yacidhyd ogena ion,nickel esidueswhichcouldbe oxic(Niboe e
al.,1993).
Away oinc ease heconcen a iono hyd ogena heca alys su aceis oin oducea
supe c i icalsol en in o he eac ionmix u e.The oleo supe c i ical luidis
minimized he anspo esis ance o hyd ogen.Asaconsequence, hee ec i e
hyd ogenconcen a iona heca alys su aceissigni ican lyenhanced,leading o
ex emelyhigh eac ion a escompa ed o he adi ional wo‐phasegas‐liquid
app oach(Baike ,1999andFan,1999).
1.3Supe c i icalFluids.
1.3.1De ini ionandP ope ies.
Asupe c i ical luid(SCF)isde inedas hes a eo acompound,mix u eo elemen
abo ei sc i icalp essu e(pc)andc i ical empe a u e(Tc)bu below hep essu e
equi ed ocondensei in oasolid(JessopandLei ne ,1998).Howe e , helas e mo
hisde ini ion(“bu below hep essu e equi ed ocondensei in oasolid”)is
gene allyomi edbecause hep essu e equi ed ocondenseaSCFin oasolidis
gene allyimp ac icablyhigh(Cli o d,1998).Thec i icalpoin co esponds o he
highes TandPa which hesubs ancecanexis asa apou andliquidinequilib ium.
Figu e1‐5:De ini iono SCs a e o apu ecomponen .CPc i icalpoin ,TP iplepoin ,TC
c i ical empe a u e,PCc i icalp essu e(B unne ,1994).
In oduc ion
12
Thep ope ieso anSCF a yo e awide angedependingon he empe a u eand
p essu e,bu a egene allyin e media ebe ween hoseo liquidsandgases(Table1‐3).
Howe e , hesep ope ies,especiallydensi y,a ehighlysensi i e osmallchangesinT
andPnea hec i icalpoin .
Table1‐3:Compa isono hephysicalp ope ieso gases,liquidsandSCFs(McCoy,1999).
P ope yGasSCFLiquid
Densi y(g/cm3)10‐30.41
Viscosi y(Pas)10‐510‐410‐3
Di usi i y(cm2/s)0.110‐310‐5‐10‐6
Ascanbeseen omTable1‐3, hedensi yo SCFsisapp oxima ely, woo de so
magni udehighe han ha o agasbu i isalsoless hanhal o ha o aliquid.
Viscosi yanddi usi i ya ehighlydependen onTandPchanges.Bo hp ope iesa e,
ingene al,a leas ano de o magni udelowe andhighe , espec i ely,compa ed o
liquids.
Theliquid‐likedensi yo anSCF,enablesmanyma e ials obedissol ed oale el
whichiso de so magni udehighe han ha expec ed omidealgasconside a ions.
Tempe a u eandp essu ecan he e o ebeusedas a iables ocon ol hesolubili y
andsepa a iono asolu e.Incon as ,di usi i yand iscosi y ep esen anspo
p ope ies,meaning ha hedi usiono aspeciesinaSCFwilloccu as e han ha in
aliquid.Also,SCFswillbemo ee icien a pene a ingin omic opo oussolid
s uc u es(JessopandLei ne ,1998).Themos impo an ea u eo SCFs ha eally
di e en ia e hem omliquidsol en sis hei unabili y:simpleal e a ionsin
empe a u eandp essu emodi y hephysicalp ope ies omgas‐like oliquid‐like.
SCFsha ebeenconside ed e yuse ulas eac ionmediabecauseo hehighsolubili y
o liquidandsolids,especiallywhencomp essed oliquid‐likedensi ies,bu also hei
unabili y,whichallowsone ocon ol hesolubili yo o ganicsolu es.Inaddi ion,
SCFsha e heabili y odissol egasessuchasH2,O2andCO(Baike ,1999).
1.3.2 SCFsinHe e ogeneousCa alysis.
Ca aly iche e ogeneous eac ionsa egene allycon olledby he a eo di usiono he
eac an s oandin o heca alys su ace(seeFigu e1‐1).SCFha eag ea dealo
po en ial o he e ogeneousca alysis,whe e he eac an sand heca alys a ein
di e en phases.No mally, heca alys sasolid,and heSCFisusedasasol en o
Chap e One
13
o ganicsubs a es.Theuseo SCFsas eac ionmediacanbea ealad an agewhen
usinghe e ogeneousca alys s,since hedi usion a esa eenhancedcompa ed o
eac ionsin heliquidphase.Di usionisno onlyenhancedin hebulk luid,bu also
wi hin hepo eso heca alys pa icles(JessopandLei ne ,1998).
SCFs,ei he usedassol en so eac an s,p o idese e aloppo uni ies oenhanceand
con olhe e ogeneousca aly ic eac ions.Impo an possibili iesinclude(i)con olo
phasebeha iou ,elimina iono gas/liquidandliquid/liquidmass ans e esis ances,
(ii)enhanceddi usion a ein eac ionscon olledbyex e nal( luid/pa icle)di usion,
(iii)enhancedhea ans e (i )easie p oduc sepa a ion,( )imp o edca alys li e ime
bydissolu iono deac i a ingdeposi s,( i) enabili yo sol en p ope iesbyp essu e
andcosol en s,( ii)enhancemen o he eac ion a e,( iii)con olo selec i i yby
sol en ‐ eac an (solu e)in e ac ionand(ix)p ocessin ensi ica ion(Baike ,1999).
Mo eimpo an is ha due o hehighe eac ion a esandeasyp oduc sepa a ion, he
combina iono he e ogeneousca alys swi hSCFsallows heuseo con inuous low
eac o s(Baike ,1999).Compa ed oliquid‐phase eac ions, eac ionsinSCFa e
cha ac e izedby educed iscosi yandenhancedmass ans e .Inaddi ion, hegood
he mal anspo p ope ieso supe c i ical luidsa eanad an agebecause
hyd ogena ionisusuallyahighlyexo he mic eac ion.Thebene i so using ixed‐bed
con inuous eac o sincludebe e p ocesscon ol,inc easedp oduc i i y,easy
sepa a iono p oduc s om heca alys andenhancedma ginso sa e y(Ande son,
2001).Fu he mo e,con inuous eac o s o SCFsp esen manyad an ageso e ba ch
eac o s.Fo example, heydono need obedep essu ised oload he eac an so o
eco e hep oduc s.Thep oduc eco e yisaccomplishedbyadep essu isa ions ep
once he eac ionis inished(Hydee al.,2001).Indus yinpa icula , a ou s
con inuousp ocessesbecause heya emo ecos e icien and he eac o scanbekep
smalle insize(Tundo,1991).This educ ioninsize educesbo hcos sandsa e y
p oblemso hehigh‐p essu eequipmen needed o supe c i ical eac ions.
Awide angeo ca aly ic eac ionscanbeca iedou insupe c i ical luids,suchas
Fishe ‐T opschsyn hesis,isome iza ion,hyd o o mila ion, a sandoilshyd ogena ion,
syn hesiso chemicals,bioca alysisandpolyme iza ion(SeeFigu e1‐6).
In oduc ion
14
Figu e1‐6:Ca aly iche e ogeneous eac ionsca iedou inSCFs.
SCFs
in
Ca aly ic
He e ogeneous
Reac ions
Alkyla ion (p opene,isopen ane,CO
2
)
Fane al.(1997‐1998)
Sub amaniam and co‐wo ke s (1998)
Poliako and co‐wo ke s (1998)
Amina ion (NH
3
)
Fishe e al.(1998)
FTSyn hesis (p opane,n‐pen ane,n‐hexane)
Yoko o e al.(1990,1991)
Fane al.(1992,1997)
Buku e al.(1997)
Sub amaniam and co‐wo ke s (1998)
C acking (hep ane)
Da das e al.(1996)
Isome iza ion (CO
2
and cosol en s )
Sub amaniam and co‐wo ke s
(1989‐1998)
Til sche e al.(1984‐1987)
Disp opo iona ion (bu ane,benzene,n‐
pen ane)
Til sche and co‐wo ke s (1984,1987)
Niu and Ho mann (1996‐1997)
Oxida ion (CO
2
)
Dooley and Knop (1987)
Hyd ogena ion
Gene alO ganic Compounds (CO
2
,p opane,wa e )
Poliako and co‐wo ke s (1997‐1998,2004)
Mindi e al.(1995‐1996)
Be ucco and co‐wo ke s (1996‐1998)
K öche e al. (1996‐1998)
Chouchi e al. (2001)
Sub amaniam and co‐wo ke s (2001)
Fa s and Oils,FAMEs (CO
2
,p opane,)
Tacke e al. (1995‐1997,2003)
Ha öd and co‐wo ke s (1995‐1996)
Ande sson e al. (2000)
King e al. (2001)
Mache and Holmq is .(2001)
Recasens and co‐wo ke s (2004)
SCFs
in
Ca aly ic
He e ogeneous
Reac ions
Alkyla ion (p opene,isopen ane,CO
2
)
Fane al.(1997‐1998)
Sub amaniam and co‐wo ke s (1998)
Poliako and co‐wo ke s (1998)
Amina ion (NH
3
)
Fishe e al.(1998)
FTSyn hesis (p opane,n‐pen ane,n‐hexane)
Yoko o e al.(1990,1991)
Fane al.(1992,1997)
Buku e al.(1997)
Sub amaniam and co‐wo ke s (1998)
C acking (hep ane)
Da das e al.(1996)
Isome iza ion (CO
2
and cosol en s )
Sub amaniam and co‐wo ke s
(1989‐1998)
Til sche e al.(1984‐1987)
Disp opo iona ion (bu ane,benzene,n‐
pen ane)
Til sche and co‐wo ke s (1984,1987)
Niu and Ho mann (1996‐1997)
Oxida ion (CO
2
)
Dooley and Knop (1987)
Hyd ogena ion
Gene alO ganic Compounds (CO
2
,p opane,wa e )
Poliako and co‐wo ke s (1997‐1998,2004)
Mindi e al.(1995‐1996)
Be ucco and co‐wo ke s (1996‐1998)
K öche e al. (1996‐1998)
Chouchi e al. (2001)
Sub amaniam and co‐wo ke s (2001)
Fa s and Oils,FAMEs (CO
2
,p opane,)
Tacke e al. (1995‐1997,2003)
Ha öd and co‐wo ke s (1995‐1996)
Ande sson e al. (2000)
King e al. (2001)
Mache and Holmq is .(2001)
Recasens and co‐wo ke s (2004)
Chap e One
15
Themajo i yo hes udieswhichha ebeenconduc edonSCFs,ha e ocusedon ou
luids,CO2,e hane,e heneandwa e .Howe e ,CO2isby a , hemos widelyused
SCF(JessopandLei ne ,1999).ThisisbecauseSCCO2isnon‐ oxic,non‐ lammable,
ela i elycheapandine .AppendixAp o idesano e iewo heses udies,
indica ing hecondi ionsandmain ea u eso he a iousin es iga ions.
In hecaseo alkyla ion eac ion,Fane al.(1997‐1998) ound om heexpe imen al
esul s ha hesupe c i icalope a ionmode esul edinsigni ican lyslowe ca alys
deac i a ion,highe ca alys ac i i yaswellasanimp o edselec i i yo hesubs a es.
Theinc easein heca alys li e‐ imehasbeena ibu ed o hehighe solubili yo
hea yo ganic esidues(“coke”)inSCFs hanin heco esponden gases.Thecoke
o med,migh block heca alys ac i esi es; he e o e,deac i a ing heca alys .Due o
heenhanceddi usi i yinSCFs, he ans e o cokep ecu so s om hein e naland
heex e nalca alys su aceisaccele a ed,inc easing heca alys li e‐ ime(Poliako
andco‐wo ke s,1998,Sub amaniam,2001andSub amaniame al.,2002).
Fische e al.(1998)in es iga ed hein luenceo p essu eoncon e sionandp oduc
selec i i yo hein luenceo p essu eoncon e sionandp oduc selec i i yo he
amina iono amino‐1‐p opanolwi hammoniao e aCo‐Feca alys .Theexpe imen s,
whichwe econduc edinacon inuous ubula eac o a 468.15Kandamola eed
a ioo eac an sR‐OH/NH3=1:20in he o alp essu e ange5.0‐13.5MPa,indica eda
s ikingchangeo heselec i i y o hedesi edp oduc ,1,3‐diaminop opane om4%
o40%in henea c i ical egiono ammonia(Tc=405.15K,Pc=11.4MPa).Compa ing o
selec i i y,co espondingchangesincon e sionwe esmall.
Da dase al.(1996)usedaninsi ucylind ical e lec ancein a ed echnique(CIR‐IR) o
s udysupe c i icaln‐hep anec acking.Thei esul sshowed ha asigni ican numbe
o B øns edacidsi esand e minalsilanolsa econsumeddu ingca aly icc acking,
newspec albandsappea andacidsi es egainedasigni ican pe cen ageo hei
ini ialconcen a ionso hei ini ialconcen a ionsdu ingsupe c i icalc acking,
indica ing ha heca alys s a s eco e ingi sac i i yunde he ep ocesscondi ions.
Til sche andco‐wo ke s(1984,1987)s udied hedisp opo iona iono 1,4‐
diisop opylbenzeneunde gaseousandsupe c i icalcondi ionsusingazeoli e13NaHX
ca alys inanin e naldi e en ial eac o .Theau ho sconcluded ha aising he
p essu ein hesupe c i ical egionenhancesdeso p iono headso bedp oduc sdue
oinc easeddissolu ionpowe o SCFandsugges ed ha hise ec canbeused o
p olongca alys li e imeand odi ec hep oduc dis ibu iono mul iple eac ions.
In oduc ion
16
NiuandHo man(1996,1997) eached hesameconclusion o heca alys li e imein
hedisp opo iona iondee hylbenzeneo e HY‐zeoli eunde supe c i icalcondi ions.
Vie illee al.(1993‐1994)in es iga ed hees e i ica ionso oleicacidbyme hanol
ca alyzedbysul onicacid esinsinsupe c i icalCO2.Thees e i ica iono ca boxylic
acidswi halcoholsisanexamplei a e e sible eac ion,whichhasbeens udieda
supe c i icalcondi ions.Theau ho s oundsimila pa ame icsensi i i yo he eac ion
a einsupe c i icalca bondioxideasinn‐hexane.Howe e he eac ionwas as e in
supe c i icalca bondioxide.This ac wasa ibu ed oinc easedsolubiliza iono
me hyolea eandhighe di usi i y.
Conside ablee o hasbeenexpendedinexplo ing heapplica iono supe c i ical
luidsinFishe ‐T opsch(FT)syn hesis(Baike ,1999),whichp o idesameans o
syn hesizehighe hyd oca bonsin heliquid uel ange omsyn hesisgas(COand
H2).Theclassicalsyn hesis ou ein ol esanexo he micgas‐phase eac ion,and
consequen lye icien hea emo alisessen ial.Ano he p oblema ises om
condensa iono highe hyd oca bons o meddu ing eac ionwi hin heca alys po es,
whichcancauseca alys deac i a ion.Inaliquid‐phasep ocess, helowe di usi i y
leads omass‐ ans e limi a ionsandconsequen ly olowe o e all eac ion a e.In
someea lys udies,Yoko aandco‐wo ke s(1990,1991)demons a e ha he
supe c i icalFT eac ionshowsuniquecha ac e is icssuchashighdi usi i yo
eac an gases,e ec i e emo alo eac ionhea aswellasinsi uex ac iono high
molecula weigh hyd oca bons(wax).Theseau ho sconcluded ha in hesupe c i ical
phase eac ion,bo h hedeso p ionand hedi usiono hep oduc we esowell‐
balanced ha heo e allmass ans e o hep oduc swasmos e ec i ein he
supe c i icalphaseand hus hehyd ogena iono p ima yole inswase ec i ely
supp essed.
Buku e al.(1997)s udied hee ec o p ocesscondi ionsonole inselec i i ydu ingFT
syn hesisinsupe c i icalp opane.They ound ha he o alole inand2‐ole in
selec i i ywe eessen iallyindependen o eac ion empe a u ebu unde supe c i ical
condi ions he o alole incon en wasg ea e while he2‐ole incon en dec eased.The
au ho sconcluded ha undesi edseconda y eac ions(isome iza ion,hyd ogena ion
and eadso p ion)o highmolecula weigh α‐ole insoccu oasmalle ex en du ing
supe c i icalope a ion,due ohighe di usi i iesanddeso p ion a eso α‐ole insin
hesupe c i icalp opane hanin heliquid‐ illedca alys spo es.
Chap e One
17
On he i s eac ionin es iga edunde supe c i icalcondi ionswas hecis/ ans
isome iza iono α‐ole ins(Til sche andco‐wo ke s,1984‐1987).Pa icula ly, he
isome iza iono 1‐hexene u nedou obeasui ablemodelsys em o in es iga ion.
In e es ing ea u eso his eac iona e hep oduc o ma ion iaasys emo complex
pa allelandconsecu i e eac ionsand he ac ha ansisome sa e
he modynamicallymo es able hancisisome s.Theseau ho s ound ha heini ial
cis/ ans a ioinc easeswi hp essu ein hesupe c i ical egion.Thisbeha iou is
a ibu ed o hekine ic a ou ingo cis‐hexane‐2 o ma iondue oi senhanced
deso p ionin hesupe c i icalphase.
Sub amaniamandco‐wo ke s(1989‐1998)ha e ocused hei a en ionon he
isome iza iono 1‐hexeneca alyzedbyP /alumina.Con inuous ixed‐bed eac o
expe imen swe eused oin es iga eca alys deac i a ioninhexane/CO2mix u es.The
ac i i yo heca alys dec easeda asubc i icalp essu e,whe easa anea lyiden ical
empe a u ebu supe c i icalp essu enoca alys deac i a ionwasobse ed.The
s ableac i i yo heca alys unde supe c i icalcondi ionswasexplainedby he
sol en powe o heSCFwhichp esumablyp e en eddeposi iono highe molecula
weigh oligome sin heca alys po es.Insubsequen wo ks(Sub amaniamandco‐
wo ke s,1990,1992and1994) heseau ho sconcluded ha nea ‐c i ical eac ion
mix u esp o ideanop imumcombina iono sol en and anspo p ope ies ha is
be e hanei he subc i ical(gas‐like)o densesupe c i ical(liquid‐like)mix u es o
maximizing heisome iza ion a esandminimizingca alys deac i a ion a es.
DooleyandKnop (1987)s udied hepa ialoxida iono oluene obenzaldehydewi h
ai insupe c i icalCO2in hep esenceo edoxo acidca alys s.Thehigh‐p essu e
p ocessa o dsmuchbe e selec i i y opa ialoxida ionp oduc s.Asimila
imp o emen wasno icedbyGa neyandSo anko(1993and1993) o heoxida iono
p opene op opyleneglycolunde supe c i icalcondi ionsandbyFane al.(1997) o
heoxida iono isobu ane o e ‐2‐bu ylalcohol.
Mos o hewo kinsupe c i icalwa e has ocusedonsupe c i icalwa e oxida ion,
whichisane ec i emeans o comple eoxida iono manyo ganicwas es.Ad an ages
oconduc ing his eac ionabo e hec i icalpoin include as e eac ion a es,single
luidphase,andcomple emiscibili yo nonpola o ganicswi hsupe c i icalwa e
(Baike e al.,1999).
Hyd ogena iono o ganiccompoundsisap ocesso majo chemicalimpo ance
(Poliako e al.,1999).GaseousH2isanexpensi eand e sa ile eagen o
In oduc ion
24
p oducedha ingdi e en iodine alues,pe cen age am a yacidcon en ,and
d oppingpoin so solid a indices.Al houghaddi iono ca bondioxide o he luid
phasecon aininghyd ogen e a ds heo e all eac ion a einmos o hes udiedcases,
hemajo i yo p oduc sha elow ans a yacidcon en ,consis en wi hanonselec i e
modeo hyd ogena ion.
Mache andHolmq is (2001)ca iedou hehyd ogena iono palmoilinnea ‐c i ical
andsupe c i icalp opaneusingasmall(0.5cm3)con inuous ixed eac o and1%Pd/C
asca alys , empe a u e(338.15–408.15K),H2/ iglyce idemol a io(4–50),and
esidence ime(0.2–2s) oassess heiodine alue(IV)asa unc iono heope a ing
a iables.Theau ho sobse edhigh eac ion a es(a esidence imeo 2sissu icien
a 393.15K),whichindica es ha he eac ioncouldalsobe unsuccess ullya lowe
empe a u es.
Ramí ezandLa ayoz(2002)p esen edp elimina yexpe imen alda a oma
con inuous,single‐phasehyd ogena iono sun lowe oilonPd/Cca iedou ina
Robinson‐ Mahoney– ypeo eac o ,wi ha ixedbedca alys usingp opaneasSC
sol en .Awide angeo hyd ogena ionp oduc swe eob ainedwi hce ainplas ic
cha ac e is ics o u he oodapplica ionby uning heope a ingcondi ions.
Inala e wo k,Ramí eze al.(2004) epo ed he luid‐phasehyd ogena ionon
sun lowe oilindensep opanewi h1mol% ege ableoil,9%H2,and90%p opanea
428.15‐488.15Kand20MPa.The eac ionwas uncon inuouslyinasingle‐ luidphase,
usingalabo a o yse up.Theca alys was2%Pdsuppo edonC.Theau ho sused he
designo expe imen sand esponsesu aceme hodology oachie eop imum
hyd ogena ioncondi ions o Pdca alys inSCp opaneinacon inuouss i ed eac o
aswell oshow ha i waspossible oob ainahyd ogena ed a wi h2‐3w % ans
con en inasinglepass h ough he eac o inacon inuousp ocess,wi ha inaliodine
aluea ound70.Theexpe imen al esul sshowed ha onep incipalad an ageo
usingp opaneasasupe c i ical luidis helow ansacidcon en ,aswellaslows ea ic
acid,compa edwi h ha o hecon en ionalp ocess.Nodeac i a iono heca alys
wasobse ed.Fu he mo e,kine icso he eac ionusing heHashimo oe al.(1971)
schemewasde e mined.
F om he ac smen ionedp e iously, hecombina iono suppo edp eciousme al
ixed‐bedca alys s oge he wi hnea c i icalo supe c i icalsol en c ea esnew
possibili ies o con inuous ixed‐bedhyd ogena ionswi hsigni ican lyimp o ed
space‐ ime‐yieldsandca alys li e‐ imes.Sho esidence imesandwell‐balanced
Chap e One
25
di usionanddeso p iono p oduc sand eac an s esul sinadec easeinundesi able
by‐p oduc sand he e o ehighe selec i i y.Themainad an ageso supe c i ical
single‐phase a andoilhyd ogena iononsuppo edme alca alys scanbesumma ized
as ollows(Hä ode al.,2001):
• Ex emelyhigh eac ion a esha ebeenachie ede en o e yla gemolecules.
The eac ion imeisin he angeo secondscompa ed ohou sin he adi ional
p ocess; he e o eonlycon inuous eac o sa esui able o his ypeo eac ions.
• Con olled eac ionselec i i y.Theconcen a iona heca alys su ace(bo h
subs a eandhyd ogen)canbecon olledindependen lyo hep ocess
condi ions.Theunique ea u eis ha e yhighconcen a ionso hyd ogencan
beachie edleading omuch o example o hesupp essiono dec easeo ans‐
a yacidsinpa ialhyd ogena ion.
• Thep oduc quali ycanbeimp o ed.Dependingon hechosen eac ion
condi ions,awide a ie yo endp oduc scanbep oducedha ingdi e en
iodine alues,d oppingpoin so solid a indiceswi hlowpe cen age ans a y
acidcon en s.
• Ex emelyhighdeg eeso con e sioncanbeachie edbyinc eased he eac ion
imeg ea ly.Howe e , he eac o olumewills illbe e ysmallbecauseo he
ex emelyhigh eac ion a e.
• Thesho esidence imesin he eac o gi elesssubjec o ime‐ he mal
deg ada iono hea ‐sensi i ep oduc sand/o subs a es.
• Theaddi iono hesol en makespossible ocon ol he empe a u ein he
eac o despi e heexo he mic eac ionsandhigh eac ion a es.The eac o
ope a esnea lyadiaba ically,bu he empe a u e isein he eac o canbe
con olled,because hesol en ac sanin e nalcoolingmedium.The
concen a iono hesubs a ede e mines hemaximal empe a u e iseand
he e o e,bycon olling heconcen a ion, hemaximal empe a u e iseis
con olled.In hisway, heamoun o unwan edside‐p oduc scanbe educed.
• Theca alys li emigh beimp o ed.Se e als udiesonisome iza ionand
polyme iza ionp ocessindica e ha indica esupe c i icalsol en scandissol e
cokep ecu so son heca alys su ace,and emo e hembe o e heycan o m
cokeand hisimp o es heca alys li e(Til sche ,1986andSub amaniam,2000).
In oduc ion
26
Sincecoke o ma ionalsooccu sinhyd ogena ionp ocess,i is easonable o
belie e ha ca alys li ecanbeimp o edalso o supe c i ical‐phase
hyd ogena ion.Thismeans educedconsump iono ca alys and educed
p oduc ioncos s.
• Easysepa a iono hep oduc om hesupe c i ical luidjus by educing he
p essu ein he eac o e luen s eam.
• Scalingupis acili a edbecauseo hesingle‐phasecondi ions.Ho spo sand
channellingcanbea oidedand hisleads oabe e selec i i y.
Theeconomyo hewholep ocessseems obe a ou able.Ex emelyhigh olume ic
eac ion a escanbeachie edlead omuchsmalle andcheape plan s.The
concen a iono hesubs a ein hesol en (i.e.loading)isc ucial,asinanyo he
sol en ‐basedp ocess.The eco e yo hesol en ep esen sacon o hep ocess.I is
impo an ha heamoun o sol en isaslowaspossible.Byinc easing hep essu ein
he eac o i ispossible oinc ease heconcen a iono subs a eandin hisway
educes heamoun o sol en ha has obe eco e ed(Hä öde al.,2001).Recen ly
se e alplan sha ebeen akinginope a iondu ing2002:onepilo ‐plan inGö ebo g,
Sweden(Hä ödResea chAB)andoneindus ial‐plan inConse Co.Du ham,Uni ed
Kingdom(ThomasSwan&CoL d).The o me hyd ogena es a yacidme hyles e s
o a yalcohols(10kgalcohols/h,40kgp opane/h,maximump essu e30MPa,andmaximum
empe a u e573.15K)and hela e ,i s i s p oduc wasisopho oneusingCO2as
sol en andPdasca alys .Thedesignedcapaci yo hei plan is1000 on/yea ,i.e.
abou 125kgp oduc /h.
Ano he conis omain ainsingle‐phasecondi ionsinasys emo sol en andsubs a e,
hep essu ehas obeinc easedwhenhyd ogenisadded.Typicalp essu esa e15 o30
MPa.30MPaisconside edasa echnical/economicalmaximump essu e oday.This
means ha o somep ocesses hep essu ein he eac o has obeinc easedcompa ed
o he adi ionalp ocess(Hä ode al.,2001).On heo he hand,30MPaisusedin
some adi ionalp ocesses odayi.e.p oduc iono a yalcohol,and o hesep ocesses
hep essu emigh be educed( andenHa kandHa od,2001).
Rega dingsa e y, he eisnobigaddi ional iskinusinghighp essu esandpossibly
lammablesol en s.The isko usinghighp essu esiscompensa edby hesmalle
olumeo heplan ( isk=p essu ex olume),and heexplosion‐ iskisal eadyp esen
Chap e One
27
inallplan susinghyd ogen.The echnology o handling hesesol en sand iskiswell
knownin hepe ochemicalindus y.
1.4Objec i esandScopeo hisThesis.
Theaimo his esea chis os udycon inuoussingle‐phasehyd ogena iono
sun lowe oilonsuppo edpalladiumca alys susingsupe c i ical luidsasa eac ion
sol en .Thiswouldbeanal e na i ep ocess o p oducingawide a ie yo end
p oduc sha ingdi e en cha ac e is ics(iodine alue, ans‐ a yacidcon en and
sa u a edcon en mainly)o indus ial oods u sin e es obeusedaslowcholes e ol
p ecu so s o ma ga ineandsho eningbasesin henex ewyea s.Inaddi ion, he
objec i eo hes udyis oshow,onalab‐scale, hepo en ialo he e ogeneousca aly ic
eac ionsunde supe c i icalsingle‐phasecondi ions.
Thespeci icaimsa e o:
• Design,buildandpu in oope a ionalab‐scalesupe c i icalhyd ogena ion
plan o ca yingou he eac ionincon inuousmodea highp essu e.
• De e mina iono condi ions o hehyd ogena ionp ocessunde asinglephase
is eallyp esen .The e o e,i isessen ial oknow hephasebeha iou o he
eac i esys emin he egiono in e es in e mso p essu e, empe a u eand
composi ion.
• S udyhow heope a ional a iables ha a ec hesun lowe hyd ogena ion
p ocesswi h ega ds obo h he educ ioniniodine alueand he o ma iono
ansC18:1isome ,pa ame e s ha a enecessa y o u he indus ial ood
applica ionbymeansans a is ical esponse‐su aceme hodologybasedon
expe imen aldesign.Thes udyshouldshow he egionswhe eapo en ialCSTR
p ocesscouldbeope a ed oob ainace ainiodine alueandaminimum ans
C18:1con en .
• Demons a e he easibili yo imp o ing he eac ion a easwellas he
selec i i y o he a sandoilhyd ogena ionwi hcomme cialPdca alys by
educing henumbe o eac i ephasesusingasupe c i ical luidsuchas
p opaneo dime hyle he (DME)asa eac ionsol en .
• Analysiso hes eady‐s a eCSTR eac ion a eda aino de ode e mineo he
kine iccons an s,and hei empe a u edependency, o hemul iple eac ions
In oduc ion
28
o hyd ogena ion–isome iza ionne wo kin ol ing iglyce idespecies.The
kine ic o malism,p oposedea lie o ege ableoilhyd ogena ionsbyAlb igh
(1967)andHashimo oe al.(1971),isused.
• S udy hein apa icledi usi i yo iglyce idesandhyd ogeninsuppo edPd
unde supe c i icalhyd ogena ion eac ioncondi ionsino de ode e mine he
e ec i edi usioncoe icien sin hepo ousca alys pa icle.Theaimis oha e
aninsigh abou hemass anspo mechanismsinpelle s illedwi hSC luid.
Thescopeo hewo kp esen edhe eis hesingle‐phasehyd ogena iono sun lowe
oilonPd/CinSCp opaneinacon inuous ecycle eac o .Fu he wo kwouldin ol e
hede elopmen o apilo ‐scalein eg alpackedbed eac o o ope a ionunde
indus ialcondi ions.Howe e , his allsou side hescopeo hep esen hesis.
1.5ThesisS uc u e.
This hesisisbasedon hema e ialpublishedinse e al echnicalpape sandone
pa en ,whichcanbe ounda heendo he hesis.
Chap e 1consis so abackg oundin oduc ionaimed oexplain heideao use
supe c i ical luidsin hehyd ogena iono a sandoilsand odesc ibe hes a eo he
a andwha a e heaimso his esea ch.
Chap e 2p esen sa heo e icals udy o modelling he apo ‐liquidhighp essu e
equilib ium o sun lowe oil/hyd ogen/C3H8sys emaswellas o sun lowe
oil/hyd ogen/DMEino de ode e minesui ableope a ingcondi ions(concen a ions,
empe a u esandp essu es)necessa y ob ingallhyd ogena ion eac an sand
p oduc sin oahomogeneous eac i e luidphase.
Chap e 3es ablishesabe e unde s andingo howope a ing a iablesa ec he a e
o eac ion,con e sionand inalp oduc dis ibu ioninacon inuous ecycle eac o as
wellas heexpe imen alcondi ionswhe eapo en ialCSTRp ocesscouldbeope a ed
oob ainend‐p oduc swi hindus ial oods u o in e es .Asanex ensiono hese
esul s, hekine icso he eac ioniswo kedou .
Chap e 4i isaconsequenceo he esul so hep e iouschap e andde elops he
s udyo hein apa icledi usion‐ eac ionmechanismsinsupe c i icalsun lowe oil
hyd ogena iononPd/Cca alys .
The inalchap e con ains heexpe imen alde ailso his hesis.
Chap e One
29
Thelas pa ga he s hemainconclusions,discussiono p ospec s o u he
in es iga ionsandp esen s hebibliop aphyand heappendixes.
1.6Nomencla u e.
IV iodine alue[gI2/100goil]:1IV=36molH2/m3oil
P p essu e[MPa]
Pc c i icalp essu e[MPa]
T empe a u e[K]
Tc c i ical empe a u e[K]
Ac onyms
C18:0 s ea ic a yacid
C18:2 linoleic a yacid
C18:3 linolenic a yacid
cisC18:1 oleic a yacid
CSTR con inuouss i ed‐ ank eac o
CO ca bonmonoxide
CO2 dioxideca bon
C3H8 p opane
CP c i icalpoin
DME dime hyle he
EC Eu opeanCommuni y
EU Eu opeanUnion
FAME a yacidme hyles e
In oduc ion
30
FAO FoodandAg icul u eO ganiza iono heUni edNa ions
FDA FoodandD ugAdminis a ion
FT Fishe ‐T opsch
H2 hyd ogen
HDL high‐densi ylipop o ein
IV iodine alue
LDL low‐densi ylipop o ein
Ni nickel
Pd palladium
SC supe c i ical
SCF supe c i ical luid
ansC18:1 elaidic a yacid
TP iplepoin
US Uni edS a es
31
Chap e Two
High‐P essu eEquilib ia.
2.1In oduc ion.
Hyd ogena ionisoneo hemos impo an chemicalp ocesses.Awide a ie yo
chemicalsisob ainedbyhe e ogeneousca aly ichyd ogena ion.Thehyd ogena iono
doublebondsin a sandoilshas hepu poseo p o idingp oduc swi h hedesi ed
mel ingp o ileand ex u e,acco ding o hei inaluse.Thehyd ogena edoilismo e
s ableandlesssensi i e ooxida ion.Theclassicp ocessisca iedou inba ch eac o s
(5–20m3),whe e heoil,hyd ogen,andca alys nickelpowde a emixedin ensi elya
empe a u esbe ween373.15Kand423.15Kandlowp essu es(0.1‐0.3MPa)(Fa au o
andBa holomew,1997).
Thecon en ionaloilhyd ogena ionisca iedou ingas‐liquidphase.A hesu aceo
heliquidoil, hehyd ogengasisinequilib iumwi h heliquidphase(seeCglin
Figu e2‐1).Mos hyd ogena ionca alys sa e e yac i e.Incombina ionwi h hepoo
mass anspo p ope iesin heliquid,la geconcen a iong adien soccu a hegas‐
liquidandliquid‐ca alys in e aces.The eisalsoano he concen a iong adien , om
heca alys su acein o hepo es.Thus,Thelowsolubili yo hyd ogeninoila hese
condi ions, oge he wi h he anspo esis ances,lead olowconcen a iono
hyd ogena heca alys su aceand e ylow eac ion a es.Comme cialoils,whicha e
pa iallyhyd ogena ed,con ainno mally30‐40% ans‐ a yacids(Kinge al.,2000).
Acco ding o hehal ‐hyd ogena ion heo y(Ho iu iandPolanyi,1934), he ans‐ a y
acid o ma ioninc easeswhen hehyd ogenconcen a iona heca alys su ace
dec eases.
The a ou ablesol en and anspo p ope ieso supe c i ical luidsSCFmake hem
anadequa emedium o chemical eac ionsando e g ea oppo uni ies o p ocess
imp o emen (Sa agee al.,1995;Baike e al.,1999).Theapplica iono asui able
supe c i ical luid oagas‐liquidhyd ogena ionp ocesscanb ingall eac an sand
p oduc sin oahomogeneous luidphaseincon ac wi h hesolidca alys a he
equi edmola a ioo he eac an sbychoosingsui ablesol en andsui able
condi ions(concen a ions, empe a u esandp essu es).
High‐P essu eEquilib ia
32
Figu e2‐1:Gene alconcen a ionp o iles o subs a e(‐‐)andhyd ogen(‐‐)inaclassicgas‐
liquidhyd ogena ion.dgl=gas‐liquidin e ace,dlc=liquid‐ca alys in e ace,Cgl=
equilib iumconcen a iono hyd ogeninliquidoil(Hä öde al.,2001).
Thesingle‐phasecondi ionelimina es he anspo esis ancea hegas‐liquidin e ace
(SeeFig.2‐2).This esis anceis he es ic ing ac o in he adi ional ixedbed eac o s.
Compa ed o hegas‐liquidcon en ionalp ocess, hemass anspo esis ancesa e
s ongly educedo comple ely emo ed.The easonsa e he educed iscosi yand he
inc easeddi usi i yin hesupe c i ical luid.Thesingle‐phasecondi ionmakesi
possible o eed heca alys wi hhyd ogeninexcess.Compa ed o hegas‐liquid
eac ion,muchhighe hyd ogenconcen a ionsa heca alys su acea epossible
wi hinasingle‐phase eac ion.This ac leads o e yhigh eac ion a es(Hä ödand
Mølle ,1999,VandenHa ke al.,1999,2001,2001aandMache e al.,1999).
Theconcen a ionp o iles o hesupe c i icalsingle‐phase eac iona esimila o hose
ingas‐phase eac ions.Themaindi e encesa e ha la gemoleculescanbep ocessed
unde easonableconcen a ions,p essu esand empe a u esandanadequa e
empe a u econ ol o exo he michyd ogena ion eac ionsispossibledue o hegood
hea anspo p ope ieso hesupe c i icalsol en .
Chap e Two
33
Figu e2‐2:Gene alconcen a ionp o iles o subs a e(‐‐),hyd ogen(‐‐)andsol en (‐‐‐)
insupe c i icalsingle‐phasehyd ogena ion.d c= luid‐solidca alys in e ace(Hä öde al.,
2001).
Thephasebeha iou , iscosi y,anddensi ya di e en ope a ingcondi ionscan
explainmanyo hee ec so hesol en on he eac ion.Themainbene i so
supe c i icalhyd ogena iona ep ocessin ensi ica ion,smalle eac o sandimp o ed
selec i i ydue o heindependen con olo empe a u e,p essu e,andcomposi iono
he eac an sa heca alys su ace(Hi zle e al.,1998).On heo he hand,due o he
supe io hea andmass‐ anspo p ope ieso supe c i ical luids, heuseo
con inuous eac o sins eado adi ionalba chuni sisallowed.Thelow iscosi yo
he eac ionmediumimp o es heope a iono he eac o and educes hep essu e
d op; helowsu ace ensionalsoassu esabe e we ingo heca alys su acewi hin
he eac ionmix u e.Theuniquesol en p ope ieso supe c i ical luidsgua an ee,in
p inciple,aneasysepa a iono hep oduc s om he eac ionsys em.
Thechoiceo hesol en isno i ial.Theaimo addingasupe c i icalsol en asa
eac ionmediummaybedi e se,e.g. odissol eahea ysubs a e, olimi ca alys
deac i a ion, oimp o eselec i i y,o oenhancemass anspo .The inaldecision
abou sol en selec ionwillalso akein oaccoun o he p ope ies,suchassol en
ine nessa he eac ioncondi ionsandalsoen i onmen alandeconomical
conside a ions.On heo he hand, hephasebeha iou o supe c i icalhyd ogena ion
mix u escanbequi ecomplex.D as icchangesindensi yandsolubili ywi h
empe a u e,p essu e,andcomposi ioncanbeexpec eddue o hep esenceo anea ‐
c i icalo supe c i icalsol en inamix u ewi hpe manen gashyd ogenandhea y
liquidcomponen s.Thela gedi e enceinmolecula sizeand ola ili ybe ween hese
High‐P essu eEquilib ia
40
I iswo hin es iga ing hepossibili y oapplyal e na i esol en s o nea ‐c i icalo
supe c i icalhyd ogena ionp ocesso edibleoils.Ano he po en ialcandida esol en
isdime hyle he ((CH3)2O)(DME).Despi e he ac ha DMEisno allowedasa ood
p ocessingsol en ,i sp ope iesin e na ysys emsasinnea ‐c i icalo supe c i ical
sol en a ecu en lyin es iga ed.DMEmayha ea u u easa eplacemen o engine
uelob ained om ossil ese es.Nowadays,i isusedp ima ilyasap opellan o
sp aycansdue oi highsolubili yinbo hpola andnonpola sol en s,asa uelin
enginesandasa awma e ialin hesyn hesiso ligh ole ins,suchase hyleneand
p opylene(Sa desai,1997).The he modynamics udiesa esca ceandmos o hema e
ela ed o hep oduc iono DME omme hanolbydehyd a a ion(Hansene al.,1995)
andi sapplica ionasp opellan in heae osolindus y(Bohnenn,1981and1986).
Expe imen alda aon hephasebeha iou o hebina ysys emDME/ ipalmi inand
DME/ a yacides e swe e epo edbyFlo ussee al.(1999)andB akee al.(2002)
espec i ely.The mo‐and luiddynamicaspec so hehyd ogena iono iglyce ides
andes e sinp esenceo DMEwe es udiedbyWeidne e al.(2004).
Asmen ionedabo e,supe c i icalhyd ogena ionisdemons ablye ec i eandis
po en iallya ac i ebecause eac ion a escanbeg ea lyinc easedbyusinga
supe c i icalsol en ob ing he eac i ehyd ogena ionmix u ein oasingle
homogeneousphase.This ac p o idesasigni ican ad an ageo hesupe c i ical
p ocesso e con en ionalme hods.Howe e ,amajo ques ioniswhe he asingle
phaseis eallyp esen a heope a ingcondi ions.Whendealingwi ha eac ion
mix u e,a en ionmus bepaidno only o hec i icalpoin so hesinglecomponen s
bu also o hephasebeha iou o hecomple emix u e.On heo he hand, he eisno
enoughda aa ailable o p opaneo DME/hyd ogen/sun lowe oilsys ems o he
pu poseo he eac ions.The e o e, heaimo hischap e is oexplo e hep ope ies
o p opaneandDMEasp omisingsupe c i icalsol en s o single‐phasesun lowe oil
hyd ogena ionbymeanso hes udyo heco espondinghigh‐p essu ephase
equilib ium.
2.2Objec i esandS a egy.
Tos udy heo e ically he apo ‐liquidhighp essu eequilib ium o sun lowe
oil/hyd ogen/C3H8sys emaswellas o sun lowe oil/hyd ogen/DMEsys emino de
ode e minesui ableope a ingcondi ions(concen a ions, empe a u esandp essu es)
whichcanb ingall eac an sandp oduc sin oahomogeneous eac i e luidphase.
Chap e Two
41
Thephaseen elopesha ebeenmodelledusing hePeng‐Robinsonequa iono s a e
(PR‐EOS)alongwi h heone‐ luidVande Waals‐1mixing uleswi h woin e ac ion
pa ame e s:kijno ηij.
2.3Theo e icalDe e mina iono L‐VHighP essu eEquilib ia.
The he modynamicso high‐p essu e apo ‐liquidequilib iais,inp inciple,simila o
ha o hesolubili yo gasesinliquids.Howe e , hegene alconcep sa eno
comple elyuse ul ode e mine heequilib iabecause he ea men conce nsawide
angeo liquid‐phaseconcen a ions,no onlydilu esolu ions.
I ispossible oanaly ically ep esen high‐p essu eequilib iausing o heliquidphase
hecommon he modynamic unc ions:Hen y’scons an ,ac i i ycoe icien andpa ial
mola olume.Howe e ,expe iencehasshown ha in ypicalcases, hese unc ionsa e
no use ul,especially o mul icomponen mix u es.Amo esuccess ul ou e oquan i y
high‐p essu e apo ‐liquidequilib iaisp o idedby he ugaci ycoe icien applied o
bo hphases.
Conside ingabina yliquidmix u ewi hmole ac ionsx1andx2a empe a u eTand
p essu eP;inequilib iumwi h heliquidmix u eanda apo mol ac ionsy1andy2,
heequa ionso equilib iuma e:
11 1111
VL V L
o y x
φ
φ
==(2.1)
and
22 2222
VL V L
o y x
φ
φ
==(2.2)
whe e is he ugaci yandφis he ugaci ycoe icien .Thisin oduces he
composi ionsxiandyiin o heequilib iumequa ions,bu noneisexplici ,because heφi
a e unc ions,no onlyo TandP,bu o hecomposi ion.Thus,equa ions2.1and2.2
ep esen Ncomplex ela ionshipsconnec ingT,P, hexiand heyisui able o
compu e solu ion.
Tocalcula e ugaci ycoe icien s,i canbeusedanequa iono s a e ha is alid o
bo h he apo ‐phasemix u eandliquid‐phasemix u e.Fo eachcomponen iin he
apo ‐phase,weha e:
,,
1
ln ln
V
V
i
VT
iTVn
Vj
PRT PV
dV
RT n V n RT
φ
∞⎡⎤
⎛⎞
⎢⎥
⎜⎟
⎜⎟
⎢⎥
⎝⎠
⎣⎦
∂
=−−
∂
∫(2.3)
High‐P essu eEquilib ia
42
He eniis henumbe o moleso componen iandnTis he o alnumbe o molesin he
apo phase.Simila ly, o eachcomponen iin heliquidphase,weha e:
,,
1
ln ln
L
L
i
LT
iTVn
Vj
PRT PV
dV
RT n V n RT
φ
∞⎡⎤
⎛⎞
⎢⎥
⎜⎟
⎜⎟
⎢⎥
⎝⎠
⎣⎦
∂
=−−
∂
∫(2.4)
whe eniandnTnow e e o heliquidphase.
Touseequa ions2.3and2.4,asui ableequa iono s a eis equi edwhichholds o he
en i e angeo possiblemole ac ionsxandya sys em empe a u eTand o a
densi y angebe ween0and(nT/V)L.Thislas condi ionisnecessa ybecause he
in eg alsgo om heideal‐gass a e(in ini e olume) o hesa u a ed‐ apo and
sa u a ed‐liquiddensi ies.A p esen , he ea enosa is ac o yequa ionso s a e ha
mee hese equi emen swi hgene ali y.Howe e , o manymix u es, he ea e
easonable,app oxima eequa ionso s a e ha p o ideuse ul esul s.
Thesimples p ocedu e o usingequa ions2.3and2.4is ochooseanequa iono s a e
ha holds o pu e luid1and o pu e luid2and oassume ha hissameequa iono
s a eholds o allmix u eso 1and2byin e pola ion.
Themos commonlyusedcubicEOSsa e hePengRobinson(PengandRobinson,1976)
and heSoa e‐Redlich‐Kwong(Soa e,1972)equa ions.Theyp oduceessen ially
equi alen esul ssincebo hequa ionsa ecubicin olume.ThePRequa ionis:
()
()()
RT a T
P b b b b
=−
−++−
(2.5)
whe e is hemola olume,aaccoun s o in e molecula in e ac ionsbe ween he
speciesin hemix u e,andbaccoun s o sizedi e encesbe ween hespecieso he
mix u e.PengandRobinsongi e he ollowingp esc ip ions o aandb:
0.07780 C
C
RT
bP
⎛⎞
=⎜⎟
⎝⎠
(2.6)
() ( )( , )
CR
aT aT T w
α
=(2.7)
22
( ) 0.45724 C
C
C
RT
aT P
=(2.8)
Chap e Two
43
1/2
1((1 )mT
α
=+ − (2.9)
2
0.37464 1.54226 0.26992mww=+ − (2.10)
10
0.7
1.000 log
R
sa
CT
P
wP=
⎛⎞
=−
⎜⎟
⎝⎠(2.11)
whe eTCis hec i ical empe a u e,PCis hec i icalp essu e,TRis he educed
empe a u e(TR=T/TC),andwis heacen ic ac o o componen i.Eacho hesepu e
componen p ope ies,including heacen ic ac o ,canusuallybe oundin he
li e a u e o mos o hecommonlow‐ o‐mode a emolecula weigh hyd oca bons
(Reid,P ausni zandPolling,1987).
Whendealingwi hgasandliquidmix u es,i isnecessa y ode inecombining ules o
amixandbmix ouse heequa iono s a eino de ocalcula emix u ep ope ies.In his
de elopmen i willuse heso‐called ande Waals‐1mixing ules ha assume andom
mixingo hecomponen s.Theseequa ionsa eusedonce o hegasphasemix u eand
once o heliquidphasemix u e.
mix i j ij
ij
axxa=
∑
∑(2.12)
0.5
()(1)
ij ii jj ij
aaa k=−
(2.13)
mix i j ij
ij
bxxb=
∑
∑(2.14)
()
(1 )
2
ii jj
ij ij
bb
b
η
+
=−(2.15)
whe ekijandηija emix u epa ame e s,usuallyde e minedby i ingp essu e‐
composi ionda a,andxdeno esei he liquido gasphasemole ac ion.Wi h hese
mixing ules, heanaly icalexp essionob ained o he apo phase ugaci ycoe icien
o componen iis:
High‐P essu eEquilib ia
44
* *
22.414
ln 1 ln ln
2.828 0.414
V
jij
VV j
Vi i
iV
mix mix mix
P
xa B
bbP P A RT
BP
bRT RT Ba b B
RT
φ
⎛⎞
⎛⎞
+
⎜⎟
⎛⎞⎛ ⎞ ⎜⎟
=−−−− −
⎜⎟
⎜⎟⎜ ⎟ ⎜⎟
⎝⎠⎝ ⎠ ⎜⎟
⎜⎟
−
⎜⎟
⎝⎠
⎝⎠
∑
(2.16)
whe eamixandbmixa ede e minedusing2.12 h ough2.15wi h hegasphasemole
ac ions,andAandBa e:
22
mix
aRT
AP
=(2.17)
mix
bRT
BP
=(2.18)
The e mbi*isde inedas:
*
,,
() 2
ji
mix
i K ik mix
k
iTVn
bN
bxbb
N≠
⎡⎤
∂
==−
⎢⎥
∂
⎣⎦ ∑(2.19)
whe eNis he o alnumbe o molesin hemix u eandxdeno esei he liquido gas
phasemole ac ions.Theanaly icalexp essionob ained o heliquidphase ugaci y
coe icien o componen iissimila oequa ion2.16:
**
22.414
ln 1 ln ln
2.828 0.414
L
jij
LL j
Lii
iL
mix mix mix
P
xa B
bbP P A RT
BP
bRT RT Ba b B
RT
φ
⎛⎞
⎛⎞
+
⎜⎟
⎛⎞⎛ ⎞ ⎜⎟
=−−−− −
⎜⎟
⎜⎟⎜ ⎟ ⎜⎟
⎝⎠⎝ ⎠ ⎜⎟
⎜⎟
−
⎜⎟
⎝⎠
⎝⎠
∑
(2.20)
Nei he kijno ηija eexpec ed obe unc ionso empe a u e,p essu e,o composi ion.
No mally,bo ha eexpec ed oha eabsolu e aluemuchless han1.0.Thepa ame e
kijisabina ymix u epa ame e associa edwi h hein e molecula in e ac ions
be weenapai o unlikespecies.The alueo hispa ame e usually angesbe ween‐
0.1and0.15.I canalsobenega i e,al houghanega i e alueusuallyindica es he
p esenceo speci icchemicalin e ac ions,suchashyd ogenbonding.I isques ionable
whe he anEOSapp oachshouldbeusedwhencalcula ing hep ope ieso amix u e
ha hascomponen s ha hyd ogenbond,becauseacubicEOSaccoun sonly o
dispe sion o cesbe ween hemix u ecomponen sandno o chemical o ces.Also,a
di e en se o mixing ulesisneeded o amixandbmixsince hecomponen sa eno
expec ed odis ibu e andomlyinsolu ioni heycanhyd ogena ebonds.
Thebina ymix u epa ame e ηij, ypicallyasmallnega i enumbe ,isassocia edwi h
hepackingo unlikecomponen s.Many imesi ismo eexpedien ose ηijequal o
ze oespeciallyi onlyalimi edamoun o da aisa ailable.I ηijisse equal oze o, he
Chap e Two
45
mixing ule o bmix educes oasinglesumma ioninmole ac ion,bi*becomesequal o
bi,and heequa ion o he ugaci ycoe icien o componen i educes o heo iginal
exp essiongi enbyPengandRobinson(1976).Howe e ,Dei e sandSchneide (1976)
ha e ecommended ouse heRedlich‐Kwongequa ion.Theyha ecalcula edP‐x
iso he msandc i icalmix u ecu es o sys ems ha ha ec i icalmix u ep essu es
(McHughandK ukonis,1994).
Fo ypicalcalcula ionsi iscon enien oexp essphase‐equilib ium ela ionsin e ms
o K alueso equilib ium a ios.Thede ini iono Khasno he modynamic
signi icancebu Kiscommonlyusedinchemicalenginee ingcalcula ionswhe ei is
con enien o w i ingma e ialsbalances.AK alueissimply heequilib ium a ioo
he apou oliquidcomposi ion.The e o e, heequilib ium a ios(K ac o s)a egi en
by
11
1
11
L
V
y
Kx
φ
φ
==(2.21)
22
1
22
L
V
y
Kx
φ
φ
==(2.22)
Tocalcula e heequa iono s a eo high‐p essu e apou ‐liquidequilib ia, he
compu a ionalp ocedu eisno i ial.Ina ypicalcase, hegi enquan i ies o a
bina ymix u emaybePandx1(andx2).Equa ions2.1,2.2,2.3and2.4mus henbe
used o indT,y1(andy2).Howe e , ouse2.3and2.4 hemola olumes Vand Lmus
beknown.Ino de ode e mine hesepa ame e s, heequa iono s a e o hemix u e
(say,equa ion2.5)isapplied wice,once o he apou mix u eandonce o heliquid
mix u e.
As a as hebina ysys emisconce nedhe e, he ea e ou unknowns:y,T, Vand L.
To ind hese,i isnecessa y osol esimul aneously ou independen equa ions.
Equa ions2.1and2.2[wi hequa ions2.3and2.4subs i u ed o he ugaci y
coe icien s]and2.5 wice(once o eachphase)canbeemployed.Asimila p ocedu e
isused o mul icomponen mix u es(P ausni ze al.,1986).
2.4Resul sandDiscussion.
Theapplica iono a he modynamicmodelinphaseequilib iumcalcula ions equi es
heknowledgeo pu ecomponen sp ope iesand hein e ac ionpa ame e sbe ween
High‐P essu eEquilib ia
46
componen s.Since ege ableoilsa ecomplexmix u eso iglyce ideswi h a yacids
con ainingdi e en chainleng handdeg eeo sa u a ion,i sphysicalp ope iessuch
as apo p essu es,c i icalp ope ies,acen ic ac o ,e c.a eno alwaysa ailable.
Thus,i wasnecessa y omakea oughes ima iono hemacco ding o heChueh–
P ausni zapp oxima ion(Reide al.,1987)(seeAppendixC).Fo heo he componen s,
hyd ogen,p opaneandDME, hephysicalp ope iesa ep esen edinTable2‐3.
Table2‐3:Physicalp ope yda a o hyd ogena ionspecies(Yaws,1999).
CompoundMolecula
Weigh (g/mol)Tc(K)Pc(MPa)Vc
(cm3/mol)w
Sun lowe *
Oil875859232611.730
P opane
(C3H8)44.01370.34.24202.90.153
Hyd ogen
(H2)2.0233,181.3164.2‐0.22
DME
(C2H6O)46.07400.15.37168.80.204
*Thephysicalp ope yda a o sun lowe oilwases ima edinAppendixC.
Thebina y apo ‐liquidequilib ia(VLE) o hesys emssun lowe oilinC3H8and
DMEwe emodelledin e mso VLEcons an sasa unc iono p essu ea cons an
empe a u e(Ramí eze al.,2002).TheVLEcons an swe ecalcula ed o bo hsys ems,
es ima ing heequilib ium a ios(Ki) alues om he ugaci ycoe icien scalcula ed
wi h hePR‐EOS(McHughandK ukonis,1994;Sandle ,1999).Fo mo ede ailssee
AppendixD.Thecalcula ionswe epe o medin e mso hecon e gencep essu e
(Hougene al.,1954).Thebina ypa ame e skijandηijwe ese oze oassugges edby
B unne (1994)whenexpe imen alphaseequilib iumda aonna u alp oduc ‐SCF
mix u eissca ce.The eisnoexpe imen alin o ma ionin heconcen a ion egiono
in e es o homogeneoushyd ogena ion.
The apo ‐liquidequilib iumwasp edic ed o C3H8/sun lowe oilsys ema 400,450
and473KasshowninFigu e2‐6.
Figu e2‐7p esen s he apo ‐liquidequilib iump edic ed o DME/sun lowe oila
453,474,523.15and573.15K espec i ely.
Chap e Two
47
0.000001
0.00001
0.0001
0.001
0.01
0.1
1
10
100
0.1 1 10 100
P (MPa)
K1, K2
K2
400K
450K
483K
0.001
0.01
0.1
1
10
100
0.1 1 10 100
P (MPa)
K1, K2
453 K
473 K
523 K
573 K
K1
K2
Figu e2‐6:VLEin hec i ical egion o hebina ysys emp opane(1)‐sun lowe oil(2)
( apo iza ioncons an scalcula edwi hPR‐EOS)(Ramí eze al.,2002).
Figu e2‐7:VLEin hec i ical egion o hebina ysys emDME(1)‐sun lowe oil(2)
( apo iza ioncons an scalcula edwi hPR‐EOS).
High‐P essu eEquilib ia
48
Despi eo he ac ha hisisanapp oxima ees ima ion, hep opane–oilbina y
mix u eexhibi sacon e gencep essu ea a ound14MPa,whe eas hesys emwi h
DMEins eado C3H8hasacon e gencep essu ea a ound10MPa.The e o e,wi h
espec o he eac o ope a ingp essu e,i wouldbelessexpensi e ouseDME a he
hanp opane.
Acompa isono heK alues o dime hyle he wi h hep edic edda a o p opane o
heiso he m473.15Kwases ablishedinFigu e2‐8.
0
6
12
18
0.1 1 10 100
P essu e (MPa)
K1
P opane
DME
Figu e2‐8:K‐ alues o DMEin heDME/sun lowe oilsys emand o p opaneinp opane
/sun lowe oilsys ema 473.15K.
InFigu e2.8, heK alues o dime hyle he a elowe han hose o p opanebecause
p opanehasahighe apo p essu e hanDME.Thepola na u eo dime hyle he
seems obemo ecompa iblewi hsun lowe oil hanp opaneowing o he ac ha
ege ableoilswhichmainlyconsis o mix u eso iglyce ideswi hlong‐ a yacid
chainsa econside edsligh lypola molecules(Fo na ie al.,2001).Besides,pola i y
playsamajo oleinmaking hemo epola sol en mo esolublein hehyd ogena ion
subs a easshows heFigu e2‐9 epo edbyPe edae al.(2003).
Chap e Two
49
Figu e2‐9:VLEandLLEo iglyce ideswi hsol en sa a educed empe a u eo 1.05.
Expe imen al:●Bha a he al.1992;▪Coo ense al.1988;◊Flo ussee al.2002;‐Pe edae
al.p edic ions(2002).Figu e aken omPe edae al.(2003).
I becomesclea om he igu ep esen edabo e ha ca bondioxideisno agood
sol en o hesupe c i icalhyd ogena iono a sandoils,because he egiono pa ial
miscibili yex ends o e yhighp essu es.Howe e ,o he sol en s,suchasdime hyl
e he andp opane,achie ecomple emiscibili ya mode a ep essu es.
The apo ‐liquidequilib ium o p opane/hyd ogen/sun lowe oiland
DME/hyd ogen/sun lowe oil e na ysys emshasbeenmodelledwi h hePR‐EOS
usingHYSYS2.4.1Build3870(Hyp o ech,USA).Theso wa ep o ides he
composi ion o eachcomponen in heliquidand apo phases espec i ely,aswellas
he o al apo ac ion.Thecu eo bubblepoin sis eachedwhen he ac iono
apo isnulland hecu eo dewpoin swheni is1.To ind hesepoin s, hep essu e
and empe a u ewe ese cons an and hecomposi iono he e na ymix u ewas
a ied.Fo eachpoin ,sol en composi ionwasse cons an and he es o he
composi ionwas a iedun il he o al apo ac ion eachedei he 0o 1 alue.A e
ha , hep ocedu ewas epea edwi ho he p opanecomposi ionsino de obuild
bubbleanddewcu es(Fo mo ede ailsseeAppendixE).
Fi s o all, heVLEes ima ionme hodwasp o edwi hH2‐cyclododeca iene(CDT)‐
CO2sys emusing heexpe imen alda a omE axiase al.(2001)a 423.15Kand20
MPaandwi h he e na yhyd ogen‐p opane‐ ipalmi inmix u ea p essu eo 439.15
Kand12MPa epo edbyRo e oe al.(2001)(seeFigu e2‐10).Fo bo hsys emsunde
High‐P essu eEquilib ia
56
heone‐ luid ande Waalsmixing uleswi hkijandηijasbina yin e ac ion
pa ame e s.
Thecapabili yo PR‐EOS o ep esen hephase‐equilib iumcondi ionsinse e al
mix u eswasp e iouslys udied,basedonexpe imen alda a om heli e a u e
(E axiase al.,2001andRo e oe al.,2001).Agood ep esen a iono hese
expe imen alda awasob ained(a ela i ee o o 8%in hewo s case).
TheVLEp edic ions o sun lowe oil/H2/C3H8andsun lowe oil/H2/DME e na y
sys emsalongwi hexpe imen alVLEconside a ions omo he esea che s,whoha e
wo kedonsimila eac i esys ems,we eemployed o de e miningsui ableope a ing
condi ions(concen a ions, empe a u esandp essu es) ha couldassu eall
hyd ogena ion eac an sandp oduc swe ein oahomogenous eac i e luidphase.
La e expe imen al unsallowed ocon i m ha auniquesupe c i icalsingle‐phasewas
p esen edin o he eac o unde chosenope a ingcondi ionsbymeanso checkingoil
ma e ialbalanceaswellasmoni o ing he a eo eac ion.
2.6Nomencla u e.
aVande Waalspa ame e ha accoun s o in e molecula in e ac ions
be weenspeciesin hemix u e[(Pam6/mol2]
bVande Waalspa ame e ha accoun s o sizedi e encesbe ween he
specieso hemix u e[m3/mol]
Cgl equilib iumconcen a iono hyd ogeninliquidoil[cm3/mol]
d c luid‐solidca alys in e ace
dgl gas‐liquidin e ace
dlc liquid‐ca alys in e ace
ugaci y[MPa]
k12 pa ame e o bina ymix u e
Ki VLEcons an .Ki=yi/xi,whe ei=1 o SCFandi=2 o sun lowe oil
MR mola a iohyd ogen/subs a ein he eac i emix u e
MW molecula weigh [kg/mol]
Chap e Two
57
N o alnumbe o molesin hemix u e
ni numbe o moleso componen i
nT o alnumbe o molesin he apo phase
P p essu e[MPa]
Pc c i icalp essu e[MPa]
PR educedp essu e.PR=P/Pc
Psa sa u a ionp essu e[MPa]
R gas‐lawcons an [8.314J/(molK)]
T empe a u e[K]
Tc c i ical empe a u e[K]
TR educed empe a u e.TR=T/Tc
mola olume[m3/mol]
V olumeo hemix u e[m3]
w acen ic ac o
x liquidmol ac ion,whe ei=1 o SCFandi=2 o solu e
y apo mol ac ion,whe ei=1 o SCFandi=2 o solu e
G eekle e s
η12 pa ame e o bina ymix u e
φ ugaci ycoe icien
∞ in ini edilu ion
High‐P essu eEquilib ia
58
Ac onyms
CO2 dioxideca bon
C3H8 p opane
DME dime hyle he
EOS equa iono s a e
FAME a yacidme hyles e
H2 hyd ogen
PR Peng‐Robinson
VLE apou ‐liquidequilib ium
Sub‐andSupe c ip s
1 ola ilecomponen (ligh )
2 non‐ ola ilecomponen (hea y)
c c i ical
i componen
L liquidphase
mix mix u e
R educed
sa sa u a ion
V apo phase
59
Chap e Th ee
Kine icso heSun lowe OilHyd ogena ionP ocesso e
Palladium‐BasedCa alys susingSCp opaneo SCDMEas
Reac ionSol en .
3.1In oduc ion.
Thechemis yo hyd ogena ion eac ionsiscomplexasbo h hemono‐ andpoly‐
unsa u a edacidg oupsin heoilhyd ogena ea di e en a es,dependingon he
ope a ingcondi ions.Fu he mo e,geome icalands uc u alisome iza iono double
boundscanoccu ,and hishasanimpo an e ec on hephysicalp ope ieso he
inalp oduc s(Pa e son,1983).
The i s mechanis ickine icmodel o ege ableoilhyd ogena ionwasde elopedby
Bailey(1949)whop oposed he ollowingschemeo eac ionso heunsa u a ed
iglyce ides o heba chhyd ogena iono linseed,soybeanandco onseedoil.
Scheme3‐1:Kine icmodel o oilhyd ogena ionde elopedbyBailey(1949).
Using hismodel,Baileyconside edeach eac ion obe i s o de andi e e sibleand
husde eloped hekine icsequa ions o ep esen heconcen a iono eachacidg oup
asa unc iono imeaswellasde e mined hee ec o ope a ing a iablesonp ocess
selec i i y,iso‐oleicacid o ma ionandhyd ogena ion a e.Theinc easeo
empe a u e,hyd ogenp essu e,nickelca alys concen a ionandagi a ioninc ease he
eac ion a ewhe easselec i i yandisome iza ionis a ou eda highe empe a u e
andca alys concen a ionaswellasa lowe p essu eandagi a ion.
The e m“selec i i y”applied ohyd ogena ion eac ionhad womeaningsin he
indus y.O iginally, he e mwasde inedbyRicha sone al.(1924)as hecon e siono
linoleicacid oamonoene,compa ed o hecon e siono hemonoene os ea icacid.
Thiswasalsoknownaschemicalselec i i ysincei compa ed he a eso chemical
eac ions.Ano he ypeo “selec i i y”wasapplied o heca alys .I aca alys was
Linolenic
Linoleic
Isolinoleic
OleicS ea ic
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
60
“selec i e”,i p oducedanoilo so e consis encyo lowe mel ingpoin a agi en
IodineValue(IV).
F om ela i e eac ion a econs an scalcula ed o se e al unsbyBailey, heselec i i y
( a io)o he eac ionwasde inedas he a ioo he eac ion a econs an o linoleic o
oleic,di idedby he eac ion a econs an o oleic os ea ic.I he a iowas31o
abo e, hehyd ogena ionwasselec i eandbelow7.5,non‐selec i e.Ideally,selec i i y
a io(SR)shouldbela ge,sincep oduc iono oleicacidisdesi ed,whilei s u he
eac ion osa u a eds ea icacidisundesi able.
ElbidandAlb igh (1957)p oposedane wo ko chemical eac ions(see heschemeas
ollows) o co onseedoilhyd ogena ion akingin oaccoun hep esenceo ans
con igu a ionso hedoublebondsbecauseo hei s ongin luenceon heso ening
poin andconsis encyo he inalp oduc .
Scheme3‐2:Kine icmodel o co onseedoilhyd ogena ionbyElbidandAlb igh (1957).
I wasassumed ha eacho he eac ionswasi e e sibleandpseudo‐ i s o de .They
p oposedamechanism o selec i i ybasedonp e e en ialphysicaladso p iono
linoleicins eado oleicacidon heca alys su aceaswellason heassump ion ha he
a e‐con ollings epis hesu ace eac ionbe weena omicallychemiso bedhyd ogen
andphysicallyabso bedunsa u a edassugges edbe o eBoelhouwe e al.(1950),
K ane(1953)andAllenandKiess(1956).
ElbidandAlb igh ’s esea ch ocussedon hee ec o heope a ing a iablesas
empe a u e,p essu eandconcen a iono henickelca alys on hehyd ogena ion
a eandselec i i yo e awide angeo expe imen alcondi ionsbu heyapplieda
igo ousagi a ionino de ominimize/elimina emass ans e esis ances.Fo ha
eason, hei expe imen al esul swe equi edi e en ha hoseob ainedbyo he
esea che s(e.g.Moo e(1917),Richa sone al.(1929)andBailey(1949))whoused
ela i elylowdeg eeso agi a ion.Theo e all a eo hyd ogena ionwasdi ec ly
p opo ional o empe a u e,p essu eandca alys concen a ion.Ali lechangein
selec i i ywas oundwi h empe a u ewhilesligh lymo eiso‐oleicacidwas o meda
Linoleicacid
k1
k2
cis‐Oleicacid
Iso‐Oleicacid
k3
k4
k5
S ea icacid
Chap e Th ee
61
high empe a u e.Bo hselec i i yandisome iza iondec easedwi hinc easedp essu e
whe easca alys concen a ionhadnosigni ican in luenceon hem.
Becausemos o he o me hyd ogena ions udieso iglyce ideshadbeena ela i ely
lowp essu e(up oabou 1MPa),WisniakandAlb igh (1961)ca iedon he
hyd ogena iono co onseedoilapplyingmode a ehyd ogenp essu esino de o
cla i y he eac ionmechanism.Theymade hesameassump ionsexplainedabo e.
Simila esul sas hose epo edbyElbidandAlb igh (1957)we eob ainedbu hey
disco e ed ha heo e all a eo hyd ogena ionwasp opo ional o hesys em
p essu e o hepowe o 0.6.
Asimple eac ionsequencewasp oposedbyAlb igh (1965).Since helinolenicacid
p oducesse e aldi e en dienes(isolinoleicacids)whenonedoublebondis
hyd ogena edandsince he ewouldbeli ledi e encein he a eso hyd ogena iono
hemix u eo dienes, hesewe eincludedinone e m.Also,since headdi iono wo
moleso hyd ogen olinolenicacid op oduceoleicaciddi ec lyhasno beenshown o
occu , heshun waselimina ed om hemodel,andsincegeome icandposi ional
isome s ha a e o medwe ebelie ed oha ealmos hesame eac i i y, hesewe e
no includedin hemodel.Thus hemodelissimpli ied o:
3
12
k
kk
Linolenic Linoleic Oleic S ea ic acid⎯⎯→ ⎯⎯→ ⎯⎯→
Scheme3‐3:Kine ic eac ionsequence o oilhyd ogena ionbyAlb igh (1965).
k1,k2andk3a e he eac ion a econs an sand hemodelassump ionswe eachemical
eac ionsequenceo i s o de ( he eac ion a edependson heconcen a iono
unsa u a edacids),i e e sible“elemen a y”s epsand ha H2isp esen inla ge
excess.Va iousselec i i y a iosha ebeende i ed om hiskine icscheme:
2
3
()
I
k
Linoleic Selec i i y S k
=
(3.1)
1
2
()
II
k
Linolenic Selec i i y S k
=
(3.2)
He eSIandSIIexp ess hep e e edsa u a iono doublebondsindieneso e
monoenesand ieneso e dienes, espec i ely.Mos comme cialnickelca alys sunde
hecondi ionsused o nickelcomme cialhyd ogena ions(0.3MPa,423.15‐498.15K)
ha eanSIo 30‐90.Ingene al,ahyd ogena ionca alys is hough obeselec i ei SIis
highe han10.
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
62
The eac ion a es o hemechanismp esen edabo ewe e ound obepseudo‐ i s
o de wi h espec o heoil iglyce idesbyBe ne al.(1975),Snyde e al.(1978),Chen
e al.(1981)andAllen(1981).On heo he hand,se e alau ho s ounda i s ‐o de
eac ion a ewi h espec o hehyd ogenconcen a ion(e.g.ElbidandAlb igh (1957),
WisniakandAlb igh (1961),Ma angozise al.(1977))
Usingasimila simpli iedkine icschemebyAlb igh (1965),Co do aandHa io
(1975)ha es udied hehyd ogena iono me hyllinolea eusing1%Pdonca bonasa
ca alys .The eac ionkine icso he i s s ep(i.e.linolea e oolea e)wass udiedusing
heini ial a eda awhe enos ea a eis o med.Simila ly, hekine icso hesecond
s ep(i.e.olea e os ea a e)wass udiedusing heda ain he egionwhe e helinolea e
iscomple ely eac ed.They ound he i s eac ion obe i s ‐o de and hesecond
eac ion obehal ‐o de wi h espec ohyd ogen.
Thehyd ogena iono me hyllinolea e ome hylolea eandme hyls ea a ewass udied
inas i edba ch eac o usingse e alpa iclesize ac ionso 1%Pd/Cca alys by
Tsu oe al.(1978).Using he“con en ional” eac ionscheme(seeScheme3.3), hey
ound ha hehyd ogena ionso bo hsubs a eswe e i s o de wi h espec o
hyd ogen,whichdidno comple elyag eewi hCo do aandHa io (1975),bu some
o helinolea eappea ed o eac di ec ly os ea a e(shun eac ion)pe hapsbecauseo
nonequilib iumadso p iono eac an s.
ThemodelusedbyAlb igh (1967)(seechemicalschemep esen edas ollow)was
ound obeapplicable o hehyd ogena iono co onseedoilbyHashimo oe al.
(1971)using heexpe imen alda a omEldibandAlb igh a lowp essu e(1957)and
ha omWisniakandAlb igh (1961)a highp essu einwhich hemass ans e
e ec swe eessen iallyelimina ed.
Scheme3‐4:Kine icmodel o co onseedoilhyd ogena ionbyAlb igh (1967).
Hashimo oe al.(1971)p oposed i s ‐o de a eequa ionswi h espec o he
composi ionso he a iousliquidcomponen sin heliquidphase.B,R1,R2andS
ep esen di‐unsa u a ed,cis‐mono‐unsa u a ed, ans‐mono‐unsa u a edandsa u a ed
R1
B
k’12
k’13R2
k’23
k’24
k’34
S
k’32
Chap e Th ee
63
a yacidg oups, espec i ely.The(ki,j)’sa e he espec i epseudo i s ‐o de eac ion
a econs an sinwhich hee ec o hyd ogenp essu eisincluded:
ʹ1/2
12 12 2
H
kkC
=
(3.3)
ʹ1/2
13 13 2
H
kkC
=
(3.4)
ʹ1/2
23 23 2
H
kkC
=
(3.5)
ʹ1/2
32 23 2
(/3)
H
kkC
=
(3.6)
ʹ
24 24 2
H
kkC
=
(3.7)
ʹ
34 34 2
H
kkC
=
(3.8)
Ino de odec ease henumbe o pa ame e s osol ein his eac ionscheme,i was
assumed ha k’32=k’23/3,basedonequilib ium a ioo hecis/ anso mono‐unsa u a es
epo edbyse e alau ho se.g.Li ch ielde al.(1963)andAlb igh (1967),andk’24=k’34
sugges ing ha he a eso hyd ogena ion o hemono‐unsa u a ed a yacidg oups
a ealmos equal.
Thede ailed eac ionmechanism,whichexplained hiskine icbeha iou ,sugges s ha
hyd ogena omswe e o medby hedissocia iono hyd ogenmoleculeson heca alys
su ace.Basedon hebasicconcep so AllenandKiess(1956), he esea che sha e
assumed ha asingleac i a edhyd ogena oma ack hedoublebond oyieldan
uns ablepa iallyunsa u a edcomplex.I heconcen a iono hyd ogena omishigh
on heca alys su ace, hecomplexwillp obably eac wi hano he hyd ogena om o
comple e hesa u a ionand hus hehyd ogena ionoccu s.On heo he hand,in he
opposi ecase, hecomplexwilldecompose o e o madoublebond.Howe e his
doublebondmaybein heo iginalposi iono in headjacen posi ionbecauseei he o
hehyd ogenadjacen o he ee adicalcen emaybe emo ed.Since hecomplex
mayob ain ee o a ion, hesubsequen emo alo ahyd ogena om esul sin he
p oduc iono aciso ansdoublebond.Thecomple edmechanismisp esen edas
ollows:
222
kA
kA
HH
σ
σ
−
⎯⎯⎯→
+←⎯⎯⎯(3.9)
kB
kB
BB
σ
σ
−
⎯⎯→
+←⎯⎯ (3.10)
0
0
k
k
BH BH
σ
σσσ
−
⎯⎯→
++
←⎯⎯ (3.11)
1
1
11
1
2
kR
k
kR
BH H R R
σ
σσσ σ
−
⎯⎯⎯→
+⎯⎯→+ +
←⎯⎯⎯(3.12)
2
2
22
21
2
kR
k
kR
BH H R R
σ
σσσ σ
−
⎯⎯⎯→
+⎯⎯→+ +
←⎯⎯⎯(3.13)
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
64
3
13
k
k
RH RH
σ
σσσ
−
⎯⎯→
++
←⎯⎯ (3.14)
4
24
k
k
RH RH
σ
σσσ
−
⎯⎯→
++
←⎯⎯ (3.15)
52
kS
k
kS
RH H S S
σ
σσσ σ
−
⎯⎯→
+⎯⎯→+ +
←⎯⎯ (3.16)
σ ep esen sanunoccupiedac i ecen eon heca alys su ace.Hσ,Bσ,R1σ,R2σand
Sσ e e o headso bed o mso hyd ogen,di‐unsa u a ed,cis‐mono‐unsa u a ed,
ans‐mono‐unsa u a edandsa u a edacidg oups espec i ely.BHσ isanadso bed
complex ha is o medbya acko ahyd ogena om ooneo he wodoublebondso
di‐unsa u a ed a yacidg oupsB,andRHσ isanadso bedcomplex o med om
mono‐unsa u a edacidg oupscon ainingbo ho hecisand anscon igu a ions.
In heabo emodel,allposi ionalisome iza ionsandgeome icalisome iza ions eps
a eno akenin oaccoun becauseo hei complexi ies.Theyassumed ha adso p ion
anddeso p ions epsa equilib ium, heca alys su aceisspa selyco e edby
adso bedcomponen sand hus heconcen a iono unoccupiedsi esisessen ially
independen o heconcen a ionin heliquidphaseand he a eequa ionsapply o he
imeelapseda e heinduc ionandalso ha in apa icledi usionalg adien sa e
negligible.The ollowing es ic ionsamong he a econs an swe eheld:
012 2
()
AH
kkkKC
−+(3.17)
34 5 2
() AH
kk kKC
−−
+(3.18)
Unde heassump ionsmen ionedabo e, he a econs an s o hes oichiome ic
cons an skijwe ede inedas:
[
]
2
12 1 0 2 1 2
/
()
BA
kkk KKkk
σ
=+(3.19)
[
]
2
13 2 0 2 1 2
/
()
BA
kkk KKkk
σ
=+(3.20)
[
]
2
23 3 4 2 3 4
1
/
()
RA
kkk KKkk
σ
−−−
=+(3.21)
[
]
2
32 4 3 2 3 4
2
/
()
RA
kkk KKkk
σ
−−−
=+(3.22)
[
]
2
24 5 3 2 3 4
1
/
()
RA
kkk KKkk
σ
−−
=+(3.23)
[
]
2
34 5 4 2 3 4
2
/
()
RA
kkk KKkk
σ
−−
=+(3.24)
ʹ
A
A
A
k
Kk−
=(3.25)
ʹ
B
B
B
k
Kk−
=(3.26)
Chap e Th ee
65
1
1
ʹ
1
R
R
R
k
Kk−
=(3.27)
2
2
ʹ
2
R
R
R
k
Kk−
=(3.28)
ʹ
S
S
S
k
Kk−
=(3.29)
K ep esen s headso p ionequilib iumcons an s,ki he a e o espec i eelemen a y
eac ionand[σ2]is heconcen a iono ac i esi eson heca alys su ace.
Theseau ho sconcluded om heanalysiso hei hyd ogena ion esul s ha he a e
o hyd ogena ion o di‐unsa u a ed a yg oups omono‐unsa u a edand he a eo
hegeome icalisome iza ionsbe weenmono‐unsa u a edwe ehal o de wi h espec
ohyd ogenconcen a ion,whe eas hehyd ogena ion a eo mono‐unsa u a ed o
sa u a edg oupswas he i s o de .
Owing o hedis inc physico‐chemicalp ope ieso hecisand ansisome salso,
ano he ypeo selec i i ywasde inedbyCoenen(1976).TheSpeci icIsome iza ion(Si),
gi es henumbe o ansdoublebond o medpe doublebondhyd ogena ed.Aswell
asmos o hehyd ogena ion esea che s,hes udied hein luenceo p ocesscondi ions
ondissol edhyd ogenconcen a ionnea ca alys su aceandonselec i i iesSIandSi
and oundsimila esul s o hose epo eda ela i elylowdeg eeso agi a ion.
Meanwhile,Coenende e mined hee ec o po ewid honselec i i yasshowsin
Figu e3‐1.
Acco ding o hezoneA, hepo ewid hismuchbigge han hesizeo iglyce ide
molecules.The e o e,oilandhyd ogencangomo e eelyinandou wi hou much
hind ance.In hissi ua ion,hyd ogena ion a ou s hemos unsa u a ed a yacids.In
po eso mediumwid h,apoin willbe eachedwhe e hepoly‐unsa u a edwillbe
almos ullyhyd ogena ed.In hiszone(zoneB), hehyd ogena iono mono‐
unsa u a ess a s ooccu .Finally,inpo eswhe e heaccessishighly es ic ed(zone
C),i exis sasemi‐s agnan popula iono ullyhyd ogena edma e ial.
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
72
Inap e iouswo k(Ramí ezandLa ayoz,2002),wep esen edp elimina y
expe imen alda a omacon inuous,single‐phasehyd ogena iono sun lowe oilon
Pd/Cca iedou inaRobinson‐Mahoney ypeo eac o ,wi ha ixedbedca alys using
p opaneasSCsol en .The esul sshow ha i ispossible op edic he o ma iono
se e alhyd ogena ionp oduc swi hce aincha ac e is ics o di e en indus ial
applica ionsbychanging heope a ingcondi ions,since he inalp oduc dis ibu ion
dependson empe a u e,p essu eand eedmix u ecomposi ion.
Thoughpa ialhyd ogena iono a yoilsisoneo heoldes indus ialp ocessesanda
la genumbe o pape ,pa en sandbooksha ebeenpublishedin hesubjec ,only ew
pape sha ebeende o ed o hekine icso his eac ionasshowsabo eei he in he
caseo usingnickelo palladiumca alys .Fu he mo e,chemis yandkine icso he
hyd ogena iono heunsa u a edoilsa eno mallys udiedusingsimpli ied eac ion
sys emssuchas, o example, heme hyles e o linoleicacid.Asaconsequence, he
esul so heses udiescanha dlyex ended o hein e p e a iono hebeha iou o
na u aloils, ha is,amix u eo polyunsa u a ed iglyce ides.
Thep ecedingli e a u e e iewshows ha hekine icpa ame e s o oilhyd ogena ion
a eno comple elywellunde s oodand ha he eisaneed ode elopakine icmodel
ha in ol es he a eso eac iono hedi‐andmono‐unsa u a ed iglyce idesdu ing
con inuoushyd ogena ionp ocessespeciallyunde supe c i icalcondi ions.On he
o he hand,nickelis heca alys uni e sallyemployedinindus ybu hesea chiss ill
on o aca alys ope a ingunde milde condi ionsandp oducinglowe le elso ans
isome s.In his espec ,palladiumca alys sseem obep omisinginaddi ion oi s e y
highac i i y.
3.2Objec i es.
Thischap e aims oes ablishabe e unde s andingo howope a ing a iablesa ec
sun lowe oilhyd ogena iononpalladium‐basedca alys sincombina ionwi ha
supe c i ical luidas eac ionmediuminacon inuous ecycle eac o .
Theope a ing a iableswe e a iedacco ding oas a is icalo sequen ialexpe imen al
designino de os udy hei in luenceon a eo eac ion,con e sionand inalp oduc
dis ibu ionand oes ablish heexpe imen alcondi ionswhe eapo en ialCSTR
p ocesscouldbeope a ed oob ainace ainou le iodine alue(IV)wi haminimum
ansands ea ic inalcon en incompa ison o hose epo ed o he adi ional
p ocess.
Chap e Th ee
73
Asanex ensiono hese esul s, hede e mina iono hekine iccons an sand hei
empe a u e‐dependence o hemul iple eac ionso hyd ogena ion‐isome iza ion
ne wo kin ol ing iglyce idespeciesbasedonakine ic o malismp oposedea ly o
ege ableoilhyd ogena ionswasachie edbymeanso heanalysiso heCSTR
eac ion a e.
3.3Sun lowe OilHyd ogena iononPd/CusingSCP opaneas
Reac ionSol en .
In hiscase, hehyd ogena ion eac ions udy(Ramí eze al.,2004)wascomposedo
wopa s: obuildanempi icalmodelingino de ode e mine hee ec so ope a ing
a iableson he eac ionaswellasde ining hei p ac icalope a ing anges,using
expe imen aldesignconcep s,wi h heobjec i eo ge inglow ansisome % o a
mode a eIV educ ionand inally ode e minehyd ogena ionkine icusinga eac ion
schemep oposedea lybyAlb igh (1967).
3.3.1S udyo heE ec o Ope a ingVa iablesonHyd ogena ionReac ion
bymeanso heExpe imen alDesign.
3.3.1.1C ea ing heCen alComposi eExpe imen alDesign.
All heexpe imen sca iedou ino de ode e mine heSCcon inuoussun lowe oil
hyd ogena ionkine icwe epe o medin heexpe imen alappa a usdesc ibedin
Chap e 5aswellas heanaly icalme hodsused ode e mine he eac ion a eand he
dis ibu iono hehyd ogena edp oduc s.
Ino de ocons uc heexpe imen aldesign,i mus bechosen heope a ing a iables
whichwillbemeasu edunde di e en p ocesscondi ions.F om hediscussion
p esen edabo e, heclassicalope a ing a iables ha ha ee ec on hehyd ogena ion
p ocessa e empe a u e, o alsys emp essu e,hyd ogenconcen a ion,s i ing
in ensi y,ca alys concen a ion,na u eo ca alys andoilconcen a ion.
Thephasebeha iou dependson hemix u ecomposi ion, empe a u eandp essu e.
Thus,bychoosing heapp op ia eope a ingcondi ions,asubs an iallyhomogeneous
supe c i icalphasecanbeachie ed.F om hephasebeha iou s udyde elopedin he
p e iouschap e , heinle eac ionmix u ecomposi ionwaschosenas ollows:1mol%
o sun lowe oil,2‐10mol%o H2and89‐97mol%o sol en aswellas heope a ing
p essu eand empe a u e.Wi h ega d op ocesseconomy, hesol en (ei he p opane
o DME)addi ionhas obekep oaminimum oa oidhigh ecycle olumeso his
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
74
sol en .Alsoexcesshyd ogenhas obe ecycled.Thus, hecomposi iono he eac ion
mix u eis e yimpo an o indus ialp ac ice.Highsubs a eloadingsandlow
concen a iono hyd ogena edesi able.Howe e , heconcen a iono subs a ein he
eac ionmix u eislimi edbecause he iscosi yo he eac ionmix u einc eases as as
mo esubs a eisdissol edin he eac ionsol en causing ha hesingle‐phase
condi ionscanno besecu edin he eac o (Rich e ,2000).Inaddi ion,hyd ogenisan
an i‐sol en in he eac ionmix u eand educes hesolubili yo bo hsubs a eand
p oduc as epo edVandenHa kandHä öd(2001)whoha esugges ed ha
hyd ogen/subs a emol a iosmus bea ound10o lowe .Asimila conclusionwas
eachedbyHi zle e al.(1998)who ound ha a any empe a u e, hemiscibili yo he
eac ionsys em(cyclohexane+hyd ogen+CO2)alwaysimp o edwhen he
concen a iono H2was educed.
Toachie ehomogenei y o hechosencondi ions,i is equi ed oha e8kg
p opane/kgoil ed,acco ding o hecalcula ionso Pe edae al.(2003).The aluesused
he e(12‐15kg/kg)a ewellabo e.F omanexpe imen al iewpoin unduephase
sepa a ionwe eunobse edinag eemen wi h hecalcula ionsandwi h he e na y
sys emcalcula ions.
Hi zle e al.(1998)ha e ound ha hemos d ama icchangesin hehyd ogena ed
p oduc composi ionhappenednea andjus below hec i icalp essu eo hesol en
(in hecaseo p opanePc=4.25MPaand o heDMEPc=5.37MPa).On heo he hand,
he o alsys emp essu ein hep ocessmus beabo e hec i icalp essu e(Pc)o he
mix u e(abou 6.2MPa o hemix u ewi hp opane) oensu esingle‐phase
condi ions.Themix u ec i ical alueswe ees ima edusing heChueh‐P ausni z(Reid
e al.,1987)app oxima ion.Thus,i hechosen o alp essu eis20MPa, hee ec o he
o alsys emp essu eon he eac ionisconside ednegligiblea SCope a ingcondi ions
asmen ionedp e iously.The echnical/economicallimi o hes anda dma e ialsis
somewhe ea ound30MPa.
Thec i ical empe a u e(Tc) o he eac an mix u ea hechosen eedcomposi ionis
389.15Kin hecaseo p opaneas eac ionsol en and420.15K o heDME.The
empe a u eope a ing angemus behighe han hesec i ical aluesino de o
ope a einasingle‐phasecondi ionbu no ohighasside‐p oduc scan o m(e.g.o e ‐
hyd ogena iono he eac ionp oduc s,o p oduc decomposi ion,o hyd ogena iono
o he unc ionalg oupswi hin hesubs a emolecule,o polyme isa ion eac ionso
coke o ma ion).
Chap e Th ee
75
Tocheck hep esenceo ex e nalmass‐ ans e limi a ions,measu emen so he
p oduc con e sion s. hes i ingspeed(105‐209 ad/s)we epe o med.E en hough
hemaximumagi a o speedwas391 ad/s,Au ocla eEnginee s educed his alue o
235 ad/sino de oensu e hesa eope a ionwi h lammablesubs ancesunde high
p essu eandhigh empe a u eexpe imen alcondi ions.
Thehyd ogena ion eac ionoccu edon0.1085go anindus ial2%Pd/Cca alys wi h
uni o mme aldis ibu ion,a e agepa iclesizeo 0.55mm(Degussa).Hyd ogena ion
unswe edonea e heca alys ac i i yhadbecomes able( o u he de ails,see
chap e 5).
Finally,ino de oge di e en deg eeso ha dening, hespace eloci y(LHSV),
de inedby heoil olumep ocessedpe hou byca alys olume,wasincludedasone
o hes udiedope a ing a iables.Space eloci yin adi ionaldiscon inuousoil
hyd ogena ion eac ionswi hnickelonkieselguh andac i a edca bonsuppo ed
p eciousme alca alys a ebelow1m3oil/h*m3 eac o olume.TheLHSV alues
epo ed o hecon inuous icklebedand ixedbeda ebe ween30–60m3oil/h*m3
eac o olume(Tackee al.,1997).
Basedon heconside a ionsexplainedabo e, he angeso ope a ingcondi ionsa e
showinTable3‐2as ollows:
Table3‐2:Scopeo a iableso eac ion.
VARIABLESLowle el(‐1)Highle el(+1)
Reac ion empe a u e(K)443.15473.15
Liquidhou lyspace eloci y(LHSV)(h‐1)4060
H2mol%48
Fanspeed( ad/s)105209
The o alsys emp essu e, hemola oilconcen a ionand heca alys masswe ekep
cons an a 20MPa,1mol%and0.1085g, espec i ely.
Toe alua e hee ec o hep ocess a iablesand hei in e ac ionson he
hyd ogena ion eac ion,asecondo de polynomialmodelsimila oBoxe al.(1978)
wasemployed:
2
11
kk
oiiiii ijij
ij
ii
yxx xx
ββ β β
<
==
=
++ + +∈
∑∑ ∑∑ (3.30)
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
76
Thisdesc ibes heco ela ionsbe ween hesigni ican p edic o eac ion a iables(xi)
and hep edic ed esponses(y).
Theexpe imen swe eca iedou a di e en ope a ingcondi ionsacco ding oa4‐
a iables, wo‐le els,cen alcomposi edesign(24 ac o ialdesign+8s a poin s(SP)+1
cen e poin (CP)=25expe imen s).Thecodedexpe imen aldesignma ixesa eshown
inTable3‐3andTable3‐4.
Table3‐3:Coded24 ac o ialdesignma ix.
RUNTempe a u eLHSVH2%FanSpeed
1‐1‐1‐1‐1
21‐1‐1‐1
3‐11‐1‐1
411‐1‐1
5‐1‐11‐1
61‐11‐1
7‐111‐1
8111‐1
9‐1‐1‐11
101‐1‐11
11‐11‐11
1211‐11
13‐1‐111
141‐111
15‐1111
161111
Table3‐4:Codedcen eands a poin sdesignma ix.
RUNTempe a u eLHSVH2%Fanspeed
17(CP)0000
18(SP)‐2000
19(SP)2000
20(SP)0‐200
21(SP)0200
22(SP)00‐20
23(SP)0020
24(SP)000‐2
25(SP)0002
Chap e Th ee
77
Theobse ed esponseswe e heiodine alue(p opo ional ocon e sion)and ans
C18:1.Alinedou ac i i yca alys wasemployed.Theda ap ocessingwasdoneusing
hes a is icalpackageMini ab(Applega eandMini ab,1996).
3.3.1.2Resul sandDiscussion.
A e collec ing esponseda a, heexpe imen al ac o s ha ha eala gee ec on he
eac ionwe ede e minedusing hep‐ alues(which ep esen hep obabili yo
ejec ingnon‐signi ican expe imen al a iables)o hees ima ede ec sand he ableo
coe icien s o heini ial eg ession om heexpe imen al esul s.Then, hesecond
o de polynomialmodelswe econs uc ed.Thesigni icanceo he esul sisindica ed
by hees ima eds anda dde ia ions(s)o hemodel,whichisusedasameasu eo
dispe sion.
Thecollec ed esponseda awe e i oa ullma hema icalmodelusingMini ab,which
includes he ou main ac o s(%H2,LHSV,T, anspeed),six wo‐wayin e ac ionsand
ou quad a ic‐wayin e ac ions.
Using he aluesin hep ac o (<0.05),wede e mined he ac o s ha we esigni ican
o he esponsesunde s udy(IVand anscon en ).Soi isobse ed ha hemain
e ec wasdue oT.TheLHSV‐H2%in e ac ionandT‐H2%in e ac ioncamenex and
we emo eimpo an han hee ec so LHSVo H2%alone.Thes i e speedwas he
leas impo an ac o .F om hese ac s, hepolynomialmodelwas educedand i ed
o heexpe imen alda aagain.
The inalpolynomial eg essionequa ions o heIodineValue(p opo ional o
con e sion)and ansC18:1a e espec i ely:
22 2
34.571 0.482 1.280 29.132 0.113 0.182IV T LHSV H T H LHSV H=− + + + − − (3.31)
222
18 : 1 18.521 0.074 0.696 0.003 1.858 0.027 0.018 ans C T LHSV T LHSV H LHSV H T H=− + + − − − + (3.32)
Thees ima eds anda dde ia ions(s)o each inalpolynomial eg essionmodels(s=6
o heiodine alue(IV)ands=0.73 o he ansC18:1con en )we econside ed obe
low.Thesede ia ionswe emainlydue osomeexpe imen alins abili yo he low
a es(e.g. luc ua ionsin hegas eed low)o oanaly ical a iabili y(lacko p ecision)
p oblems.
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
78
F om heexpe imen spe o med,i couldbeobse ed hananinc easeei he in he
empe a u e, heLHSVo he%H2( o hemean alueso heo he a iables)in ol es
aninc easeincon e sionandin he ansacidcon en (seeexpe imen s17‐23onTable
3‐5).Al hough he esponseo con e sionisasexpec ed, hee ec o %H2on he ans
con en isopposi e owha isobse eda lowp essu e ege ablehyd ogena ions
(Fa au oandBa holomew,2000).Thiswasp obablydue o he ollowing eason:a
hebeginningo ahyd ogena ion,i.e.while heIViss illhigh, he anscon en islow.
As heIVdec easeswi h heinc easeo H2con en a cons an empe a u eandLHSV
mean alues, he ansconcen a ioninc easesand eachesamaximum.Thismaximum
alueisabou IV=50asbeingsugges edbyMache e al.(1999).F omIV=50down o
IV=0(i.e. ullhyd ogena ion), he anscon en dec eases,due o he o ma iono mo e
andmo esa u a es.
Table3‐5:E ec so heinc easeei he in he empe a u e, heLHSVo he%H2 o hemean
alueso heo he a iableson he esponses.
RunIV answ %C18:1w %
17117.62.312.7
18120.31.19.9
1995.174.623.0
20113.12.411.8
21119.42.111.4
22121.32.28.9
23110.73.113.1
Fo o he alueso heope a ing a iables, hee ec o empe a u eisno asclea
becauseo hein e ac ionsbe ween a iables.Tha is, hee ec o one a iableon he
esponseo in e es dependson he alues akenby heo he a iables.Fo example,a
high empe a u e,aninc easeo H2%causesadec easein% ans, o anyLHSV,
whe eas heopposi ee ec isobse eda low empe a u e.
WhenLHSVisinc eased( o any%H2) hesamebeha iou isobse eddependingon
he alueo empe a u e.I he empe a u eislow,% ansinc easesandi empe a u e
ishigh, he anscon en goesdown(SeeFigs3‐2aand3‐2b).Fo sho con ac imes
(highLHSV),aninc easein empe a u edec eases he anscon en ( o %H2<6%)
whe eas o lowLHSV heopposi ee ec isobse ed,i espec i eo %H2in he eed.
Chap e Th ee
79
Figu e3‐2:Con ou mapbasedonempi icalquad a icmodel.High anspeed:a)LHSV s
%H2a 488.15K;b)LHSV s%H2a 428.15K.
Qui esu p isingly,i isobse ed ha a highspace eloci ies,aninc easein
empe a u eo H2concen a ionmakeshyd ogena ionex ensionla ge hana low
space eloci ies.ThisisseeninFigs3‐3aand3‐3b, espec i ely.Kine ically, hisisno
heexpec edbeha iou .Apossibleexplana ionis han o lowLHSVaninc easeinH2
p oducesadec easeinsolubili yo oilin he eac ionmedium,whichb ingsabou
somecondensa ionin heca alys po es, husinc easingin e nalmass ans e
esis ance.
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
80
Figu e3‐3:Con ou mapbasedonempi icalquad a icmodel.High anspeed:a)%H2 sTa
LHSV=70h‐1b)%H2 sTa LHSV=30h‐1.
Thee ec o he ecycle a ewasalsoconside edin hedesign.Aninc easeinope a ing
anspeed om52 ad/s o262 ad/sp oducesasligh inc easein a e(highe
con e sion).Thee ec o s i ingspeedon he anscon en issimila o ha on heIV.
Thephysicale ec o inc easing anspeedon anscon en isconsis en wi h hee ec
o emo ingsomeo hedi usion esis anceinane o mul iple eac ions(Smi h,1981),
whichimp o es heyieldinin e media es.Whilein hep esen eac o issmall,i s
e ec canno beo e lookedinapackedbed eac o wi hou ecycleandwi hla ge size
o ca alys ,pa icula lyi e ylow ansisome iswan edinindus ialp oduc ion.As
shows he ollowing igu e:
Chap e Th ee
81
Figu e3‐4:Con ou mapson hee ec o he eac o ecyclespeeda di e en empe a u es
a cons an highspace eloci yandla ge%H2.
F om hes udyo heope a ing a iablesonIV educ ionand anscon en and hei
in e ac ions,i ispossible ode i edi e en se so eac ioncondi ionsleading o
inc easedcon e sionwhilea hesame imelowe ing he ansC18:1isome con en .So
inp inciple,onese o possible eac ioncondi ionswouldbe oope a e he eac o a
hehigh empe a u e angeandhighH2% ange oge he wi hahighspace eloci y
(LHSV).Bycon as ,asecondcombina ionwouldbe ousealowLHSV,alowTanda
H2%less han4.The ea eo he possibili iesaswell.
Inp ac ice,a inalhyd ogena ionp oduc canbeob ained ha exhibi salow ans
C18:1a con e sionbyle ingsomeinc easein hecon en o sa u a es(in he o mo
s ea icchains)o byha ingalowdeg eeo mono‐unsa u a ed.In he o me case, he
inalp oduc couldha esui ableplas icp ope ies,bu couldbeobjec ionable oma
heal h iewpoin .In hesecondcase, henecessa yplas ici ywouldno besui able o
o he applica ions.
F om he esul so hiss udy,i ispossible ode e mine heop imumope a ing
condi ions oob aina inalhyd ogena edp oduc o immedia e oodapplica ion( o
example o ma ga ine/sho eningsp oduc ion),such ha i hasalow anscon en
(<3%)andamode a eIV educ ion( inal90<IV<110) oge he wi has ea iccon en
ela i elylow(<20%).Figs3‐aand3‐bshowdi e en al e na i eope a ingcondi ions
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
88
0,001
0,010
0,100
1,000
10,000
0,001 0,010 0,100 1,000 10,000
Expe imen al concen a ion (mol/m3)
P edic ed concen a ion (mol/m3)
C18:2
C18:1 cis
C18:1 ans
C18:0
CH2
Figu e3‐9:Pa i yplo o componen concen a ionsinCSTR s hosep edic edbykine ic
model.
Despi e he ac o heselec iono heexpe imen s o hekine ics udiesshouldco e
con e sion angesbe ween30and80%(Gonzáleze al.,1999),in hecaseo selec i e
hyd ogena iono ege ablesoils o ma ga inesp oduc ion, heexpec edcon e sionis
a ound50%.In hep esen cases udy hemaximumcon e sion eachedwasa ound
31%.
In he25 unspe o med, heaccu acyisdi e en dependingon hespecies; o
example,hyd ogenup akeis e yaccu a ely i edwhiles ea ices e islesswell
p edic ed.The ans‐con en isalsowellp edic edwi h hep esen kine icmodel(see
Fig.3‐9).I isseen ha due oali le educ ioniniodine alues(inle IV=130,exi
IV=90), hekine iccons an s o s ea ices e o ma ionmayha emo ee o .
Basedon heli e a u eal eadyci ed he ewas eason oassume ha k24andk34a e
equal.F om he esul so hesecalcula ions, hisassump ionseems obein alid.Rase
(1977)haddi icul yinadjus ing hese alues oo.Hesugges ed ha helacko i wi h
hemodel o he alueso k24andk34wouldsugges heneed o independen e idence
oes ablish he uemagni udeso hesecons an s.Themodelseemsno e ysensi i e
o hese aluesasmeasu edbyo e allpe o mancesuchasiodine alueand eac ion
ime.
Es ima ed a econs an aluescon i m ha ansisome ismo e eac i e hancismono‐
unsa u a edspecie.Themajo i yo he alueso heequilib ium a ioo hemono‐
Chap e Th ee
89
unsa u a ed a yacids(K=k32/k23)ob ained om hesecalcula ionsa einag eemen
wi h hose epo edbyAlb igh (1962)andGu (1979) o hehyd ogena iono
sun lowe oil.Theseau ho s epo edK aluesbe ween2and4.In hesameway, he
beha iou o Kwi h he eac ion empe a u eisasbeingexpec edin hecaseo an
exo he mic eac ion.
The empe a u edependenceo he eac ion a econs an swasassumed oobey he
A heniusequa ionas:
/
() ERT
i
ii
kT Ae
−
=
(3.40)
whe eAiis hep e‐exponen ial ac o ,Eiis heappa en ac i a ionene gy,Ris hegas
cons an andTis heabsolu e empe a u e.Table3‐8p esen sEi aluesob ained oma
plo o lnki e sus1/T.
Table3‐8:Kine icpa ame e s,acco ding oequa ion(3.40), o hehyd ogena iono
sun lowe oilo e Pd/Casca alys andp opaneassol en .
Reac ionEi
(J/mol)
Ai
[mol‐1/2.(m3)3/2.kg‐1.s‐1]
1235892.431.61
131472.154.25x10‐06
24265761.487.08x10+24†
34148844.393.25x10+11†
2334962.053.84
3269.721.48x10‐3
†[mol‐1.(m3)2.kg‐1.s‐1]
F om he esul sp esen edabo e,i couldbe ealized ha poly‐unsa u a edspecie(L)
ishyd ogena edsubs an ially as e han hemono‐unsa u a edspecies(Oo E)as
sugges hei appa en ac i a ionene gy alues.
Ala e discussionabou hekine icpa ame e sob ainedwillbep esen edin helas
sec iono hischap e alongwi h he esul sob ained o heo he kine iccases udy
(oilhyd ogena iono e Pd/Al2O3usingDME)andwi h hose epo edin hea ailable
li e a u e.
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
90
3.4Sun lowe OilHyd ogena iono e Pd/Al2O3usingSCDMEas
Reac ionSol en .
In hiscase,SCoilhyd ogena ionwaspe o manceoneggshellPd/Al2O3ino de o
s udy hee ec o alessadso p i eca alys ssuppo oncon e sionandp oduc
dis ibu ionincombina ionwi ha“sligh ly”be e eac ionsol en :DME.Asmallse
o highp essu eexpe imen swe eca iedou ino de obuildakine ichyd ogena ion
model.Theda a ea men ode e mine hehyd ogena ionkine icpa ame e swas
madeinasimila way o hep opanecaseusing he eac ionschemep oposedby
Alb igh (1967).
3.4.1Expe imen alConside a ions.
Basedon hep elimina yexpe iencewi hp opane, heideao pe o manceano he
expe imen aldesigns udywas ejec edbecausei would akealong imeandwouldbe
ooexpensi ebecause heDMEisno acommonsol en .On heo he hand,B akee al.
(2002)andWeidne e al.(2004)ha e epo ed ha hep incipal he modynamic
beha iou o DMEin he iglyce ideshyd ogena ionissimila o ha in hep opane
sys embu DMEisasligh lybe e sol en due oi sla ge egiono comple esys em
miscibili y.
Ase o p elimina y unsunde equalexpe imen alcondi ionsexcep he eac ion
sol en used(p opaneo DME)sugges s ha he a eo eac ionis ai lyhighe
(a ound3%)in hecaseo DMEwhichisinag eemen wi h he esul so B akee al.
(2002)andWeidne e al.(2004)men ionedabo e.
Asin he o me cases udy,all heexpe imen sca iedou ino de ode e mine heSC
con inuoussun lowe oilhyd ogena ionkine icwe epe o medin heexpe imen al
appa a usdesc ibedinChap e 5aswellas heanaly icalme hodsused ode e mine
he eac ion a eand hedis ibu iono hehyd ogena edp oduc s.Hyd ogena ion
unswe edonea e heca alys ac i i yhadbecomes able.
Thehyd ogena ion eac ionoccu edo e anindus ial0.5%Pdonaluminasuppo ed
ca alys (JohnsonMa hey).Eggshellsphe eso 2mmnominalsizewe eused o educe
in e nalmass‐ ans e limi a ions.Theamoun o ca alys was a iedbe ween0.4and1
gino de oob ainacon e siondeg eesimila o ha o hep opanecaseand o
in oduce hemix u e‐weigh ‐hou ly‐space‐ eloci y(WHSV)asexpe imen al a iable
ins eado LHSV.TheWHSVisde inedby hemasso eac an mix u ep ocessedpe
Chap e Th ee
91
hou pe g amo ca alys .Thiscanbeassumedasaspace eloci y,whichmigh a i s
sigh is ega dedas he ecip ocalo heappa en esiden ime.TheWHSV a ia ion
made a ying heamoun o ca alys ins eado hemasso eac an mix u ewasdue o
heexpansion al e,whichdidno allowse inglowsol en olume ic lows.
F om hephasebeha iou s udyde elopedin hep e iouschap e , heinle eac ion
mix u ecomposi ion o hiscasewaschosenas ollows:1mol%o sun lowe oil,4‐14
mol%o H2and85‐95mol%o DMEaswellas heope a ingp essu esand
empe a u eswhichensu esingle‐phase eac ioncondi ions.Thec i icalp essu eand
empe a u e o hechosenmola composi ionswas8MPaand420.15K espec i ely.
These alueswe ees ima edusing heChueh‐P ausni z(Reide al.,1987)
app oxima ion.The e o e, heope a ing o alp essu ewasselec edequal o20MPain
o de oelimina ei spossiblee ec on hehyd ogena edp oduc composi ionas
men ionedbyHi zle e al.(1998).
Thes i e speedwas131 ad/s o allexpe imen al unsbecausea e his h eshold
alue, hekine icbecomesindependen o agi a ion.
Theexpe imen al anges o heexpe imen al a iables, empe a u e,H2mol%and
WHSVwe eas ollows:
Tempe a u e:456.15‐513.15K
H2mol%:4‐9
WHSV:200‐600h‐1
Ca alys weigh :0.4 o1g
Theywe e a iedacco ding oasequen ialdesign,whe e heexpe imen swe echosen
eachoneo hemdependingon heob ained esul s om hep e iousone.This ypeo
designisespeciallyapp op ia e o buildingkine ics udiesbecausei educes he
numbe o expe imen s ope o mance.Asumma yo expe imen alope a ing
condi ionsca iedou isp esen edinTable3‐9.
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
92
Table3‐9:Ope a ingexpe imen alcondi ionsusedin hesun lowe oilhyd ogena iono e
Pd/Al203wi hDMEas eac ionsol en .
RUNReac ion
Tempe a u e(K)
H2
mol%
WHSV
(h‐1)
Ca alys
Weigh (g)
1483.154567.20.4
2456.154567.20.4
3483.154283.60.9
4456.154283.60.9
5483.154203.00.9
6483.158203.31
7483.159203.51
8456.154204.51
9456.157204.71
10456.159204.91
11513.154203.11
12513.157203.31
13513.159203.51
14513.154283.81
15513.157284.21
3.4.2Kine icAnalysiso CSTRDa a:Resul sandModeling.
The esul s om he i eenexpe imen al unsa ep esen edinTable3‐10.
Table3‐10:E ec o eac ioncondi ionsonsun lowe oilhyd ogena ion.Oilconcen a ion:
1mol%;P=20MPa;ca alys :0.5%Pd/Al203;sol en :DME.
RUNIV answ %C18:0w %
1116.70.47.4
2128.70.37.4
3108.72.47.9
4117.90.97.5
5104.64.79.8
6102.84.09.1
7100.23.810.9
8112.92.49.4
9111.72.39.3
10110.42.09.1
11101.56.115.2
1299.05.815.5
1394.05.019.3
14109.75.715.7
15104.75.217.8
Chap e Th ee
93
Basedon hecollec edexpe imen alda a,i couldbe ealized ha a isein empe a u e
and/o appa en ise imeinc eases he eac ion a eand,consequen ly,lowe s heIV
(seeFigu e3‐10).
85
95
105
115
125
135
0 100 200 300 400 500 600
WHSV (h-1)
ou IV
0
2
4
6
8
10
0 112233
LHSV (h-1)
ans w %
456 K
483 K
513 K
Figu e3‐10:Iodine alue(IV)and anscon en asa unc iono empe a u eandspace
eloci ya 4%H2molcon en .Solidline=IV,dashedline= anscon en .
Thee ec o H2con en isdependingon he empe a u e.A high empe a u e,an
inc easeinH2con en inc eases he eac ion a e,bu hise ec dec easeswi h
dec easing empe a u e.Thisbeha iou canbeexplainedwi h hechangingac i i yo
heca alys a di e en empe a u es:A high empe a u e heca alys ac i i yishigh,
hus,i mo ehyd ogenisadded, his esul sinhighe eac ion a e.A low empe a u e
heca alys ac i i yislowe : heca alys issa u a edwi hhyd ogenal eadya lowH2
con en sandcanno con e addi ionalhyd ogen(Mache e al.,1999andVandenHa k
e al.,2001).The e o e,aninc easeinH2con en hasalowe ec a low empe a u eas
shows heFigu e3‐11.
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
94
85
95
105
115
125
135
246810
H2 mol %
ou IV
0
2
4
6
8
10
ans w %
456 K
483 K
513 K
Figu e3‐11:Iodine alue(IV)and anscon en asa unc iono empe a u eandH2mol
con en a WHSV=200h‐1.Solidline=IV,dashedline= anscon en .
The anscon en inc eased,when he empe a u eand/o he esidence imewas
inc easedascouldbeobse edinFigu e3‐10.A highappa en esidence ime, he
anscon en dec easeswi hinc easingH2con en a any empe a u e(seeFigu e3‐11).
The endsinFig.3‐10and3‐11indica e ha he ans o ma ioncanbe u he educed,
i he empe a u e,aswellas he esidence ime,a edec eased.Since hee ec o
hyd ogenp essu ewasno signi ican a low empe a u es, hisindica es ha alow
anscon en scanpe hapse enbeob aineda lowhyd ogenp essu es.
Fo hesamedeg eeo hyd ogena ion(IV=95‐110), he anscon en ob ainedin he
expe imen al unsissimila han ha ob ainedin he o me cases udy(Pd/Cin
combina ionwi hp opane)whe eas hes ea iccon en (exp essedas%newly o med
s ea icbasedonini ials ea icin eed)issligh lylowe (<2.7)aswellas heo e all
hyd ogena ion a e.
These ac sa epossiblyde i ed om heca alys ypeemployedineachcase.In he
o me , heca alys issuppo edonac i a edca bon,whichadso bs he eac an s e y
s onglyp oducingspillo e o hespecies om heme al o hesuppo and ice‐ e sa.
On heo he hand,ac i a edca bonhasapo esizedis ibu ionconsis ingo
mic opo es(dpo e<3nm).Thiscombina ionadded o he ac ha heme alloca ionis
uni o m,lead oadec easeo helinoleicselec i i y(SI)becauseo hep esenceo po e
Chap e Th ee
95
di usional esis ancewhichinc easessa u a edcompoundsp oduc ionassugges ed
byCoenen(1976).
In hela e case, heca alys suppo wasAl2O3and heme alloca ioniseggshell ype.
Thiskindo suppo islessadso p i e hanac i a edca bonandi spo esize
dis ibu ionismainlymesopo es(3nm<dpo e<5nm).This ac alongwi h heeggshell
dis ibu ion,whichminimizespo edi usion esis ance,commonin hep ocessingo
la geo ganicmolecules,makes heemployedca alys mo eselec i e.
Aca alys wi hauni o mme alloca ionismo eac i ea highp essu es hanan
eggshellca alys asshowsFigu e3‐12.Thisis hepossibleexplana ion o heless
hyd ogena ion a eob ainedin hecaseo eggshellca alys .
Figu e3‐12E ec o hyd ogenp essu eon hehyd ogena ionac i i yo heca alys .
Thekine ics o sun lowe oilhyd ogena ionusingacomme cialPd/Al2O3ca alys and
DMEas eac ionsol en ,we ein es iga edusing hesameapp oach han ha in he
o me cases udy.
Fi s a all, he eac iono de wascheckedwi h espec oo e allhyd ogen
consump ion a ebymeanso plo inglog( a eda a)asa unc iono log(hyd ogen
pa ialp essu e).Theslopeo he eg essionlineis0.42asshowsFigu e3‐13.The
ob ained alueisclose o heexpec ed alue,0.5.
Kine icso heSun lowe OilHyd ogena ionP ocesso e Palladium‐BasedCa alys
96
y = 0.42x - 5.48
R
2
= 0.99
-6.0
-5.8
-5.6
-5.4
-5.2
-5.0
-0.4 -0.2 0.0 0.2 0.4 0.6
Ln Pp H
2
(MPa)
Ln H
2
(mol.s
-1
.kg
-1
)
483.15 K
Figu e3‐13:Linea isedplo o hyd ogenup ake a e:Ln H2 sLnpH2, o 483.15K.
Thekine icexp essionsa eassumed o he eac ionschemep oposedbyAlb igh
(1967)using hesameassump ions.Theob ained esul s o hekine icpa ame e sa e
p esen edinTable3‐11.
Table3‐11:Fi edkine icpa ame e s alues o Pd/Al2O3–DME eac ionsys em.
T(K)
Pa ame e 456.15483.15513.15
k12
[mol‐1/2.(m3)3/2.kg‐1.s‐1]
4.09x10‐6±
5.29x10‐7
4.54x10‐6±
1.77x10‐6
9.76x10‐6±
8.78x10‐7
k13
[mol‐1/2.(m3)3/2.kg‐1.s‐1]
3.32x10‐6±
8.38x10‐7
5.69x10‐6±
3.56x10‐6
2.21x10‐5±
3.89x10‐6
k24
[mol‐1.(m3)2.kg‐1.s‐1]
1.10x10‐5±
1.94x10‐6
1.85x10‐5±
2.15x10‐6
2.05x10‐5±
2.08x10‐6
k34
[mol‐1.(m3)2.kg‐1.s‐1]
2.78x10‐6±
5.12x10‐7
2.48x10‐5±
2.94x10‐6
8.99x10‐5±
4.21x10‐5
k23
[mol‐1/2.(m3)3/2.kg‐1.s‐1]
4.03x10‐6±
9.40x10‐7
6.94x10‐5±
2.40x10‐5
2.39x10‐4±
4.78x10‐5
k32
[mol‐1/2.(m3)3/2.kg‐1.s‐1]
5.69x10‐6±
1.83x10‐6
3.43x10‐4±
1.25x10‐4
8.79x10‐4±
2.37x10‐5
χ2[mol2.m‐6]8.233x10‐51.913x10‐4 2.594x10‐4
Figu e3‐14showsacompa isonbe weenexpe imen alandp edic edda a o he a y
acidcomposi ions.
Chap e Th ee
97
0.001
0.010
0.100
1.000
10.000
0.001 0.010 0.100 1.000 10.000
Expe imen al concen a ion (mol/m3)
P edic ed concen a ion (mol/m3)
C18:2
C18:1 cis
C18:1 ans
C18:0
CH2
Figu e3‐14Pa i yplo o componen concen a ionsinCSTR s hosep edic edbykine ic
model.
Ascanbeobse edin his igu e, heaccu acyda a o he anscon en isno
comple elygoodwhe eas heo he componen sa ewellp edic edwi h hekine ic
model.Theexplana ion o hesede ia ions(whicha emainlya 483.15K)couldcome
om helacko analy icalp ecision.
Asin he o me case, hemodelseemsno e ysensi i e ok11andk12.These aluesa e
no equalwhichwouldsugges ha cisand ansmono‐unsa u a edspeciesa eno
equallyhyd ogena ed o hes ea a e.Theob ainedK aluesag eewi h hoseea ly
men ioned.
Obeying heA heniuslaw,Table3‐12shows heappa en ac i a ionene giesEi
ob ained omaplo o lnki e sus1/T.
Table3‐12:Kine icpa ame e s,acco ding oequa ion(3.40), o hyd ogena iono sun lowe
oilusingPd/Al2O3asca alys andDMEassol en .
Reac ionEi
(J/mol)
Ai
[mol‐1/2.(m3)3/2.kg‐1.s‐1]
1219283.595.56x10‐4
1364069.9467.96
2419025.841.71x10‐3†
34106382.755.64x10+6†
23152444.528.97x10+11
32194615.161.09x10+17
†[mol‐1.(m3)2.kg‐1.s‐1]
105
Chap e Fou
In apa icleDi usioninPo ousCa alys Pa iclesusedin
Supe c i icalSun lowe OilHyd ogena ion.
4.1In oduc ion.
I wasassumed ha eachsi eo heen i eca alys su acewasaccessible o hesame
eac an concen a ioninsu ace eac ions.Howe e ,whe e he eac an sdi usein o
hepo eso heca alys pelle , heconcen a iona hepo emou hwillbehighe han
ha inside hepo e,andi canbeseen ha heen i eca aly icsu aceisno accessible
o hesameconcen a ion.Toaccoun o a ia ionsinconcen a ion h oughou he
pelle ,apa ame e knownas hee ec i eness ac o isin oduced.
Thepo esin hepelle a eno s aigh andcylind ical; heyconsis o ane wo ko
o uous,in e connec ingpa hso a yingc osssec ional‐a eas.I wouldno be easible
odesc ibe hedi usionwi hineachande e yoneo he o uouspa hways
indi idually;consequen ly,i shallde ineane ec i edi usioncoe icien soas o
desc ibe hea e agedi usion akingplacea anyposi ion in hepelle .I shall
conside only adial a ia ionsin heconcen a ion; he adial luxWi willbebasedon
he o ala ea( oidsandsolid)no mal odi usiondi ec ion a he han oida eaalone.
Thesebasis o Wi a emadepossiblebyp ope de ini iono hee ec i edi usi i yDe.
Thee ec i edi usi i yis akenin oaccoun since:
1 No allo hea eano mal o hedi ec iono he luxisa ailable(i.e., oid) o
hemolecules odi use.
2 Thepa hsa e o uous.
3 Thepo esa eo a yingc oss‐sec ionala ea.
Anequa ion ha ela esDe oei he hebulko heKnudsendi usi i yis
p
e
D
D
ε
τ
=.(4.1)
whe eDis heglobalmolecula di usi i y,εpis hepelle po osi yandτis he
o uosi y ac o .τisde inedas he a ioo hedis ance h oughwhich hespeciesha e
odi usein hepo ousmedia o helinea dis ancebe ween he wopoin s.Equa ion
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
106
4.1is alidwhen hedi usioninpo esoccu sbymolecula di usionandwhen he
diame e o hedi usingmoleculeissu icien lysmallcompa ed o hea e agepo e
diame e so heKnudsendi usionisnegligible.
In heabsenceo expe imen alda a,i isnecessa y oes ima eDe om hephysical
p ope ieso heca alys .In hiscase he i s s epis oe alua e hedi usi i y o a
singlecylind icalpo e.Thenageome icmodelo hepo esys emisused ocon e D
oDe o hepo ouspelle .Amodelisnecessa ybecause hegeome yo he oid
spacesisqui ecomplex.Theop imummodelisa ealis icp esen a iono hegeome y
o he oids(wi h ac ablema hema ics) ha canbedesc ibedin e mso easily
measu ablephysicalp ope ieso heca alys pelle .Thesep ope iesa e hesu ace
a eaandpo e olumepe g am, hedensi yo hesolidphase,and hedis ibu iono
oid olumeacco ding o hepo esize.
The andom‐po emodelwaso iginallyde eloped o pelle scon ainingabidispe se
po esys em.I issupposed ha hepelle consis so anassemblyo smallpa icles.
When hepa icles hemsel escon ainpo es(mic opo es), he eexis sbo hamac o
andamic o oid‐ olumedis ibu ion.The oidsa eno imaginedascapilla ies,bu
mo easanassemblyo sho oid egionssu oundingandbe weenindi idual
pa icles,asindica edinFigu e4‐1.
Figu e4‐1:Random‐po emodel.
Thena u eo hein e connec iono mac oandmic o oids egionsis heessenceo he
model.T anspo in hepelle isassumed ooccu byacombina iono di usion
h ough hemac o egions(o oids ac ionεM), hemic o egions(o oid ac ionεμ),
andase ieso con ibu ionsin ol ingbo h egions.I issupposed ha bo hmic oand
mac o egionscanbe ep esen edass aigh ,sho cylind icalpo eso a e age adiiāM
Chap e Fou
107
andāμ.Themagni udeo indi idualcon ibu ionsisdependen on hei e ec i ec oss‐
sec ionala eas(pe pendicula o hedi ec iono di usion):Thede ailso he
de elopmen a egi enelsewhe e(WakaoandSmi h,1962and1964)bu ingene al
hesea easa ee alua ed om hep obabili yo po ein e connec ions.The esul an
exp ession o Demaybew i enas ollows:
2
2(1 3 )
1
M
eMM
M
DD D
µ
µ
εε
εε
+
=+
−(4.2)
whe eM
DandD
µ
o mac oandmic o egionsin e mso hebulkdi usi i yDABand
Knudsendi usi i yDKa e:
11 1
()
MAB KM
DD D
=+ (4.3)
11 1
()
AB K
DD D
µ
µ
=+ (4.4)
No e ha nei he he o uosi y ac o no o he i ingpa ame e isin ol edin his
model.Theac ualpa hleng hisequal o hedis ancecoo dina ein hedi ec iono
di usion.Toapplyequa ion4.2 equi es oid ac ionsandmeanpo e adii o bo h
mac oandmic o egions.Themeanpo e adiicanbecalcula ed o hemic o egion
ompo osime yda a.
The andom‐po emodelcanalsobeapplied omonodispe sesys ems.Fo apelle
con ainingonlymac opo es,εμ=0.Consequen ly,equa ion4.2becomes:
2
eMM
DD
ε
=(4.5)
Simila ly, o ama e ialassilicagel,whe eεM=0, hee ec i edi usi i yis:
2
e
DD
µ
µ
ε
=(4.6)
Compa isono heselas woequa ionswi hequa ion4.1indica es ha τ=1/ε.The
signi icanceo hismodelis ha hee ec i edi usi i yisp opo ional o hesqua eo
hepo osi y.F omexpe imen alda a o a iousca alys s,i hasbeen ound ha τ
a ies omless hanuni y omo e han6.
To uosi y ac o sless hanuni ycanoccu when hesu acedi usionissigni ican .
Sa e ield(1970)hassumma izedda a o ca alys s om heli e a u eand
ecommended heuseo τ=4whensu acedi usionisinsigni ican .Onlya ewau ho s
ha emeasu edτdi ec lyinhigh‐p essu e,high‐densi ynon‐ eac i esys ems(Laiand
Tan,1993;S übe e al.,1997andAba oudie al.,1999).On heo he hand, hishasbeen
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
108
measu ed o manyca alys sunde low‐p essu eandmedium‐p essu econdi ionsas
summa izedinTable4‐1.
Table4‐1:To uosi y ac o s o di usioninca alys sa 6.5MPa(Bu ,1999).
Ca alys In e nal
Po osi y
To uosi y
Fac o τ
Ha shawMeOHsyn hesisca alys (p e‐ educed)0.496.9
Haldo ‐TopsoeMeOHsyn hesisca alys (p e‐
educed)
0.433.3
BASFMeOHsyn hesisca alys (p e‐ educed)0.507.5
Gi dle G‐52ca .,33%Nion e ac o yoxide
suppo
0.444.5
Gi dle G‐58ca alys Pd/Al2O3(0.6MPa)0.392.8
The oleo Knudsendi usionDKindensemediaseems obenegligible(LaiandTan,
1993).Howe e ,sincemoleculesa eclose oeacho he inadensemedium(liquido
comp essedgas),di usi i iesa edi icul op edic (Smi h,1981).Di ec measu emen s
o De aluesindensegasha ebeenob ainedinsi ua ionswhe e hein a‐pa icle a e
wascon olling.Insuchcases, he o uosi y ac o sob aineda e e ysmallindeed,as
epo edbysomeo he aluesinTable4‐1.Kna andSchlünde (1987)we e he i s o
no eanabno mallylow a ioo D/De(~1.5) ha wasalso a iablewi h empe a u e.
To uosi y ac o sless hanuni yha ebeeno enbeen epo ed o h ee‐phase
ca aly ic eac o swhe ea eac an gasdi usesinaliquid‐(o dense)medium.Many
examplesa ea ailable.Adiscussiono hepossiblecauseso heabno mal o uosi y
ac o sisgi enbyS übe e al.(1997).Thesea e ela ed o hepossibleexis enceo co‐
ope a i esu acedi usionwi hbulkpo e luiddi usion.
Whenso p iono hedi usingspeciesoccu s, woaddi ionalcomplica ionsmaya ise.
Fi s , heso bedphasecanha eanaccumula iono solu esu icien lyla ge ha i mus
beincludedin hemassbalanceequa ions.Second, heso bedphasecouldbemobile,
whichwouldbeadded o hedi usion lux.The o me casehasbeenex ensi ely
conside edinase ieso pape sbyWeisze al.(1967,1968,and1973).Themass ans e
equa ionbecomes:
Al
AA
pp e
C
CC
D
zz
ερ
∂
∂∂
∂
+=
∂∂∂∂
(4.7)
Chap e Fou
109
whe eCAl=CAl(CA) h ough headso p ionp ocess.I ins an aneousadso p ion
equilib iumisassumed, he unc ional o mis ound om heiso he m,and( o
cons an De)
2
2
.
AA
a
CC
D
z
∂∂
⎛⎞
=⎜⎟
∂∂
⎝⎠
(4.8)
whe eDaisamodi ieddi usi i y ha doesno ha e hesame alueas hes eady‐s a e
alueDee en heusualdi usion esul scanbeusedwi h hisequa ion.ThisDais
de inedas:
e
a
Al
pp
A
D
DdC
dC
ερ
⎛⎞
⎜⎟
⎜⎟
=⎜⎟
+
⎜⎟
⎝⎠
(4.9)
Thesecondsi ua iono “su acedi usion”islesswellunde s ood.I isusually
ep esen edbyaFickian‐ ype luxexp ession,using headso bedconcen a ionas he
d i ing o ce:
Al
ssp
dC
NDdz
ρ
=− (4.10)
I ins an aneousadso p ionequilib iumisagainassumed, he o al luxis:
()
Al A
ALsp
A
dC dC
NDD
dC dz
ρ
⎛⎞
=− + ⎜⎟
⎝⎠
(4.11)
whe eDLis hee ec i epo e‐ olumedi usi i yandDSis hee ec i esu ace
di usi i y.
Thus,excep o asimplelinea iso he m,CAl=(C KA).CA, hedi usi i yisconcen a ion
dependen .Themassbalancenowbecomes:
2
,
1()
()
Al
A A
Lsp
Al A
pp
A
dC
CC
DD
dC
zdCz
dC
ρ
ερ
⎛⎞
∂∂∂
=+
⎜⎟
∂∂ ∂
⎝⎠
+
(4.12)
which, o alinea iso he m, educes o:
2
2
()()
Lsp A
AA
pp A
DDCK
CC
CKz
ρ
ερ
+
∂∂
=
∂+ ∂
(4.13)
F om hisequa ion, heo e alle ec i edi usi i yDecan henbe iewedasa esul o
combina iono woe ec s:(a)apo e olumedi usionwi hane ec i ecoe icien
de inedbyEqua ion4.1,and(b)asu acedi usioncon ibu ion.When headso p ion
ollowsalinea iso he m, hee ec i edi usi i ycanbeexp essedas:
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
110
ʹ
As
pp
e
KD
D
D
ρ
ε
ττ
=+ (4.14)
whe eKAis headso p ionequilib iumcons an on hesolid om hehigh‐p essu e
luidandDsis hecommonsu acedi usioncoe icien .Since hesequan i iesa e
seldoma ailable,ana e ageo appa en o uosi y ac o isemployed(see he alues
inTable4‐2)indica ing ha achangein empe a u emayla gelya ec KA,whichmay
lowe hee ec i edi usi i ywi hinc easing empe a u e, husshowinga e e se‐
empe a u ee ec .
Table4‐2:To uosi y ac o s o high‐p essu eex ac iono po oussolids(S übe e al.,1997).
Au ho sOpe a ingCondi ionsSolidMa ixTo uosi yFac o τ
Kna and
Schlünde (1987)
308.15‐328.15K
12‐22.6MPa
B onze,εp=0.3
Po esize8‐
20x10‐6m
τindep.o dpandP
τ=0.4 o0.54
Recasense al.
(1989)
Deso p ionE Ac
300.15‐338.15K,P<13
MPa†
Regene a ion
o ac i a ed
ca bon
Linea d i ing o ce
modelτ=4
Mad ase al.
(1994)
Naph haleneadso p ion,
298.15‐318.15K
8‐31MPa
Mic o‐and
mac opo ous
alumina
τcons .w/PandT
τ=3.29(a )
LaiandTan
(1993)Tolueneadso p ion
Mic o‐and
mac opo ous
ac i a ed
ca bonεp=0.45
τdependson
p essu e
τ~0.2 o0.6
S übe e al.
(1997)DiCl‐benzeneex ac ion
B onze,
mac opo es
εp=0.20 o0.25
po e
size~15x10‐6m
τcons .w/Pbu
a iesw/T
τ~0.22 o0.62
Somediscussionso he heo e icalbaseswe ep esen edbyYaandSladeke al.(1974)
o gasesandbyDed ickandBeckman(1967)andKo iyamaandSmi h(1974) o
liquids.Valueso Dsha ebeencollec edbySchneide andSmi h(1968)andSladecke
al.(1974).Fo hyd oca bongasesin heusualca alys subs a ema e ials, aluesin he
ange10‐9–10‐7m2/sa eobse ed.Thecon ibu ion o hemass luxismo eimpo an
o mic opo oussolids,andi canbeapp eciableunde somecondi ions,especiallyin
liquids.
Ano he phenomenonobse edis he es ic eddi usion.Thisoccu swhen he
dimensionso hesolu emoleculeand hepo ea ecompa able.Anumbe o
Chap e Fou
111
in es iga o s(Sa e ieldandKa ze ,1971;Sa e ieldandCheng,1972;Moo eand
Ka ze ,1972;Sa e ielde al.,1973,e c.)ha eshown ha such es ic eddi usion
occu sinsilica‐aluminaandzeoli eca alys wi hpo ediame e so less han5nm.
Sa e ielde al.(1973)ob ainedexpe imen alda aondi usioninsilica‐aluminaca alys
wi ha e y inepo ediame e o heo de o 3.2 o anumbe o solu es,such ha he
a ioo hec i icalmoleculediame e o hesolu e o hepo ediame e a ied om
0.088 o0.506.Theexpe imen alda awe eco ela edby he ollowingequa ion:
2
10
ds
d
ee
D
D
ε
τ
−
=(4.15)
whe edsis hesolu ec i icaldiame e de inedas hediame e o hesmalles cylinde
h oughwhich hesolu emoleculecanpasswi hou dis o ionanddeis hepo e
diame e .The a ioo ds odeisknownas hehinde eddi usion ac o (λ).Sa e ielde
al.(1973)conside ed ha his ac o isin he ange0.1‐0.5.
In o ma ion om heopenli e a u eon hepossible oleo in apa icledi usion
limi a ioninoilhyd ogena ioninslu y eac o sis e ylimi ed(Veldsinke al.,1997).
Fo lowp essu ehyd ogena iono co onseedoil,De,H2isapp oxima ely70 imesas
la geasDe,T iglyce idesinco onseedoil(Be ne al.,1975).In apa icledi usionlimi a ion
o iglyce ideshas,amongo he s,ap onouncede ec onlinolea eselec i i y(SI),as
canbeseen om hedec easeo SIwi hinc easingpa iclediame e (Co do aand
Ha io ,1975).
Coenen(1986)summa ized heda aondi usionlimi a ionand epo ed o ana ow
po eca alys (meanpo ediame e <dp>~4nm)a50%dec easesinac i i y ela i e oa
medium(<dp>~6nm)andwidepo e(<dp>~8nm)ca alys .Colene al.(1988)obse ed
in apa icledi usionin iolea ehyd ogena ion omwhich heycalcula ed
in apa icle iglyce idesdi usioncoe icien De,T iglyce ides=2x10‐11m2/s(widepo e
ca alys )and4x10‐12m2/s(mediumpo eca alys )a 373.15Kandanabsenceo
hyd ogenlimi a ion.
Fo me hyles e hyd ogena iono e Pd/Cca alys ,Tsu oe al.(1978)could e i y he
obse edshun eac ionsbyinco po a ingin apa iclehyd ogendi usionlimi a ion,
houghno e yaccu a elybecauseo heinsensi i i yo hecu es o he alueo
De,H2=3.6x10‐9m2/sa 443.15K.Anes ima ed alueo De,H2=4x10‐9m2/sa 443.15Kwas
ob ained om heexpe imen alda abyAnde ssone al.andGanguliandVandenBe g
(1978),whichisinag eemen wi h heda ao Tsu oe al.(1978).
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
112
Jonke e al.(1998)in es iga ed hein apa icledi usionlimi a ionin he
hyd ogena ionandisome iza iono a yacidme hyles e s(FAMEs)andsoybean
edibleoil(TAG)inpo ousnickelca alys unde eac i eandine condi ions.They
ound ha FAMEhyd ogena ion eac iona 443.15Kappea s obecon olledby
in apa icledi usiono hyd ogen(De,H2=1.6x10‐10m2/s).In hecaseo iglyce ides
hyd ogena ion, he iglyce idesappea obedi usionlimi ed(De,T iglice ydes=3.3x10‐12
m2/s) a he hanH2,whichag ees heli e a u e.Veldsink(2001)p oposes hee ec i e
iglyce idecoe icien equal o heliquid‐phase iglyce idedi usioncoe icien
di idedby10.
I issu p ising ha hesca ci yo heexpe imen alda ainligh o hesubs an ial
e ec sin apa icledi usionlimi a ionmayha eon heselec i i yo he
hyd ogena ion eac ion.In hecaseo SCFsys ems, hesi ua ionisno di e en : he eis
ag ea lacko di usionda aa ailable.Theknowledgeand heabili y op edic
anspo p ope iesinSCFsand heabili y op edic hema eo conside able
impo ancein hedesignande iciencyo hep ocessope a ion.Due o hehigh
p essu ein ol ed, hesesys emsa ehighlynon‐idealanda eno eadilydesc ibedby
p edic i ema hema icalmodels.In henume ous e iewso SCFs,speci icmen ionis
madeon helacko expe imen aldi usionda a.Asaconsequence, ew heo e icaland
empi icalmodelsexis op edic di usioncoe icien s.
Lionge al.(1991),de elopedasimpleexpe imen alme hod ha hasbeenused o
de e minedi usioncoe icien sinse e alSCFsys emsmainlyinSCCO2.Di usion
and he modynamicmeasu emen sbySFCa e e iewedbyRo h(1991)aswellas
Suá eze al.(1992).VandenHa k(2000)madea oughes ima eo hee ec i eFAME
di usi i yinSCp opanebasedonmeasu eddi usi i iesinSCCO2(Lionge al.,1992)
in heo de o 10‐9m2/sa 553.15Kand15MPa.Fo hyd ogeninSCp opane,
di usi i ywasconside edin he angeo 10‐7m2/s om hees ima ionp oposedby
Sa e ield(1970)a lowp essu e.
Asmen ionedabo e, he ea ecu en ly e y ewse so da ao di usi i yin
supe c i icalhyd ogena ionsys ems.The e o e, heaimo hischap e was os udy he
in apa icledi usi i yo iglyce idesandhyd ogenunde SChyd ogena ion eac ion
condi ionsino de ode e mine hee ec i edi usioncoe icien sin hepo ous
ca alys pa icle.Theobjec i eis oha eaninsigh abou hemass anspo
mechanismsinSC luids.
Chap e Fou
113
4.2Objec i esandS a egy.
Theobjec i eis os udy hein apa icledi usioncoe icien so iglyce idesand
hyd ogeninSCp opaneunde hyd ogena ion eac ioncondi ionson2%Pd/Cca alys .
The uein insichyd ogena ionkine ics omse e alexpe imen sin heabsenceo
di usionlimi a ionwasde e mined omsmallpa iclediame e s.Thedi usion
coe icien swe ede e mined om hebes i so hes eady‐s a edi usionand
chemical eac ioninpo ousca alys pa iclemodelunde iso he malcondi ions,
applied o hep e iouslya ailablekine iccons an s oexpe imen sca iedou unde
di usionlimi edcondi ions.The a eequa ionsa eused oin es iga e hee ec so
in apa iclehyd ogenand iglyce idesdi usionon hehyd ogena ion a e.Finally,
he a ioo molecula di usi i y,es ima edbymeanso co ela ions, oe ec i e
di usi i ywe ede e minedunde se e alope a ingcondi ions o iglyce idesaswell
ashyd ogenino de oes ablishwhich ypeo di usi i yp edomina eswi hin he
po ousca alys pa icle.
4.3De ec iono heIn e nalMassT anspo Resis ance.
A heendo chap e 3, hepossibili y ha mass anspo con ols he eac ion a ewas
pu o wa d.Mass anspo esis ancemigh esul inconcen a iong adien swi hin
hepo ousca alys (in e nalmass‐ ans e limi a ion).Theseg adien s educe he
eac an concen a ionsa heca alys su ace,which esul sinlowe eac ion a es
(No e:g adien so e gas‐liquidin e acesdono exis becauseo hesingle‐phase
eac ionmix u e).
To es whe he in e nalmass anspo hasin luenceon he eac ion a e, heca alys
diame e waschangedinp elimina y uns,seeTable4‐3.
Table4‐3:E ec o pa iclediame e on hecon e siona cons an appa en esidence ime
(4.2s).Expe imen alcondi ions:0.25go 2%Pd/Ca 20MPa, eedcomposi ion
(Oil:H2::P opane):1:4:95mol%.
RunReac ion
Tempe a u e(K)
Pa iclesize
(mm)Con e sion%GlobalH2Reac ionRa e
(mols‐1kgca ‐1x104)
1456.150.9230.671.23
2456.150.4736.862.16
3484.150.9236.542.26
4484.150.4743.643.48
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
120
Figu e4‐2:In apa icleconcen a ionp o ileso hyd ogenandoilcomponen sin2%Pd/Ca
484.15K,20MPa, eedcomposi ion(Oil:H2::P opane):1:4:95mol%.c)dp=0.47mm.
Figu e4‐3:In apa icleconcen a ionp o ilesinoilhyd ogena ioninSCp opanea 457.15
K, eedcomposi ion(Oil:H2::P opane):1:4:95mol%anddp=2mm.a)P=20MPa
c)
a)
Chap e Fou
121
Figu e4‐3:In apa icleconcen a ionp o ilesinoilhyd ogena ioninSCp opanea 457.15
K, eedcomposi ion(Oil:H2::P opane):1:4:95mol%anddp=2mm.b)P=27.5MPa.
Figu e4‐4:In apa icleconcen a ionp o ilesinoilhyd ogena ioninSCp opanea 484.15
K,P=27.51MPa.Feedcomposi ion(Oil:H2::P opane):1:4:95mol%,dp=2mm.
Fo his eason, hemodelseems obeinsensi i ea smallpa iclediame e sas
expec edbecause hein apa icledi usional esis anceisconside ednegligible.The
o ala e ageabsolu ede ia ion(AAD%)isde inedby:
exp
,
,,
2
exp
1
,,
()
100
%,,,,
.
p ed
Nqi
qi qi
i
qqi qi
DD
A
AD whe e i L O E S H
NN D
=
−
==
∑(4.25)
b)
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
122
whe eq
Nis henumbe o hyd ogena ion unswi h,qi
Ncomponen s,exp
,qi
Dand,
p ed
qi
Da e
heop imizedandp edic ed eac ion a esqua edde ia ion o eachcomponen
espec i ely.
Fo la gepa iclediame e s hemodelsensi i i ywasla ge wi h espec o he
di usi i ies alues.The a ia iono ±10 imes heop imizedH2e ec i edi usi i y
alue(2x10‐7m2/s),gene a eda a ia iononp edic edH2 a eso eac ionbe ween8
and43%incompa isonwi h heexpe imen al aluesasshowninFigu e4‐5.
0.00001
0.00010
0.00100
0.1 1 10
Slab Thickness (mm)
(m ol H
2
s
-1
kg
ca -1
)
Expe imen al
2E-6 m2/s
1.1E-6 m2/s
2E-7 m2/s
1.1E-7 m2/s
2E-8 m2/s
1.1E-8 m2/s
Ex apola ed
Figu e4‐5Sensi i i yo hep oposedmodelwi hH2e ec i edi usi i y aluesa 484.15K,
20MPa.Feedcomposi ion(Oil:H2::P opane)o 1:4:95mol%.
Thesensi i i yo hemodel oall i edpa ame e s(in insickine iccons an sand
e ec i edi usi i iesinc eased10 imes) o bo hpa iclediame e sisp esen edin
Table4‐5.Ascanbeobse ed,a hesmalles pa iclediame e , helessAAD% alues
a eob ainedwi hachangeo e ec i edi usi i ies a he hanwi h hekine ic
pa ame e s.Thesi ua ionisopposi e o hela ges pa iclediame e .
Chap e Fou
123
Table4‐5Modelsensi i i ywi h i edpa ame e sa 484.15K,20MPaand eedcomposi ion
(Oil:H2::P opane)o 1:4:95mol%.
AAD%
Pa ame e sOp imizedTes edL=2mmL=0.1mm
k12
[mol‐1/2.(m3)3/2.kg‐1.s‐1]1.5625x10‐41.5625x10‐31.105.86
k13
[mol‐1/2.(m3)3/2.kg‐1.s‐1]0.001.5625x10‐70.020.01
k24
[mol‐1.(m3)2.kg‐1.s‐1]1.8225x10‐41.8225x10‐33.7114.50
k34
[mol‐1.(m3)2.kg‐1.s‐1]3.1608x10‐53.1608x10‐43.923.23
k23
[mol‐1/2.(m3)3/2.kg‐1.s‐1]6.6595x10‐46.6595x10‐32.8787.48
k32
[mol‐1/2.(m3)3/2.kg‐1.s‐1]1.9279x10‐31.9279x10‐24.4271.60
De, iglyce ides
(m2.s‐1)9.8000x10‐89.8000x10‐7 69.990.006
De,H2
(m2.s‐1)2.0000x10‐72.0000x10‐6 70.220.003
Figu e4‐6shows hein e nale ec i eness ac o ound o se e alpa iclediame e s.
0.1
1.0
0.1 1 10
Slab Thickness (mm)
E ec i eness ac o η
Ex a
p
ola e
d
Figu e4‐6:E ec i eness ac o wi h espec ohyd ogen o se e alslabca alys pa icles
hickness.
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
124
F omFigu e4‐6,i canbeobse ed ha as hepa iclediame e becomes e ysmall(0.1
mm), hee ec i eness ac o app oaches1due o he ac ha he eac ionissu ace‐
eac ionlimi ed.On heo he hand,when hepa iclediame e inc eases, hein e nal
e ec i eness ac o ηbecomes e ylow(i.e.,<<1),so heca alys isno ullyu ilized.
Table4‐6p esen s hein insickine icpa ame e s o hesupe c i icalsun lowe
hyd ogena ionde e mined om hesolu iono hecombineddi usion‐ eac ionmodel
o hesmalles pa iclediame e .
Table4‐6:In insickine icpa ame e s o heSCsun lowe oilhyd ogena iononPd/C.
Kine icCons an s
T(K)k12*k13*k24†k34†k23*k32*
457.151.3076x10‐
40.003.2001x10‐
6
3.2854x10‐
6
3.9129x10‐
4
1.4564x10‐
3
484.151.5625x10‐
40.001.8225x10‐
4
3.1608x10‐
5
6.6595x10‐
4
1.9279x10‐
3
*[mol‐1/2.(m3)3/2.kg‐1.s‐1]†[mol‐1.(m3)2.kg‐1.s‐1]
Theminimizedχ2‐ a ge unc ion(Spiegel,1987)isde inedbyEqua ion4.26de inedas
hesqua ede ia ionbe weenexpe imen alandmodel a eo eac ion o Nq,d
expe imen alpoin so heNqhyd ogena ion unswi hNq,icomponen s:
2
exp
,,
,, ,,
2
2
exp 2
111
,, ,,
()
11 ,,,,
()
mdl
NNN
qqiqd
qid qid
qid
qqiqd qid
iLOESH
NNN
χ
===
−
==
∑∑∑ (4.26)
He e,exp
,
,qid
and
,
,
mdl
qid
a e heexpe imen allyobse edand hecalcula edmodel a eo
eac ion alues o heq hexpe imen and hei hcomponen andd hda apoin ,
espec i ely.
So heweigh ing ac o sa eal eady akenin oaccoun as hein e seo heexpec ed
alueso i.O he objec i e unc ions,basedonp obabili ylawscanbeused(F omen
andBischo ,1990).Thekine icpa ame e sa eob ainedby healgo i hmo Le enbe g‐
Ma qua d using heχ
2‐ es .The alueso ki,ja ein he angeo 10‐3‐10‐6, hus e y
widelyapa (see hes anda dde ia ioninChap e 3).
In healgo i hmo Le enbe g‐Ma qua d , he ollowingcons ainsuseda e hoseo
Table4‐7.
Chap e Fou
125
Table4‐7:Cons ainso Le enbe g‐Ma qua d algo i hm.
Pa ame e sCLCOCECSCH2
Cons ain<CL0>1x10‐5>1x10‐5>CS0<CH0
Theob ainedkine iccons an swe eusedin hes eady‐s a edi usionandchemical
eac ionmodelino de oob ain hee ec i edi usi i ieso oilandH2 espec i ely.
Table4‐8p esen s hees ima ed aluesunde di e en eac ingcondi ions.
Table4‐8:Fi ede ec i edi usioncoe icien s o hyd ogena ionspecieson2%Pd/C
ca alys (dp ange=0.47‐2mm).
T(K)P(MPa)Oilop .De
(m2.s‐1x108)
H2op .De
(m2.s‐1x107)
457.15202.940.64
457.1527.51.720.44
484.15209.802.00
484.1527.56.251.30
Thee ec i edi usi i ies esul scon i m ha hyd ogendi usemuchmo e eadily(10‐
100 imes) han he iglyce idesdue oi slowe molecula size.
I isalsoseen ha heinc easein empe a u eo hedec easeo sys emp essu eleads
oaninc easein hee ec i edi usioncoe icien sbu hee ec o empe a u eon
hemseems obeg ea e han hee ec o hep essu e.Theinc emen ine ec i e
di usioncoe icien swi h empe a u edoes ollows he endsugges edbySa e ield
(1970)whoconside ed ha i isp opo ional oTmwi hmbe ween1.5and2.Inou
case heexponen misa ound21whe eas heinc emen o e ec i edi usi i ieswi h
dec easingp essu eisdi ec lyp opo ional oP.The endsugges s ha he
p onounced empe a u edependencemaybedue o hes onge ec o empe a u eon
headso p ionequilib iumcons an s,aswewillseela e on.Thein luenceo sys em
p essu eon hee ec i edi usi i ieswaslesssigni ican a highe p essu esin he
supe c i ical egionaway om hemix u ec i icalpoin s(SeeChap e 2)inag eemen
wi h he esul s epo edbySuá eze al.(1993)andA unaja esane al.(2003).I isclea ,
ha hee ec i edi usi i ycoe icien s o iglyce idesandhyd ogenin heliquid‐
phase adi ionalhyd ogena ion eac iona emuchlowe han hosein hesupe c i ical‐
phase.
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
126
Theob ainede ec i e iglyce idesdi usi i ies aluesag eewi h hoseexpec ed o
mix u eso asupe c i icalgasandalow ola ilecomponen (10‐8m2/s)assugges edby
B unne (1994).Theya eabou oneo de o magni udehighe han ha o liquidsand
abou woo de so magni udelowe han ha o gases.In hecaseo hyd ogen
dissol edinaSCp opane,i isexpec ed ha hee ec i edi usi i ycanbeoneo de
o magni udehighe han ha inliquids(e ec i edi usi i yisa ound10‐8m2/s)
becausee en houghagasphaseisp esen , hewe ingo heca alys pa iclesby he
supe c i ical luidmeans ha hepo eswillbeessen ially illedwi h hesupe c i ical
luid,whichhasaliquid‐likedensi y.The e o edi usi ep ope iesshould esemble
hoseinliquid‐ illedpo es.
F om heconcen a ionp o ilesin heen i eca alys , heo e all eac ion a escanbe
calcula ed.Then heo e alllinolea eselec i i y(SI)o heca alys isde inedhe eas he
a ioo hene a eo o ma iono cis‐monounsa u a edcompound o hene a eo
o ma iono sa u a edspecies:
,
2
() .
O
I e iglyce ides
S
L
x
dC
dx
Linolea e Selec i i y S D dC
dx
=
⎛⎞
−⎜⎟
⎝⎠
=⎛⎞
−⎜⎟
⎝⎠
(4.27)
TheSIwasde e mined o 484.15K,20MPaandamola eedcomposi ion
(Oil:H2::P opane)o 1:4:95 o bo h, hesmalles and hela ges diame e pa icle.These
alueswe ecompa ed o hose om heclassicalde ini iono selec i i ybasedon he
kine iccons an s.Following hekine icschemeo hyd ogena ion eac ionsp oposedby
Alb igh (1967), helinolea eselec i i ywasde inedas:
12 32
24 34
I
kk
Skk
+
=+(4.28)
whichisob iously alidonlyin hechemicalkine ic egime.
A hesame ime, heSpeci icIsome iza ionde inedas he a ioo he a eo o ma iono
ans‐monounsa u a edcompound o hene a eo up akehyd ogen(seeequa ion
4.29)wasde e minedandcompa edwi h he alues om hede ini ionsugges edby
Coenen(1986)as he a ioo hepe cen ageinc easein ans‐isome con en and he
dec easeiniodine alue(IV).
Chap e Fou
127
,
,2
2
2
() .
E
e iglyce ides
i
H
eH
L
x
dC
Ddx
Speci ic Isome iza ion S dC
D
dx
=
⎛⎞
−⎜⎟
⎝⎠
=⎛⎞
−⎜⎟
⎝⎠
(4.29)
Table4‐9p esen s heob ained alues o SIand ansselec i i y.
Table4‐9:Es ima edselec i i ies o SCsun lowe oilhyd ogena ionon2%Pd/Ca 487.15K,
200MPaanda eedcomposi ion(Oil:H2::P opane)o 1:4:95mol%.
Linolea eSelec i i y(SI)Speci icIsome iza ion(Si)
Pa iclesize
(mm)Eq.4.27
Classical
kine ic
de ini ion*
Eq.4.29Coenen
de ini ion
0.17.827.550.050.04
22.117.550.080.02
*Alb igh (1967)
Ascanbeobse edin hecaseo hesmalles pa iclediame e , heSI alueob ained
om hekine iccons an sag eeswellwi h ha omEq.4.27because hesu ace
eac ionis a elimi ing.When hepa iclediame e isla ge, hedi usionusuallylimi s
heo e all a eo eac ionand o his eason, heSI aluesdono ag ee.
Theselec i i y esul sa einconco dancewi h hose epo edbyTsu oe al.(1978),
Coenen(1986),Wes e e pe al.(1987),Colene al.(1988)andVeldsinke al.(1997),who
ha e ound ha in hehyd ogena iono edibleoilsonpo ousca alys ,in apa icle
mass‐ ans e limi a ionsno only educe heca alys e ec i i iesbu alsomaychange
hep oduc selec i i ies.
Ha ingmeasu ed hekine icpa ame e sand hedi usi ep ope ieswi hin he
ca alys pa icle,weexamined hepossiblemass ans e mechanism.Webased he
analysison heabno mal o uosi y ac o (o De/D)obse edinSCFsol en .
Ino de ode e mine he a ioDe/D,whichis ela edwi h he o uosi y ac o (τ)by
equa ion4.1, hemolecula di usi i ies o oilandH2inSCp opanewe ees ima ed.In
hecaseo iglyce ides, heCa chpole‐King(1994)and heSun‐Chen(1987)
co ela ionswe eemployedinnea c i ical luids(Fo mo ede ailsseeAppendixG).
Table4‐10shows hees ima edmolecula di usi i ycoe icien s o C3H8‐T iglyce ides
andC3H8‐H2pai s oundbymeanso heco ela ionsexplainedabo e.
In apa icleDi usioninPo ousCa alys Pa iclesusedinSCSun lowe OilHyd ogena ion
128
Table4‐10:Molecula di usi i ies o C3H8‐T iglyce idesandC3H8‐H2unde se e al
ope a ingcondi ions.
Molecula Bina yDi usionCoe icien D12(m2/s)
C3H8‐T iglyce idesx108C3H8‐H2x107
Tempe a u e
(K)
P essu e
(MPa)
ρC3H8
(kg/m3)Ca chpoleand
King
SunandChenSa e ield
457.1520.03771.621.513.21
457.1527.54480.830.852.34
484.1520.03001.921.803.58
484.1527.54081.251.112.61
Asexpec ed, hemolecula di usi i ycoe icien s o C3H8‐T iglyce idesandC3H8‐H2
pai sinc easewi h empe a u ea cons an p essu e.This iseisp opo ional oTm
whe emisa ound2 o C3H8‐H2and3 o C3H8‐T iglyce idespai andmaybedue o
hedec easein hesol en densi yassocia edwi h heinc easeinsys emp essu e
(A unaja esane al.,2003).
Themolecula di usi i ycoe icien sa ein e selyp opo ional o hemola olumeo
hesolu e.Ascanbe ealized omTable4‐10, he iglyce idesseem odi usea a
slowe a e hanhyd ogeninSCp opaneunde simila expe imen alcondi ions.
Thegene al endobse edis ha hemolecula di usi i iesdec easewi hinc easing
p essu ea cons an empe a u e.I was ound ha hemolecula di usi i iesa e
in e selyp opo ional o hesys emp essu e(D12αP‐1).Thein luenceo p essu eis
essen ially hecombina iono changesin he luiddensi yand iscosi y.As hedensi y
o he luidinc eases, hemola olumedec eases.Insuchsi ua ion,collision ans e ,
a he hanmolecula ans e ,becomes hedominan anspo mechanism.This
esul sinamo ee a icpa h akenby hesolu emoleculeandconsequen lyinasha p
declineindi usi i ysugges inganin e se ela ionshipbe weendi usioncoe icien
andsol en densi y,asshowsinFigu e4‐7.
Chap e Fou
129
-20
-19
-18
-17
-16
-15
250 300 350 400 450 500
ρ (kg/m
3
)
Ln D
12
(m
2
/s)
DC3H8- iglyce ides
DC3H8-H2
Figu e4‐7:Es ima edmolecula di usi i yo hyd ogenand iglyce idesinSCC3H8.
Using hees ima edmolecula di usi i y alues o C3H8‐T iglyce idesandC3H8‐H2
pai s, he a ioo hemolecula di usi i y o hee ec i edi usi i yunde se e al
ope a ingcondi ionswasde e minedwi h he i edexpe imen ale ec i edi usi i ies.
Theob ained aluesa eshowninTable4‐11.
Table4‐11:De/D a io o iglyce idesandhyd ogeninSCp opaneon2%Pd/C.
Reac ion
Tempe a u e(K)
P essu e
(MPa)(De/D)T iglyce ides(De/D)H2
457.1520.01.950.20
457.1527.52.030.19
484.1520.05.440.56
484.1527.55.630.50
Ascanbeseen omTable4‐11, he(De/D)H2ismuchless han heuni ywhichsugges s
ha o hyd ogenonly hebulkdi usioncon ibu es o hemass anspo a ewi hin
hepa icle.Thisisalogicalconsequencebecausehyd ogencandi usemuchmo e
eely han he iglyce idesdue oi slowe molecula size(seeFigu e4‐8).Thea e age
alueso (De/D)H2(be ween0.07‐0.14)ob ained omTable4‐1 o se e al
hyd ogena ionsa 6.5MPao e awide angeo empe a u es(Bu ,1999)a equi e
simila o hose epo edin hiss udy.
Calcula ingTe na y,Vapo ‐Liquidequilib iaUsingThePeng‐RobinsonEqua iono S a e
232
3. C ea ea luid( lowshee
→
adds eam):De ine he empe a u e,p essu easwell
as he lowcomposi ion(speci ymola o weigh pe cen ages).
4. S a calcula ions(Simula ion
→
S a calcula ion).
Dewandbubblecu esda a o he e na ysys emDME+hyd ogen+sun lowe oila
453.15Kand20MPaa e epo edinTableE‐1andVLEa eplo edinFigu eE‐1.
TableE‐1:Dewandbubblecu esda a o he e na ysys emDime hyle he (1)/Hyd ogen
(2)/Sun lowe Oil(3)sys ema 453.15Kand20MPa,xdeno esei he liquido apo phase
mole ac ion.
x(1)x(2)x(3)Vapo
F ac ion
0.00001.00000.00001
0.10000.90000.00001
0.20000.80000.00001
0.30000.69990.00011
0.40000.59990.00011
0.50000.49990.00011
0.60000.39960.00041
0.70000.29650.00351
0.71000.28560.00441
0.72000.27450.00551
0.73000.26230.00771
0.74000.24930.01071
0.74000.20260.05740
0.73000.20270.06730
0.72000.20350.07650
0.71000.20470.08530
0.70000.20600.09400
0.60000.22400.17600
0.50000.24250.25750
0.40000.25960.34040
0.30000.27530.42470
0.20000.28980.51020
0.10000.30340.59660
0.00000.31610.68390
AppendixE
233
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0
0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0 0,0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1,0
453 K
20 MPa
Sun lowe
Oil
H2
DME
Figu eE‐1:Dewandbubblecu es o he e na ysys emses ima edwi h hePR‐EOS(see
Sandle ,1999):Dime hyle he (DME)/Hyd ogen(H2)/sun lowe oilsys ema 473.15Kand20
MPa.Inmol%.
235
AppendixF
Es ima iono T anspo E ec s.
Asubs an ialnumbe o ap io ic i e ia o hees ima iono anspo e ec son
ca aly ic eac ion a eshasbeen epo edbyanumbe o wo ke s.Thesec i e iaa e
gene allyde i edon hep emise ha onedoesno desi e hene anspo e ec o
al e he ue a ebymo e hansomea bi a ilyspeci iedamoun ,no mally5%.
Becauseo heunce ain yin ol edinknowingsomepa ame e s, hephilosophyin
applying hesec i e iashouldbeconse a i e.
Asumma yo appliedin apa icle anspo c i e iaisgi enas ollows.Thesec i e ia
ensu e heabsenceo anye ec s(combined)o empe a u eandconcen a ion
g adien sbu dono gua an ee ha hismayno bedue oacompensa ionbe ween
hea ‐andmass‐ anspo a es.
Requi edExpe imen alDa a
T=484.15K
P=20MPa
Pa iclesize=0.92mm henRp=L/2=0.46mm o aslabgeome y
‐ ’H2,obs==2.26x10‐4mol/(kgs)
De,H2=2x10‐7m2/s
ρp=640kg/m3
CH2,s=1.56mol/m3
ke =2.09x10‐4(KJm)/(sK) omBu (2000)
Re=592.93
kg=1x10‐2m/s omPuiggenée al.(1996)
h=0.2(KJm2)/(sK) omVelo(2003)
ΔH =‐121KJ/mol omVeldinske al.(1997)
Es ima iono T anspo E ec s
236
In e phase anspo empe a u eg adien (Le enspiel,1999).
ʹ
2,
max,
(.)()
0.04º
Hp
obs
ilm
L H
TC
h
ρ
−−∆
∆= = (F.1)
In apa icle anspo empe a u eg adien (Le enspiel,1999).
,22,
max,
()
0.18º
eH H
s
pelle
e
DC H
TC
k
−
∆
∆= = (F.2)
The alueses ima edabo eshow ha hepelle emainsp ac icallyunde auni o m
empe a u e.
In e phase anspo (iso he mal)concen a iong adien (Le enspiel,
1999).
ʹ
ʹʹʹ
2,
2,
1
234
Hp
obs
obs
Hg
gs
L
kL
kCk
ρ
−
==
(F.3)
Theob ained a ioallows oconclude ha he a eo eac ionisno a ec edbymass
ans e esis ance h ough he ilm.
In apa iclemass anspo limi a ion(iso he malpa icle)(Smi h,1981).
TableF‐1:E alua iono in apa iclemass anspo limi a ion.
Pa iclesizedp(mm)
Globalobse edH2
Reac ion a e
(mols‐1kgca ‐1x104)
’H2,obs.dpx104
0.922.262.08
0.473.481.94
As e lec s hep oduc be ween heobse ed a eand hepa iclesize,i isclea ha
hedi usionwi hin hepo ouspelle hasin luenceon he a eo eac ionaswellas
makesi diminishes.
Nomencla u e
CH2,sconcen a iono hyd ogena ca alys su ace[mol/m3]
De,H2 e ec i edi usi i yo hyd ogen[m2/s]
AppendixF
237
dpsphe icaldiame e o pa icle[mm]
hhea ans e coe icien [KJ/(m2sK)]
H hea o hyd ogena ion eac ion[J/(molK)]
ke hea conduc i i yo heca alys pa icle[(KJm)/(sK)]
kggas‐sideo e allmass ans e coe icien [m/s]
Lslab hickness[m]
Pp essu e[MPa]
ReReynoldsnumbe
Rppa icle adius[mm]
’H2,obsobse ed eac ion a eo hyd ogenpe masso ca alys [mol/skg]
T empe a u e[K]
G eekSymbols
ρppelle densi y[kg/m3]
239
AppendixG
Es ima iono Molecula Di usi i ies.
Themolecula di usi i ies o oilandhyd ogeninsupe c i icalp opanewe e
es ima ed.In hecaseo iglyce ideswasemployed heCa chpoleandKing(1994)as
wellas heSun‐Chen(1987)co ela ionsinnea c i ical luids.
F om heda aob ainedunde condi ionso ace di usiono i ea oma ic
hyd oca bonsine hanolandsupe c i icaln‐hexane,SunandChen(seeReide al.1987)
ha ede elopedbymul iple eg essionsanempi icalco ela ion o hemolecula
di usi i yin he o m:
8
0.799 0.490
2.29 10
cc
Dx
TV
µ
−
=(G.1)
whe eDis hemolecula di usi i yo hesolu e,μcis he iscosi yo supe c i ical
luidandVcis hec i ical olumeo solu e.
TheCa chpoleandKing(1994)co ela ioncanes ima e hemolecula di ussi i iesina
angeo nea c i icalsol en so e hesol en educeddensi y1‐2.5,wi hana e age
e o o ±10%.Theco ela ionisno sui able o es ima ingbina ydi usioncoe icien s
a hebina ymix u ec i icalpoin whe edi usioncoe icien ends oze o(B unne ,
1994).
The inalbina ydi usioncoe icien co ela ionisas ollows:
2
3
12 5.152 ( 0.4510) 1 2.5
c
R
DDT whe e
X
ρρ
−
=− <<(G.2)
whe eT andρ a e he educed empe a u eanddensi yo hesol en espec i ely,
Dcis hesel ‐di usioncoe icien a hec i icalpoin ,Xis hesize omasspa ame e
andRis heco ec ion ac o .
Thesel di usioncoe icien a hec i icalpoin ,Dc,canbees ima ed omamodi ied
empi icaldi usioncoe icien co ela ionin e mso hec i icaldensi y(Ca chpoleand
King,1994):
1
70.75
2
2
3
4.300 10 c
c
c
xMT
D
ρ
−
=∑(G.3)
Es ima iono Molecula Di usi i ies
240
whe eMis hemola massing.mol‐1,Tcandρca e hec i ical empe a u eanddensi y
o hesol en inKandkg.m‐3 espec i elyand
∑
a e hedi usion olumesgi enin
Reide al.(1987).
Asize omass a iopa ame e Xisde inedby
1
2
23
1
1
12
2
(1 ( ) )
(1 )
c
c
V
V
XM
M
+
=
+
(G.4)
whe e1is hesol en ,2is hesolu e,Vciis hec i ical olumeandMiis hemola mass.
Risgi enby heequa ionsas ollows:
1.0 0.1 2RwhenX=± <(G.5)
0.17 0.1 2 10RX when X=± <<(G.6)
The equi edda a o de e mining hemolecula di usioncoe icien o C3H8‐
T iglyce idespai isp esen edas ollows:
Requi edDa a
TcC3H8=369.8K
ρcC3H8=369.8kg/m3
MC3H8=44.094g/mol
VcC3H8=203cm3/mol
μcC3H8=228μp
DcC3H8=6.775x108m2/s
MSun lowe Oil=875g/mol
VcSun lowe Oil=3261cm3/mol
Fo hecaseo hesol en , heda ais aken omCa chpoleandKing(1994)and o he
sun lowe oil; heda awases ima edinAnnexB.
Themolecula di usi i y o H2inSCp opanewasde e minedbasedon he
expe imen al alue epo edbySa e ield(1970).Fo hep opane‐H2gaspai a NTP
AppendixG
241
condi ions,D12P=0.45x10‐4m2/s.The e o e,amolecula di usi i yin he angeo 10‐7
m2/sisexpec ed.
Thees ima edmolecula di usi i ycoe icien s o C3H8‐T iglyce idesandC3H8‐H2
pai s oundbymeans heco ela ionsexplainedabo ea ep esen edas ollowing:
TableG‐1:Molecula di usi i ies o C3H8‐T iglyce idesandC3H8‐H2unde se e al
ope a ingcondi ions.
Molecula Di usionCoe icien D12(m2/s)
C3H8‐T iglyce idesx108C3H8‐H2x107
Reac ion
Tempe a u
e(K)
P essu e
(MPa)
ρC3H8
(kg/m3)Ca chpoleand
King
SunandChenSa e ield
457.1520.03771.621.513.21
457.1527.54480.830.852.34
484.1520.03001.921.803.58
484.1527.54081.251.112.61
Nomencla u e
Dmolecula di usi i yo hesolu e[cm2/s]
D12di usioncoe icien [m2/s]
Dcsel di usioncoe icien a hec i icalpoin [m2/s]
Mmola mass[g/mol]
Pp essu e[a m]
Rco ec ion ac o
T empe a u e[K]
T educed empe a u e
Vcc i ical olumeo solu e[cm3/mol]
Xsize omasspa ame e
Speci ica ionDa aShee sandAnaly icalP ocedu es
248
P opane.
AppendixH
249
Speci ica ionDa aShee sandAnaly icalP ocedu es
250
AppendixH
251
Speci ica ionDa aShee sandAnaly icalP ocedu es
252
AppendixH
253
Dime hylE he (DME).
Speci ica ionDa aShee sandAnaly icalP ocedu es
254
AppendixH
255
Speci ica ionDa aShee sandAnaly icalP ocedu es
256
0.5%Pd/Al2O3ca alys .
DATASHEETJOHNSONMATTHEY.
0.5%PalladiumOnAluminaSphe esType50B.
TYPICALINFORMATION
Re e ence 0.5R50B
Ac i eMe al/LoadingPalladium(0.5%)
Suppo (Ca ie ) γ‐AluminaSphe es
Me alLoca ionEggshell
Me alS a e Me al
Su aceA ea 320m2/g
Me alA ea 1.0m2/g
Suppo Diame e 2‐4.75mm
Appa en BulkDensi y 0.75g/cm3
Po eVolume0.45cm3/g
TYPICALAPPLICATIONS
Remo alo O2 omH2,N2,A ,Ai e cbycombina ionwi hH2.
Vapou PhaseHyd ogena ions.
Vapou PhaseDehyd ogena ions.
Re e enceNumbe JM/CPC/0.5R50BDATA02/0695S
Da e 01/06/95
AppendixH
257
2%Pd/Cca alys .
DATASHEET
Palladiumonac i a edca bon3614
Fixedbedca alys ,Me alloca ion:Uni o m
E154XKP/D2%
Ma e ial‐No.:48.7821.4010.00
Cha ac e is icPhysicochemicalValues
Uni sTypical
Values
Palladiumcon en %2.0
Tappeddensi yg/l360
A i ion%1.1
Speci icsu acea eam²/g1530
To alpo e olumeml/g1.30
Valid om:07.02.2000T ialp oduc
Publica ions
264
Gas‐PhaseSun lowe OilHyd ogena ioninHighP essu eP opane:P elimina y
Kine icsinanIn e nal‐RecycleCSTR.
E.Ramí ez,A.S.Oli ei a,M.A.La ayoz,F.Recasens(2003).
P oceedingso 4 hEu opeanCong esso ChemicalEnginee ing,(ECCE‐4),G anada,Spainand
Elec onicVe siononWiley‐In e Science(www.ce ‐jou nal.de).
Abs ac :Thekine ics o sun lowe oilhyd ogena iononPd/Cinasinglephaseusing
densep opane,we ein es iga edinag adien less ixedbed eac o ope a inginawell‐
mixedwayunde awide angeo empe a u es(428‐488K),H2molconcen a ions(2‐
10%), o alweigh hou lyspace eloci ies(WHSV)o ≈2000h‐1ands i e speed(500‐
2500 pm).The o alsys emp essu e, hemola oilconcen a ionand heca alys
weigh we ekep cons an a 200ba ,1%and0.1085g, espec i ely.C ushedca alys
wasemployed.
Thep oposedkine icmodel o he ege ableoilwasbasedon hegene al
hyd ogena ionschemewhichconside sconsecu i e eac ionso heunsa u a ed
iglyce ides oge he wi h hecis‐ ansisome iza iono monoenes.
Simpli iedkine iclawequa ions o heabo e eac ionne wo k oge he wi h he
conse a ionequa ions o aCSTRa s eadys a eandwo kingiso he mally,we eused
omodel hegashyd ogena ion eac ion o allcomponen s(linoleic,oleic,elaidic,
s ea icacidandhyd ogen)as ollows:
0
0
=
+
−
jjj V FF
∑∑ ==
±== q
ijHij
q
iijj CCk
1
2/1
12
Thenonlinea sys emo equa ions o hecomponen sin heCSTRwassol edwi h he
New on‐Raphsonalgo i hmand hekine iccons an aluesob ainedby i ing he
Publica ions
265
eac an concen a ionsdo eachspace eloci y.Toes ima e hekine iccons an s he
expe imen al eac o ou le concen a ionso each eac ioncomponen we econside ed
o he a iousope a ingcondi ions.
The esul ssugess ha k11andk12 aluesa eclose oze odue o helowexpe imen al
con e sionwhe eas heo he cons an sp o ideadesc ip iono heexpe imen alda a
in helowcon e sion ange.Valueso hekine iccons an sa egi en.
Pd‐Ca alysedHyd ogena iono Sun lowe OilinSCP opane:Designo
Expe imen sinaWellMixedCon inuousReac o .
E.Ramí ez,F.Recasens,M.Fe nández,M.A.La ayoz(2003).
P oceedingso 6 hIn e na ionalSymposiumonSupe c i icalFluids,Ve sailles,F ance.
Abs ac :In hispape ,we epo onas udyo hee ec o hesupe c i ical‐sol en
p ocesscondi ions( empe a u e,H2molcomposi ion,liquidhou lyspace eloci y
(LHSV)ands i e speed)on he ansacidcon en and heex ensiono singlephase
sun lowe hyd ogena ion(exp essedby heiodine alue)inaCSTR eac o usinga2%
Pd/Casca alys andSCp opaneasa eac ionmediumino de oassess hem.155‐215
ºC,30‐70h‐1,2‐10H2mol%,500‐2500 pmwe e heexpe imen al angeso he
ope a ional a iables.Theobse ed endsshown heg ea in luenceo a iable
in e ac ions(e.g.LHSV‐H2%andT‐H2%)on hedesi able esponseswhe eas hes i e
speedisnegligible o he eloci y anges udied.
Sun lowe OilHyd ogena ioninSCFinaCon inuousReac o :P elimina y
Expe imen alResul s.
E.Ramí ez,M.A.La ayoz(2002).
P oceedingso 4 hIn e na ionalSymposiumonHighP essu eP ocessTechnologyand
ChemicalEnginee ing,Venice,I aly.
Abs ac :Con inuousinasingle‐phasehyd ogena iono sun lowe oilonPd/Cwas
ca iedou inaRobinson‐Mahoney ype, ixedbedca alys eac o usingp opaneasSC
sol en o eac ion.Di e en p ocesscondi ions( o alsys emp essu e, empe a u e,H2
pa ialp essu eandmola eedmix u ecomposi ion)we es udied oe alua e hei
Publica ions
266
in luenceon heendhyd ogena ionp oduc s.Thephasebeha io o he e na ysys em
was heo e icallyde e minedusingaPengRobinsonequa iono s a eandphase
equilib iumso wa e(PE2000)ino de oassu eonesinglephaseo he eac an
mix u ea heexpe imen alcondi ions.Resul sshow ha i ispossible oob ain
di e en dis ibu ionsandcha ac e is icso he inalhyd ogena ionp oduc sonly
changing heope a ional a iables.
Hyd ogena iono O ganicsinSCSol en s:P elimina yDa aonCa aly icRa es.
E.Ramí ez,M.ALa ayoz,F.Recasens(2001).
P oceedingso IV hB azilianMee ingonSupe c i icalFluids,Sal ado deBahia,B azil.
Abs ac :In hispape we epo on heexamina iono hyd ogena iono o ganic
subs a esonsuppo edPdca alys spublisheddu ing helas ewyea s.Mos o en
au ho s1‐7ha eusedcon inuous low eac o s.Unde hesecondi ions,hyd ogen
con e sioncangi eanideao hes eadys a e a eo hyd ogena ion.Inmos
publica ions,howe e ,ba chda aa e a he di icul omeasu e,in e p e ,andanalyse
as he a eo eac ionchangeswi h imein he essel.Ino de olooka he
hyd ogena ion a es,se e alau ho swe eexamined.Theda ao Polyako andco‐
wo ke s2onse e alsubs a es, ha o Vande Ha kandHä öd4and heda ao
Be uccoe al.5‐6,ha ebeenconside ed.Appa en ly,only he unso Poliako 2and
Hä öd4we epe o medin he apou phaseand heyseemqui econsis en .
Thehypo hesiso hecalcula ionswe e: a eis akenp opo ional ome alloading,
well‐mixed luid,hyd ogenpa ialp essu ea eac o exi wasusedinkine ic
conside a ions,and, hi dly,asligh empe a u eco ec ionwasallowedco esponding
asmallac i a ionene gy(E=10.000kcal/mole).Excep in he ubula eac o o
Be ucco5‐6,whe emul iphase,gas/liquid lowwasp esen , heope a ingcondi ionso
heo he au ho sco esponded ohomogeneous low.Ve y ecen ly,howe e ,Couchi
andco‐wo ke s9d awa en ion o he ac ha heliquidphaseinc eases he a eo
hyd ogena iononPd/Cca alys wi hCO2assol en .
Ou esul ssugges he ollowing:1)Fo mos subs a es,hyd ogena ion a esinSC
CO2a ein heo de o 2‐12molH2/gPd/h, o LHSVo up o30h‐1,basedonca alys
olume.These aluesinc easebyabou 50%inp opane ela i e oca bondioxide.In
Publica ions
267
bo hcases, hepa ialp essu eso hyd ogena ea ound25ba .Theca alys loading
may a y om1 o5%Pdonac i a edca bon.
Theabo e alue o he a es ep esen show as onecanexpec hyd ogena ion o
p oceedinSCF.Incon as , heda ainlow‐p essu eba chandcon inuous
hyd ogena ions,indica e ha he a esa emuchlowe .Fo icklebedope a ion7,wi h
hyd ogen‐sa u a edliquid eed, hemaximum a eon0.75%Pd/Alumina,is0.38mol
H2/gPd/h, o aLHSVo abou 1000h‐1.Fo hecaseo aslu y eac o 8,assumingan
a e agelinedou p oduc i i y, he a eissomewha highe ,i.e.1.3molH2/gPd/h.On
heo he hand,Tackee al.,sugges ha o undisclosedhyd ogena ioncondi ions
(specialca alys sizeo hyd ogenp essu e)maylead ola ge space imeyields.
Hyd ogen a esseem obep opo ional opa ialp essu eo hyd ogensokine ic
cons an couldbees ablished o someo hesubs a es.Unce ain yonkine icsdoes
no allow a ou ingahal o de wi h espec ohyd ogenasiscommonin
hyd ogena ionwi hhyd ogenadso p ionwi hdissocia ion.
Hyd ogena ion eac ionsinSCsol en s.
S.Zga ni,E.Ramí ez,A.La ayoz,F.Recasens(2001).
P oceedingso Explo a o yWo kshoponSupe c i icalFluidsasAc i eMedia:Fundamen als
andApplica ions,Valladolid,Spain.
Abs ac :Ino ganicsyn hesesSC luids i e ywellasg een,sus ainablesol en sin
cleanchemicalp ocessingingene al(Busch,2001)andpa icula lyinsomeindus ial
polyme iza ions(DeLissie al.,2000;Ajzenbe ge al.,2000)andinca alys egene a ion
p ocesses(T abelsie al.,2000).In hesep ocesses he luidcanbecheaplyand
e icien ly eco e ed om he eac o and ecycledwi hanegligibleen i onmen al
impac onand e yli leene gyexpendi u e.Recen ly,anin e es ingaccoun on he
useo SCFincleanca aly ic eac ionshasbeenpublishedinamagazine(F eeman le,
2001)wi hse e alo o ganicp ocesses ha couldbene i omSCF,includingsolid‐
ca alysedhyd ogena ions.
Ca bondioxideis hep e e ed he luid o cleanchemicalp ocessing.Howe e ,i
mayno be hebes luido choice.Fo example, heope a ingp essu esand
empe a u es o CO2a e a oohigh o each hec i icals a eo he eac ingmix u e.
Publica ions
268
In his ega d,somewo ke s(Pe edaandco‐wo ke s,2000,deJonge al.2001)
compa edCO2wi hlowe alkanes o hehyd ogena iono mul ipledoublebondsin
e mso mul iphaseequilib ia.
Hi zle andcoau ho s epo onanewme hod o con inuousca aly ichyd ogena ion
(inCO2andinp opane)onsuppo edPd.Awide angeo subs a esincludingalkenes,
alkynes,ke onesandaldehydes,epoxides,phenols,ni iles,e c.,wasexamined.An
impo an indingis ha heope a ingcondi ions( empe a u e,p essu e,
hyd ogen/subs a emole a io)canbe uned od i e eac ion o hedesi edp oduc
dis ibu ion.Thescaleo ope a iono Hi zle e al.wasa5‐mL eac o .Inasimila way,
Hä ödandco–wo ke s,s udied hehyd ogena iono a sandoilsno inga e yhigh
a esand educedbyp oduc o ma ion ha canbeob ainedin ixedbed eac o
ope a inginasinglegasphase.La ge eac ion a eswe eexplainedin e mso he
highe hyd ogeng adien sex e nal o heca alys pa icle,ascompa ed o hecaseo
wo‐phase low.Whe e as e hyd ogen ans e a escouldalsoplaya ole.Be uccoe
al.alsos udiedhyd ogena ionkine icso o ganicsonPd/CinaCSTRBe y‐ ypeo
eac o usingSCCO2assol en .Thesys emwasclea lysubjec phasesepa a ion
du ingope a ion.Aninc easein a ewasalsoobse edwhenaliquidphaseappea ed
al hough he a eenhancemen wasless han ha obse edbyHä öd.De e ae al.
alsos udied hehyd ogena ionp ocessina ickle‐bed eac o aslowp essu e
al e na i e.
Mo e ecen ly,Chouchie al.,ga ep elimina yda aon he esul so hyd ogena iono
α‐pineneonPd/CinSCCO2inas i edba ch eac o .Againi was ound ha he
la ge a esde elopedwhene e a wo‐phasesys emwas isuallyobse ed.One‐phase
and wo‐phasesys emsshowed e ydi e en a es.
In hiswo kwe e iewsomeo hesolidca alysedhyd ogena ionp ocesseswi haSCF
sol en .Ra e aluesa ecompa edwi h hose o low‐p essu eslu yand ickle‐bed
eac o swhe esomeo hecon en ionalhyd ogena ionsa eca iedou .Wewan o
seealsoi he ea ead an agesinusingSCFsol en sas ega ds o heselec i i iesand
hep esenceo mul iplephases.
Publica ions
269
Jou nalA icles.
Sun lowe OilHyd ogena iononComme cial‐SizePdPa iclesinSupe c i ical
Fluids:Sol en andCa alys TypeE ec sonKine icsandSelec i i ies
M.A.La ayoz,E.Ramí ez,A.San anaandF.Recasens.
JAOCS,submi ed,2005
In oduc ion:Supe c i ical luid echnologyisbecomingimpo an in helipidand ood
indus yina a ie yo ields.So a , heemphasis,howe e ,hasbeenonex ac ion
p ocesses(KingandLis ,1996).Reac ionandca aly icapplica ionslagwellbehind
(Sub amaniamandMcHugh,1985;B unne ,2003).Fo ce ainindus ial
polyme iza ions(Azjenbe ge al.,2002),ahighpo en ialhasbeenshown oexis .In
gene al, hebene i so SCFinhe e ogeneousca alysisha ebeenemphasizedince ain
isome isa ion eac ionsin ol ingcokedeposi ionand o enhancingin apa icle
di usion(McHughandK ukonis,1994).Inca aly ic eac ions,hyd ogena ions ands
among hemos impo an eac ionsinpe oleump ocessesandin he oodand ine
chemicalindus ies(Fa au oandBa holomew,1998).In hispape weexamine he
hyd ogena iono sun lowe oilin luids,suchasSCp opaneandSCdime hyle he
(DME),andonce ainPd‐basedca alys susinganumbe o suppo s.Amain
ad an ageo suchhighp essu esys emsis ha eac ionscanbeca iedou in he
apo phaseinacon inuous‐ low eac o (Ramí eze al.,2003).Fo edibleoil
hyd ogena ion, hisisanimp o emen .
Thepu poseo ege ableoilhyd ogena ionis oob ainamo es ablep oduc (no
oxida ionons o age), oge he wi hasui able ex u eandmel ing‐ empe a u e angea
hemou hcondi ions o humanuseasma ga ineandsho enings.Ca aly icslu y
p ocessiscus oma yin he ege ableoilhyd ogena ionindus ywi hnickel(Raneyo
suppo ed),o suppo edPdasca alys s,onano he wisewelles ablishedca alys sand
echnology(Alb igh ,1961;Rase,2000;Fa au oandBa holomew,1997).Incon as ,
he apo phasep ocesseswe ein oducedin he1990sbyHä ödandMölle (1993)
andHä öde al.(2001)chie ly o a yacidme hyles e s(FAME)inp opane(Hä od
andMölle ,1994)usingEngelha dCuca alys sandbyKingandco‐wo ke sa ACAUR
usingSCca bondioxideonsuppo edNi(Kinge al.,2001)inba chs i ed ank
eac o s.In heEU,ea lywo ko Degussascien is s(1993)showed ha eac ioninSC
ca bondioxideusingPdisex emely as and a o able ela i e o he o ma iono
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ansC18wi h iglyce idesasa eed(Tackee al,).SeeRami eze al.,(2002) o a e iew
onca aly ic a esinSCmedia.
T iglyce idesexhibi cis‐ ansisome ic o msinNa u e.When a ycompoundsa e
unsa u a ed, hecisisome is hena u alone.The ansisome appea sdu ing
hyd ogena ion.I unco ec ed, he anscon en inma ga inescanbeasla geas40w %
in hecon en ionallowp essu e,slu y eac o hyd ogena ions(Rase,1979).Al hough
hee ec sonhumanheal ho ansisome sa eno clea , heya esuspec obe
me abolised o heundesi ed(o bad)choles e ol ypesoa ec inghea disease.So a ,
Denma khasbeen heonlycoun yin hewo ldwhe e heMinis yo Heal hhas
limi edbylaw he anscon en oless han2%on a componen s o humaninges ion
sinceMay2003.Thecommi eeo expe sCodexAlimen a iuso heFAOisona
deba e ega ding heinclusiono ans a yacidscon en on oodlabels.On heo he
hand, heEUis a o able oinclude hison helabel,bu legalac ionisye obe aken.
In heUS, hego e nmen ( h ough heFDA)haspu o wa dacampaign(announced
by heSu geanGene alin2003) olabelbylaw he% anscon en and he%sa u a ed
a ,be o e2006.Thee o so Kingandco‐wo ke s(2001) ode elopalow ans
p ocessa heFDA,a ein hisdi ec ion.
Inap e iouswo k,weha eused heme hodologyo hedesigno expe imen sand
esponsesu acemodels oachie eop imumhyd ogena ioncondi ions o Pdca alys
inSCp opaneinaCST eac o .Bymodelling hesys em esponseempi ically,Ramí ez
e al.,(2004)showed ha i waspossible oob ainahyd ogena e a wi hless han2,5%
anscon en inonepass h ough he eac o inacon inuousp ocess,wi haiodine
alueo abou 70(s a ingwi ha alueo 130).T iglyce idesun lowe oilwas he aw
ma e ial.Fu he mo e,simplekine icsusings anda dkine icsp o ided he a e
cons an son hePd/Cca alys .
In hiswo kwehad a iouspu poses.Fi s ,wewan ed omeasu ehyd ogena ion
kine icsonPd/Cca alys pelle so comme cialsize(0.55mm),usingp opaneandDME
asSCsol en s.AneggshellPdca alys wasalsoexamined.Theo he pu posewas o
simula e eac o ope a ionwi h hekine icssode elopedino de osee eac o
pe o manceandcompa ewi hexpe imen .
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In apa icleDi usionMechanismsinSupe c i icalSun lowe OilHyd ogena ion
onPd/CCa alys .
E.Ramí ez,M.A.La ayoz,F.Recasens
AIChEJou nal,unde e ision,2005.
Abs ac :We epo on hePdca alyzedhyd ogena iono ege able(soya,sun lowe ,
palm)oil,animpo an p ocess o ob ainingul alow ans‐C18:1ands ea icC18:0
p oduc s(2.5w %and19w %, espec i ely, o sun lowe oil), obeusedaslow
choles e olp ecu so s o ma ga ineandsho eningbasesin henex ewyea s.
Fu he ,i single apo phasecondi ionsa ea ained,acon inuousope a ionispossible
making hep ocessqui einno a i e.In hiswo kweconside heope a ionin
supe c i icalp opane.Thisisaplen i ul,inexpensi e, ola ilesol en ha canbe
eco e edalmos comple ely.O he SCgasesa eno excluded.
Reac ion unswe epe o medona ecycle eac o a aweigh hou lyspace eloci yo
300‐900h‐1,basedonmasso ca alys (2%PdonAC).Feedconcen a ionsa e1,4,95
mol%(oil,H2,C3H8),and eac o condi ions210ºCand275ba .Suchcondi ionsallowa
non‐condensingo single apo phase.Ou in e es was odecouplein insickine ics
om eac an di usi i ies, o a a he complexne wo ko hyd ogena ionsand
hyd oisome isa ions ha occu simul aneously.Weused heWei(1962)concep o he
di e en ialequa ion ec o ,usinghowe e anume icalsolu ionapp oachcombined
wi hnonlinea pa ame e i ing.Fi s , eac ion unspe o medonsmallsizeo ca alys
(0.4mm)allowed oob ainkine iccons an si espec i eo hedi usi i yse ings.
Then,inasecondse o uns, eac ionswe e epea edonla ge sizeo ca alys (up o
1mm), ha is,in hedi usion‐limi ed egime.In hissecondse o uns hedi usion
coe icien o hyd ogenand he iglyce ideswe ee alua edby i ing heexpe imen al
di usion luxes.Inbo hse so expe imen al uns, heiodine alue educ ionwasa
leas 44%.Onlyonedi usioncoe icien wasconside ed o all he iglyce ides,as hei
mwa esimila .
The esul sshown ha whilehyd ogenis anspo edbybulkpo edi usion; heoil
componen sseem odi usebysu acedi usion,in iewo hes ongsu acedi usion
dependenceo pandT.As ega ds ohyd ogena ion,pa icleso 0.1mma ekine ically
con olled,bu hee ec i eness ac o alls o0.3 o 1mmpa icles.I isalsoseen ha
ha hedi usi i ies o glyce idesinliquid illedpo es(s anda dslu yp ocessa low
p essu e)a emuchlowe hanin heSCF,making eac ion e y apidin hissol en .
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Di usi i yo H2isabou 10 imes hano iglyce ides,despi eo he ac ha he
molecula weigh o hela e is~500 imes ha o H2.Thismeans ha hesu ace
mig a iono iglyce idesiss ill e y as .Theo e alldi usi i y o iglyce idesis
abou 10‐8m2/s,andchanges3 imeswi haninc easeinp essu e,and20 imeswi han
inc easeinT.Also,linolea eselec i i yandisome isa ionyieldalsoimp o ewi h
dec easing hedi usionpa h(Campse al.,2004).
Keywo ds:Fa hyd ogena ion,sun lowe oil,supe c i ical luids,p opane, ans‐
con en ,kine ics,in apa icledi usion,palladiumca alys ,ca bonsuppo .
Hyd ogena iono Sun lowe OilonPd/CinSupe c i icalP opane:Ope a ing
Condi ionsinaCon inuousIn e nalRecycleReac o .
Ramí ez,E.,Recasens,F.,Fe nándezM.andLa ayozM.A.
AIChEJou nal,50,6(2004).
Abs ac :Fluid‐phase,con inuoushyd ogena ionso sun lowe oilon2%Pd/Cwe e
ca iedou inanin e nal ecycle, adial‐ low,packed‐bedmic o eac o (50cm3)using
p opaneassupe c i ical‐ luidsol en .Tempe a u e(428–488K),oilliquidhou lyspace
eloci y(LHSV30–70),H2molcomposi ion(2–10%),ands i e speed(52–262 ad/s)
we echangedacco ding oa ou ‐ a iable, wo‐le el,cen alcomposi edesign o
p edic hee ec o p ocess a iableson heiodine alue(IV)andon ans a yacid
con en ( ansC18:1).Feedandp oduc we ewellabo e hecondensa ioncondi ionsso
ha asingle luidphasewasp esen (acco ding o ecen calcula ionsbyPe edae al.).
The o alsys emp essu e, hemola oilconcen a ionand heca alys masswe eheld
cons an a 20MPa,1mol%,and0.1085g, espec i ely.Anempi icalquad a ic‐ o m
esponsesu acemodelisshown o i he esul s,andshows he egionswhe ea
po en ialCSTRp ocesscouldbeope a ed oob ainace ainou le iodine alueanda
minimum ansC18:1con en .Fo he ime‐ons eam aluesusedhe eca alys
deac i a ione ec swe eno obse ed.Inanex ensiono he esul s,akine icanalysis
o hes eady‐s a eCSTR eac ion a eda aallowsde e mina iono hekine ic
cons an s,and hei empe a u edependency, o hemul iple eac ionso
hyd ogena ion–isome iza ionne wo kin ol ing iglyce idespecies.Thekine ic
o malism,p oposedea lie o ege ableoilhyd ogena ions,wasused.
Keywo ds:hyd ogena ion, ege ableoil,supe c i ical luidsol en s,phaseequilib ia,
expe imen alcen alcomposi edesign, esponse‐su aceme hodologykine icsonPd
ca alys .
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Sho Compila iono PublishedRa eDa a o Ca aly icHyd ogena ionsin
Supe c i icalFluids
Ramí ez,E.,S.Zga ni,M.A.La ayoz,andF.Recasens.
Chem.Eng.Technol.Jou nal:Enginee inginLi eScience,2,9,257(2002).
Abs ac :In hiswo k,asho compila ionisp esen edonhe e ogeneouslyca alyzed
hyd ogena ionsca iedou innea ‐c i ical luids.Reac ionsca iedou insupe c i ical
luids,ca alyzedbysuppo edPd,Nio Cu,a econside edasg eenp ocessesin iew
o hei negligibleimpac on heen i onmen .Anumbe o echnologiesa eal eady
a ailable o cleanhyd ogena ions,mos lype o medinca bondioxideasadense
sol en incon inuous eac o s.Howe e ,p opaneando he lowe alkanesol en scan
pe o maswellasca bondioxidebu a muchlowe p essu es.We e iew hei
beha io sin hispape in e mso obse ed eac ion a es,space eloci ies,selec i i ies
andappa en kine iccons an s.In hecaseo ege ableoils,da aa ea ailableon he
e ec o p essu eand eac ioncondi ionson heselec i i y owa d hep e e edcis‐
isome du inglinoleichyd ogena ion.
Keywo ds:Hyd ogena ion,he e ogeneousca alys s,supe c i ical luidsol en s,
kine ics,selec i i ies,phaseequilib ia.
Pa en .
Pa ialhyd ogena iono unsa u a ed iglyce idesin apou ‐phasea highp essu e
ina eac o o ca yingou hisp ocess.
Sil iaCampsHe nán‐Pé ez,MónicaFe nándezGa za,MªAngelsLa ayozI ia e,
ElianaRamí ezRangel,F anciscoRecasensBaxa ias&Jo diSansSolé,
P200401793(unde e ision,2004),Spain.
Abs ac :In hispa en ,asingle apou ‐phase ege ableoilhyd ogena ionp ocesson
suppo edPdca alys isdesc ibed.The eedmix u econsis so iglyce ides,hyd ogen
andagaseoussol en a highp essu e.
