BIOFUELSAND BIOREFINING
Volume2:Intensification ProcessesandBiorefineries
Editedby
CLAUDIAGUTIERREZ-ANTONIO
FERNANDOISRAELGÓMEZCASTRO
Elsevier
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ISBN:978-0-12-824117-2
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Contributors
SairaAsif
SustainableProcessIntegrationLaboratory,SPIL,NETMECentre,FacultyofMechanical Engineering,BrnoUniversityofTechnology,VUTBrno,Brno,CzechRepublic;Facultyof Sciences,DepartmentofBotany,PMASAridAgricultureUniversity,Rawalpindi,Punjab, Pakistan
AlexandraBarron
DepartmentofChemicalEngineering,TexasA&MUniversity;GasandFuelsResearchCenter, TexasA&MEngineeringExperimentStation,CollegeStation,TX,UnitedStates
AwaisBokhari
SustainableProcessIntegrationLaboratory,SPIL,NETMECentre,FacultyofMechanical Engineering,BrnoUniversityofTechnology,VUTBrno,Brno,CzechRepublic; ChemicalEngineeringDepartment,COMSATSUniversityIslamabad(CUI),Punjab, Lahore,Pakistan
P.Champagne
Institutnationaldelarecherchescientifique,QuebecCity,QC,Canada
YokeWangCheng
DepartmentofChemicalEngineering,SchoolofEngineeringandComputing,Manipal InternationalUniversity,NegeriSembilan,Malaysia
ChiChengChong
DepartmentofChemicalEngineering,SchoolofEngineeringandComputing,Manipal InternationalUniversity,NegeriSembilan,Malaysia
NatashaChrisandina
DepartmentofChemicalEngineering,TexasA&MUniversity;GasandFuelsResearchCenter, TexasA&MEngineeringExperimentStation,CollegeStation,TX,UnitedStates
LaiFattChuah
FacultyofMaritimeStudies,UniversitiMalaysiaTerengganu,KualaTerengganu,Terengganu, Malaysia
M.Collotta
DIMI,DepartmentofMechanicalandIndustrialEngineering,UniversityofBrescia,Brescia,Italy
GabrielContreras-Zarazu ´ a ChemicalEngineeringDepartment,UniversityofGuanajuato,Guanajuato,Mexico
JulioArmandodeLira-Flores
FacultaddeQuı´mica,UniversidadAuto ´ nomadeQueretaro,CentroUniversitario,Queretaro, Mexico
MarcosR.P.deSousa
UniversityofCampinas,SchoolofChemicalEngineering,Campinas,SP,Brazil
ThiagoEdwiges
DepartmentofBiologicalandEnvironmentalSciences,FederalUniversityofTechnology, Medianeira,Parana,Brazil
MahmoudM.El-Halwagi
DepartmentofChemicalEngineering,TexasA&MUniversity;GasandFuelsResearchCenter, TexasA&MEngineeringExperimentStation,CollegeStation,TX,UnitedStates
MassimilianoErrico
FacultyofEngineering,DepartmentofGreenTechnology,UniversityofSouthernDenmark, Odense,Denmark
YulissaMercedesEspinoza-Va ´ zquez
DepartamentodeIngenierı´aQuı´mica,Divisio ´ ndeCienciasNaturalesyExactas,Universidadde Guanajuato,Guanajuato,Guanajuato,Mexico
ErnestoFlores-Cordero
BiotechnologyEngineeringDepartment,UniversityofGuanajuato,CampusCelaya-Salvatierra, Guanajuato,Gto.,Mexico
JuanFernandoGarcı´a-Trejo
FacultaddeIngenierı´a,UniversidadAuto ´ nomadeQueretaro,Amazcala,Queretaro,Mexico
FernandoIsraelGo ´ mez-Castro
DepartamentodeIngenierı´aQuı´mica,Divisio ´ ndeCienciasNaturalesyExactas,Universidadde Guanajuato,Guanajuato,Guanajuato,Mexico
ClaudiaGutierrez-Antonio
FacultaddeIngenierı´a,UniversidadAuto ´ nomadeQueretaro,Amazcala,Queretaro,Mexico
JunaidHaider
SustainableProcessAnalysis,Design,andEngineeringLaboratory,EnergyandChemical EngineeringDepartment,UlsanNationalInstituteofScienceandTechnology(UNIST),Ulsan, SouthKorea
SalvadorHerna ´ ndez
DepartamentodeIngenierı´aQuı´mica,Divisio ´ ndeCienciasNaturalesyExactas,Universidadde Guanajuato,Guanajuato,Mexico
Noemı ´ Herna ´ ndez-Neri
FacultaddeIngenierı´a,UniversidadAuto ´ nomadeQueretaro,Amazcala,Queretaro,Mexico
Jirı ´ Jaromı´rKlemes ˇ
SustainableProcessIntegrationLaboratory,SPIL,NETMECentre,FacultyofMechanical Engineering,BrnoUniversityofTechnology,VUTBrno,Brno,CzechRepublic
MoonyongLee
SchoolofChemicalEngineering,YeungnamUniversity,Gyeongsan,SouthKorea
NguyenVanDucLong
SchoolofEngineering,UniversityofWarwick,Coventry,UnitedKingdom;SchoolofChemical EngineeringandAdvancedMaterials,UniversityofAdelaide,Adelaide,SA,Australia
AntiocoLo ´ pez-Molina
UniversidadJua ´ rezAuto ´ nomadeTabasco,JalpadeMendez,Mexico
W.Mabee
Queen’sUniversity,DepartmentofGeographyandPlanning,Mackintosh-CorryHall,Kingston, ON,Canada
SergioIva ´ nMartı´nez-Guido
FacultaddeIngenierı´a,UniversidadAuto ´ nomadeQueretaro,Amazcala,Queretaro,Mexico
LeCaoNhien
SchoolofChemicalEngineering,YeungnamUniversity,Gyeongsan,SouthKorea
AlvaroOrjuela
DepartmentofChemicalandEnvironmentalEngineering,UniversidadNacionaldeColombia, Bogota ´ D.C.,Colombia
AndreadelPilarOrjuela
ProcessSolutionsandEquipmentSAS,EngineeringDivision,Bogota ´ D.C.,Colombia
JoseMarı´aPonce-Ortega
FacultaddeIngenierı´aQuı´mica,Divisio ´ ndeEstudiosdePosgrado,UniversidadMichoacanade SanNicola ´ sdeHidalgo,Morelia,Michoaca ´ n,Mexico
CesarRamı´rez-Ma ´ rquez
ChemicalEngineeringDepartment,UniversityofGuanajuato,Guanajuato,Mexico
MariaCintaRoda-Serrat
FacultyofEngineering,DepartmentofGreenTechnology,UniversityofSouthernDenmark, Odense,Denmark
AraceliGuadalupeRomero-Izquierdo
FacultaddeIngenierı´a,UniversidadAuto ´ nomadeQueretaro,Amazcala,Queretaro,Mexico
EduardoSa ´ nchez-Ramı ´ rez
ChemicalEngineeringDepartment,UniversityofGuanajuato,Guanajuato,Mexico
HarrsonS.Santana
UniversityofCampinas,SchoolofChemicalEngineering,Campinas,SP,Brazil
JuanGabrielSegovia-Herna ´ ndez ChemicalEngineeringDepartment,UniversityofGuanajuato,Guanajuato,Mexico
DebalinaSengupta
GasandFuelsResearchCenter,TexasA&MEngineeringExperimentStation,CollegeStation, TX,UnitedStates
ClaireShi
DepartmentofChemistry,RiceUniversity,Houston,TX,UnitedStates
PauLokeShow
DepartmentofChemicalandEnvironmentalEngineering,UniversityofNottingham—Malaysia Campus,Semenyih,Malaysia
Joa˜oL.SilvaJu ´ nior
FederalUniversityofABC,CECS—CenterforEngineering,ModelingandAppliedSocial Sciences,AlamedadaUniversidade,Sa ˜ oBernardodoCampo,SP,Brazil
G.Tomasoni
DIMI,DepartmentofMechanicalandIndustrialEngineering,UniversityofBrescia,Brescia,Italy
StefaniaTronci
DipartimentodiIngegneriaMeccanica,ChimicaedeiMateriali,Universita ´ degliStudidi Cagliari,Cagliari,Italy
Processintensificationinbiofuels production
SalvadorHernández DepartamentodeIngenierı´aQuı´mica,Divisio ´ ndeCienciasNaturalesyExactas,UniversidaddeGuanajuato,Guanajuato,Mexico
1.1Introduction
Throughhistory,thesocietyhasevolvedduetotheresearchandtechnologicaladvances inalltheknowledgeareas.Theseadvanceshaveallowedbetterqualitylifeofthesociety, throughthemedicaladvances,transportationmeans,homecomforts,education,aswell asrecreationalactivities.Eveninthelastdecades,theglobalizationhasmadepossiblethe contactbetweenpeoplelocatedindifferentpartsoftheworld,whichcaninterchange experiences,culture,goods,news,andevenreal-timeeventswithjustaclickonacomputerwithinternetaccess.Alltheseimprovementsandbenefitstothesocietyhasone commonfactor:energy.
In2019,theworldwideenergyconsumptionwas14,406Mtoe(IEA,2020a);this amountofenergyproceedsfromoil(31%),coal(26%),naturalgas(23%),renewables (14%),andnuclear(6%)(IEA,2020a,2020b).Theforecastsindicatedthatthisamount ofenergywouldhaveincreasedin10%for2028(IEA,2020c).However,theforecasts changedduetotheappearanceandspreadoftheSars-CoV-2,whohasmodifiedthe knownworld’sdynamics.Potentialnewpracticesandsocialformsbeingfacilitatedby thepandemicsarehavingimpactsonenergydemandandconsumption,whichhas,in general,declined( Jiang,VanFan,&Klemesˇ,2021).Inspiteoftwovaccineshavebeen successfullydevelopedatanunprecedentedspeed(Huang,Zeng,&Yan,2021),itslargescaleproductionisnowthebottleneck.Nowadays,notalltheworldpopulationhas receivedthevaccine;thereforetherearestillmanyeconomicsectorsthataredetained orwithlowactivity,suchastheaviationsectorwhichrecoveryprocessseemsmuch slowerthananticipated(Dube,Nhamo,&Chikodzi,2021).Itisimportanttomention thatthepandemicsituation,aswellasitseffects,isaconstantlychangingsituation.
Inthiscontext,theInternationalEnergyAgencyhasproposed,incollaborationwith theInternationalMonetaryFund,aSustainableRecoveryPlan(IEA,2020d).Thisplanis focusedonboostingtheeconomicgrowth,creatingjobs,andbuildingmoreresilientand cleanerenergysystems;itisimportanttomentionthatthisplanisintendedtobeimplementedintheperiod2021–23.Theplanincludespolicies,investments,andmeasuresto acceleratethedeploymentofsixkeyareas(IEA,2020d),whichareshownin Fig.1.1.
BiofuelsandBiorefining Copyright © 2022ElsevierInc. https://doi.org/10.1016/B978-0-12-824117-2.00001-6
Boost innovation in technological areas
Development of sustainable biofuels
Enhance efficiency of industrial equipment
Recovery Plan
Accelerate low carbon electricity
Spread cleaner transport
Increase energy efficiency of buildings and appliances
Fig.1.1 SustainablerecoveryplanproposedbytheInternationalEnergyAgencyincollaborationwith theInternationalMonetaryFund.
Fig.1.2 Classificationofbiomassbasedonitschemicalnature.
From Fig.1.1,itcanbeseenthatthedevelopmentofbiofuelsplaysakeyroleinthis SustainableRecoveryPlan.
Biofuelsaredefinedasthosefuelsthataregeneratedfromtheconversionofbiomass, whichisacomplexnaturalrenewablematerialwithenormouschemicalvariability (Bonechietal.,2017).Thebiomassisdefinedasalltheorganicmatteroriginatingfrom livingplants,organisms,aswellassometypesofresiduesfromagricultural,agroindustrial, food,domestic,andothersectors(Pang,2016; Soria-Ornelas,Gutierrez-Antonio,& Rodrı´guez,2016).Biomassisconsideredasuitablesourceforrenewableenergyandbiobasedproductsduetoitsorganicnature,carbonstability,andabundantsupply(Gent, Twedt,Gerometta,&Almberg,2017).Thebiomasscanbeclassifiedaccordingtoseveral criteria,suchasarable,edible,residual,amongothers.Aninterestingclassificationconsideringthechemicalnatureofthebiomassisasfollows:triglyceride,lignocellulosic, sugar,andstarch(Maity,2015)(Fig.1.2).
Bioethanol
Biogasoline
Biodiesel
Green diesel
Biojet fuel
Biogas
Syngas
Biohydrogen
Fuel pellets
Briquettes
Pales
Cubes
Thetriglyceridebiomasscontainsfattyacids(palmiticacid,linoleicacid,ricinoleic acid)andtriglycerides(palmitin,linolein,ricinolein);thistypeofbiomassincludesoils fromsoybean,castorbeanormicroalgae,aswellasfatsfrompoultry,fish,beef.On theotherhand,thelignocellulosicbiomasscontainslignin,cellulose,andhemicellulose asmaincomponents;thistypeofbiomassincludesalltheagriculturalresidues,leaves, wood,grass,aswellasenergeticcrops.Finally,asthenamesuggest,thesugarandstarch biomasscontainpentose,hexose,glucose,amylose,andamylopectin;thistypeofbiomass includessugarcane,potatoes,apples,aswellasotherediblecrops.Thisclassification allowstogroupallthebiofuelconversionprocessesbasedonthechemicalnatureof thebiomass,inspiteofitisedible,nonedible,orresidual.
Thebiomasscanbeconvertedintobiofuelsinliquid,gaseous,orsolidstate(Fig.1.3). Amongliquidbiofuels,thosedestinedmainlyfortransportsectorarefound,suchasbiogasoline,greendiesel,andbiojetfuel;however,theyalsocanbeusedtogenerateelectricityorheat.Regardthesolidbiofuels,themostpopulararethefuelpellets,whichcan beusedtoproduceelectricalorthermalenergy,similartothegaseousbiofuels,among whichbiogasisthemostpopular.
Thebiofuelsareobtainedfromtheconversionofbiomassthroughchemical,biochemical,thermochemical,andbiologicalprocesses(Fig.1.4).Inthechemicalprocesses, thebiomass(orafractionofit)isconvertedthroughasetofchemicalreactions,which wouldrequireadditionalreactants,solvents,catalysts,andmoderatetohightemperature andpressure;examplesofthistypeofprocessaretransesterification,hydrodeoxygenation,hydrocracking,andoligomerization,amongothers.Ontheotherhand,inthe
Fig.1.3 Classificationofbiofuelsaccordingtoitsphysicalstate.
biochemicalprocesses,thelargemoleculesthatconstitutethebiomass(orafractionofit) areconvertedinsmalleronesthroughtheactionofmicroorganisms;thistypeofprocess usuallyrequireswaterandlowtemperatureandpressure.Thefermentation,hydrolysis,as wellasdigestion,arebiochemicalprocesses.
Ontheotherhand,inthethermochemicalprocesses,themainobjectiveisconverting thebiomass(orafractionofit)intogases,liquids,orevensolidcompounds,releasingthe energycontainedinthemasheat.Theheatcanbeuseddirectlyoremployedtoproduce electricity;atthesametime,thecompoundsgeneratedcanbetransformedinothervaluableproducts.Inthermochemicalprocessisrequiredairorinertatmospheresaswellas hightemperatureandpressure.Thepyrolysis,gasification,andcombustionareexamples ofthistypeofprocesses.Finally,thebiomass(orafractionofit)canalsobeconverted throughbiologicalprocesses;inthiscase,thebiomassisusedasfeedfortheorganisms, whichgeneratednewcompoundsasresultsofthedigestionorneworganismswhichcan befurtherprocessedtogenerateothervaluableproducts.Inthiscategory,wecanmentionthecultureofblacksoldierflyaswellasworms.
Itisimportanttomentionthatallbiofuelsarerenewables,sincetheyaregenerated frombiomass;however,theydonotnecessarilyaresustainable,sincethisdependson thekindofbiomassandprocessingroute.Eachoneoftheseprocesseshavedifferentenergeticefficiencies,obtainedproducts,yieldsaswellasoperationandinvestmentcosts.To havebiofuelsthatarerenewableandsustainable,itmustbeensuredthatthewholesupply chainhasreducedcarbonfootprint,withspecialemphasisontheconversionprocesses.
Inthelastyears,researchershavefocusedtheireffortsonthedevelopmentofproductionprocessesfortheproductionofbiofuels.Intheliterature,therearestudiesforthe productionofbioethanol(Ayodele,Alsaffar,&Mustapa,2020; Greetham,Zaky, Makanjuola,&Du,2018; MohdAzharetal.,2017; Sharma,Larroche,&Dussap, 2020),biobutanol(Huziretal.,2018; Ibrahim,Kim,&Abd-Aziz,2018; Wangetal., 2017; Yeongetal.,2018),biogasoline(Hassan,Sani,AbdulAziz,Sulaiman,&Daud,
Fig.1.4 Conversionprocessesfortheproductionofbiofuels.
2015; Mascal&Dutta,2020; Shamsul,Kamarudin,&Rahman,2017),greendiesel (Ameen,Azizan,Yusup,Ramli,&Yasir,2017; Amin,2019; Arun,Sharma,&Dalai, 2015; Kordulis,Bourikas,Gousi,Kordouli,&Lycourghiotis,2016),biojetfuel (Galadima&Muraza,2015; Gutierrez-Antonio,Go ´ mez-Castro,deLira-Flores,& Herna ´ ndez,2017; KandaramathHari,Yaakob,&Binitha,2015; Va ´ squez,Silva,& Castillo,2017),biogas(Pramanik,Suja,Zain,&Pramanik,2019; Alavi-Borazjani, Capela,&Tarelho,2020; Kovacicetal.,2021; Liu,Ren,Yang,Liu,&Sun,2021; Liu,Wei,&Leng,2021),syngas(Aziz,Setiabudi,Teh,Annuar,&Jalil,2019; Leonzio,2018; Ren,Cao,Zhao,Yang,&Wei,2019; Yeo,Ashok,&Kawi,2019),biohydrogen(Fagbohungbe,Komolafe,&Okere,2019; Chen,Wei,&Ni,2021; Dahiya, Chatterjee,Sarkar,&Mohan,2021; Fajı´n&Cordeiro,2021),fuelpellets(Bajwa, Peterson,Sharma,Shojaeiarani,&Bajwa,2018; Heetal.,2018; Mamvura&Danha, 2020; Pradhan,Mahajani,&Arora,2018),andbriquettes(Bajwaetal.,2018; Kaliyan&VanceMorey,2009; Zhang,Sun,&Xu,2018).Inthesestudies,severalbiomassesareanalyzedaswellasdifferentconversionpathways,withthemainobjectiveof obtainingfeasibleprocesseswithhighyields.Nevertheless,biofuelsmustalsobecompetitivefromtheeconomicpointofviewwithitsfossilcounterparts;thisimpliesthatthe productioncostsofbiofuelsmustbeassmallaspossible.Inthiscontext,processintensificationplaysakeyrole,sinceitcouldhelptohavecompactprocess,withreduced energyconsumption,safer,andenvironmentallyfriendly.
Therefore,inthischapterthepotentialadvantagesonusingprocessintensificationin thebiofuelproductionprocesseswillbeexplored.Forthis,itwillbepresentedthegeneralitiesoftheconventionalproductionprocessesforbiofuels,aswellastheconceptof processintensification.Basedontheseconcepts,thenecessityofapplyingprocessintensificationintheproductionprocessesforbiofuelswillbeexposed.Finally,thecurrent stateoftheintensifiedbiofuelproductionprocesseswillbedescribed.
1.2Basicconceptsonprocessintensification
Theproductionprocessescanbedefinedasasuccessionofunitoperations,wheretheraw materialsareadequated,transformed,andpurifiedtoobtaintheproductofinterest;this typeofproductionprocessesareusuallyknownasconventionalones.Mostoftheconventionalequipmenthasasmaintroublesomethepresenceofdeadzones,shortcutsinthe processing,orlimitedheatandmasstransfers;asconsequence,theyareusuallyoversized, whichdirectlyimpactsitsinvestmentandoperationcosts.Inthiscontext,processintensificationarisesinordertoovercometheselimitations.
Processintensificationisdefinedasanychemicalengineeringdevelopmentthatleads toasubstantiallysmaller,cleaner,andmoreenergy-efficienttechnology(Stankiewicz& Moulijn,2000).Theintensificationofaprocessconsiderstwomainstrategies:theuseof highlyefficientequipmentorthecombinationoftwo,ormore,unitoperations.Inthe
firstcase,newequipmenthasbeenproposed,whosemaincharacteristicisthehighrateof heatand/ormasstransfer;asconsequence,itssizeissmallincomparisonwithitsconventionalcounterpart.Inthesecondcase,thethermodynamicsynergyisusedinorderto carryouttwo,ormore,unitoperationsinthesamevessel,whichareusuallycalledas hybridequipment;asconsequence,theinvestmentandoperationcostsarereduced.
Theapplicationofprocessintensificationstrategyhasmanyadvantages.Thefirstone isthatthistypeofprocessareinherentlysafer;sincetheequipmentaresmallerorhybrid, theamountofreactants,solvents,aswellasenergyarelower.Thusincaseofanaccident, thepotentialconsequencescanbemanagedmoreeasily.Thesecondoneisthattheplants aresmaller,respecttotheconventionalones,sincehigherratesofheatand/ormasstransferareobserved;inconsequence,minorareasfortheconstructionoftheplantare required,andinsomecases,lesspipesandadditionalequipment(likepumps).Thethird oneisthattheintensifiedprocessesaremorecompetitivefromtheeconomicpointof view,duetotheefficientuseofenergyandrawmaterials.Finally,theintensifiedprocess hasareducedcarbonfootprintwithoutloseproductivity.Ontheotherhand,process intensificationhastwomaindisadvantages.Themaindisadvantageisthatnotall processintensificationalternativeshaveabetterperformanceinalltypeofprocess,in comparisonwiththeconventionalone;thusthealternativesmustbeevaluated.Theseconddisadvantageisthatprocessintensificationimpliesthereplacementoftheequipment, forasmalleroneorforahybridtechnology.
Untilnow,severaladvanceshavebeenreportedintheliteratureinrelationtothe proposalofintensifiedequipmentforreaction,separation,andconditioningtasks.These alternativeswillbepresentednext.
1.2.1Reactionequipment
Areactorisavesselwhereachemicalreactioniscarriedout.Thereactorscanbeclassified basedonthenumberofphasesinteractingonit.Thehomogeneousreactorsarethose wherethereactants,products,andcatalystsareinthesamephase;ontheotherhand, theheterogeneousreactorsarethosewherethereactants,products,andcatalystsarein atleasttwodifferentphases.Thereactorscanalsobeclassifiedbasedonitsform:tank withagitationandtubular(Fig.1.5).
Inspiteofitsformorthenumberofphasespresent,thesetypesofconventionalreactorspresentdeadzones,shortcuts,anditisnecessarytointroducethereactantsinexcess inordertoobtainhighconversionrates.Inordertoovercometheselimitations,new reactorequipmenthasbeenproposed,amongwhichcanmentionmultifunctionalreactors,microreactors,microchannelreactors,spinningdiskreactor,heatexchangerreactor, oscillatoryflowreactor(Fig.1.6).
Themultifunctionalreactorsallowtocarryonseveralreactionsinthesamevessel, whichfavorsthegenerationofsomeproductsofinterest.Inthistypeofreactor,the
Intensifiedreactors.
intensificationallowsperformingseveralreactionsinthesamevessel;however,thetype ofreactorisconventional.Forinstance,thehydroprocessingofonestepfortheconversionofoilintohydrocarbonsisanexampleofthistypeofmultifunctionalreactor (Gutierrez-Antonioetal.,2017).
Ontheotherhand,theotherequipmentshowedin Fig.1.6 arenewdesigns, wheretheheatandmasstransferareintensifiedinsuchawaythatthesizeoftheequipmentissmall.
Fig.1.5 Conventionalreactors.
Fig.1.6
Microreactorsaredevicesconsistingofsingleormultiplesmall-diameterchannels, typicallybetween10and1000 μm(Moulijn&Stankiewicz,2017).Someofthereactions thathavebeenstudyinmicroreactorsincludehydrogenproductionandethylenepartial oxidation(Keiski,Ojala,Huuhtanen,Kolli,&Leivisk€a,2011).Themaindifference betweenmicroreactorsandmicrochannelreactorsisthesizeofthechannels.Microchannelreactorscanbedefinedasreactorsconsistingofchannelswithahydraulicdiameter (Dh)morethan3mm,whilemini-channelscanbeconsideredasreactorswithchannels withahydraulicdiameterintherangeof200 μm–3mmandmicrochannelswitha hydraulicdiameterintherangeof10–200 μm(Kiani,Makarem,Farsi,&Rahimpour, 2020).Microchannelreactorshavebeenusedfortheconversionofsyngastoalcohols (Reay,Ramshaw,&Harvey,2013a).Theoscillatoryflowreactorssuperimposeanoscillatoryflowtothenetmovementthroughaflowreactor,withtheaimtoeffectivelyhavea plugflow(Bianchi,Williams,&Kappe,2020);thistypeofreactorshasbeenusedforthe conversionofjatrophaoiltobiodiesel(Ghazi,Resul,Yunus,&Yaw,2008).Theheat exchangerreactorallowsthecombinationofthereactionandheatexchange,which increasestheselectivityandpreventrunawayreactions(Hesselgreaves,Law,&Reay, 2017a,2017b);thistypeofequipmenthasbeenusedforthesteamreformingofLPG, ethanol,andmethanolandcatalyticcombustionofLPGandmethanol(Kolbetal., 2007).Finally,thespinningdiskreactorhashighfluiddynamicintensity,which favorstherapidtransmissionofheat,mass,andmomentum(Reay,Ramshaw,& Harvey,2013b),therebymakingitanidealvehicleforperformingfastendothermicreactionssuchascatalyticisomerizationof α-pineneoxidetocampholenicaldehyde(Reay etal.,2013a,2013b).
Theintensifiedreactorsofferhighertransferratesofheatandmass,whichreducedead zonesand,asconsequence,thesizeoftheequipmentdecreases.Animportantfactisthat inthistypeofequipmenttheconversionishigher,andtherunawayreactionsarebetter controlled.
1.2.2Separationequipment
Oncetherawmaterialshavebeentransformedintoproducts,thepurificationofthem mustbemade.Usually,thepurificationimpliestheseparationofunreactedcompounds aswellasbyproductsgenerated.Thereareseveralunitoperationsthatcanbeusedto separatetheproductsofinterest,suchasliquid-liquidextraction,adsorption,absorption, membranes,evaporation,anddistillation;nevertheless,distillationisthemostcommon methodfortheseparationoffluidmixtures.Thusinthissection,thefocuswillbegiven onthisunitoperation.
Distillationisaunitoperationthatallowsthepurificationofhomogeneousmixtures offluids,throughthetransferofmassbetweenliquidandvaporstreams;theselastonesare createdwithareboilerandacondenser,locatedinthebottomandtopofthedistillation
columns,respectively.Aconventionaldistillationcolumncanseparateoneproductatthe time,bytoporbottom;thususuallyatrainofdistillationcolumnsisrequired.Thesedistillationtrainsareconsideredasconventionalones,andthetwomoreknownsequences arethedirect(wherethemostoftheproductsareobtainedatthetopofthecolumn)and theindirect(wherethemostoftheproductsareobtainedatthebottomofthecolumn); theconventionaldistillationtrainsarepresentedin Fig.1.7 forthepurificationofaternarymixture.
Thedistillationcolumnsareveryflexibleintheirdesignfortheseparationofmixtures ofdifferentcharacteristics;theirmaindisadvantageistheirlowthermodynamicefficiency,duetotheremixingeffect.Toovercomethisweakness,newdistillationconfigurationshavebeenproposed,andtheyareknownasthermallycoupleddistillation sequences(Fig.1.8).
Thethermallycoupleddistillationschemesconsistofdistillationcolumnslinked betweenthemthroughliquidandvaporinterconnectionflows.Sincethesupplyofliquid andvaporrequirementsissatisfiedwiththeinterconnectionflows,itispossibletoeliminateacondenserand/orareboiler;thishelpstodecreasetheinvestmentcostforthe separationofthemixture.Moreover,intypeofschemes,itispossibletoreducethe energyrequirementssincetheinterconnectionflowsarelocatedtoavoidtheremixed effect.Accordingtotheliterature,thermallycoupleddistillationsequencescanreduce theenergyrequirementsbetween30%and50%,incomparisonwithconventionaldistillationsequences(Caballero,2009; Dejanovic,Matijasˇevic,&Olujic,2010; Go ´ mezCastroetal.,2016; Yildirim,Kiss,&Kenig,2011).Thereareseveraltypesofthermally coupleddistillationsequencessuchasthedirectandindirectones,aswellasthePetlyuk
Fig.1.7 Conventionaldistillationsequences.
distillationcolumnandthedividingwalldistillationcolumn.Inparticular,thedividing walldistillationcolumnisaverypromisingtechnologyallowingasignificantenergy requirementreduction(Yildirimetal.,2011),aswellasreductioninspacerequirements andpipingandinstallationcosts.
Moreover,thermallycoupleddistillationcolumnshavebeenusedfortheseparation ofmulticomponentmixtures(Avendano,Pinzo ´ n,&Orjuela,2020; Kiss,Ignat,Flores Landaeta,&deHaan,2013; Rong,2011; Vazquez-Castilloetal.,2009),azeotropic (Waltermann,M € unchrath,&Skiborowski,2017; Yangetal.,2019; Zhangetal., 2020),extractivemixtures(Aniya,De,Singh,&Satyavathi,2018; Murrieta-Duen ˜ as, Gutierrez-Guerra,Segovia-Herna ´ ndez,&Herna ´ ndez,2011; Staak&Gr€ utzner,2017; Yangetal.,2020)aswellasreactiveprocesses(Murrieta-Duenasetal.,2011; Weinfeld,Owens,&Eldridge,2018).
1.2.3Conditioningequipment
Inallconversionprocess,reactionandpurificationzones,aswellastheconditioning equipment,areessentials.Usually,theconditioningequipmentisusedtomodifythe temperature,pressure,orsizeoftherawmaterials;thusinthiscategoryofequipment, heatexchangers,pumps,compressors,turbines,grinders,andcrusherscanbefound (Fig.1.9).Amongtheseequipment,thedesignofheatexchangershasbeenstudied
Fig.1.8 Thermallycoupleddistillationsequences.
Fig.1.9 Conventionalconditioningequipment.
Fig.1.10 Intensifiedconditioningequipment.
andimprovedthroughdifferentstrategies(Awais&Bhuiyan,2018; Dixit&Ghosh, 2015; Klemes ˇ etal.,2020).
Thetraditionalheatexchangersemployconventionaltubes( 6mm)withvarious cross-sectionsandorientations;eveninthosewithenhancedsurfacetextures,thistechnologyisnearingitslimits(Khan&Fartaj,2011).Incontrast,intensifiedequipmentfor heatexchangerisofsmallersizerespecttoconventionaltechnology(Fig.1.10).
Microchannelheatexchangers( 1mm)representanimprovedalternativedueto theirhigherheattransferandreducedbothweightandspacerequirements(Khan& Fartaj,2011).Therearealsominichannelheatexchangerswithdiametersgreaterthan 200 μmbutminorsorequalthan3mm(Dhar,2017).Othertypeofintensifiedequipmentisthecompactheatexchanger,whichisformedoflayersofplatesorfinnedchannels offixedlengthandwidth(Hesselgreavesetal.,2017a,2017b);amongthiskindofheat exchangers,thefollowingareincluded:theplateheatexchangers,theprintedcircuit heatexchanger,theChart-flowunitofchartheatexchangers,andthepolymerfilmheat exchanger(Reay,Ramshaw,&Harvey,2008).
1.2.4Designmethodologiesforintensifiedequipment
Thedesignofintensifiedequipmentcanbeaddressedwiththreedifferentapproaches: shortcutmethodologies,optimizationstrategies,andtheuseofcomputationalfluid dynamics.Shortcutmethodologiesaredefinedasdesignproceduresthatemploymainly materialbalancesandsimpleequationsforthemodelingofthethermodynamicbehavior ofthecomponentsinvolved.Forinstance,inthedesignofidealconventionalreactors, massbalancealongwiththekineticmodelisemployed(Smith,1981),whileinconventionaldistillationsequences,theFensk-Underwood-Gillilandequationsareused (Henley&Seader,1981).Ontheotherhand,optimizationprocedurescanbeusedas adesigntool;usuallytheobjectivesconsideredaretheyield,energyconsumption,or volume.Theoptimizationprocedurescanincludemathematicalprogrammingaswell asmetaheuristicstrategies,andevencanbelinkedtoprocesssimulators(Modak, Lobos,Merigo ´ ,Gabrys,&Lee,2020; Pistikopoulosetal.,2021).Finally,computational fluiddynamicsisanefficientcomputerizedmethodofstudyingfluidmechanicsbasedon numericalanalysis( Junka,Daly,&Yu,2013).Thuscomputationalfluiddynamicsisa powerfultoolforthesimulationanddesignofintensifiedequipment,especiallythose whichareminiaturized.
Regardthedesignofintensifiedequipmentforchemicalreactions,optimizationproceduresaswellascomputationalfluiddynamicsarethemostcommontools.According totheliterature,optimizationprocedureshavebeenappliedtoobtaintheoptimaldesign oftailor-madereactors(Freund,Maußner,Kaiser,&Xie,2019),amultitubularreactor forethyleneproduction(Ovchinnikova,Banzaraktsaeva,&Chumachenko,2019),and capillary-basedLSC-photomicroreactors(Zhaoetal.,2020).Ontheotherhand,computationalfluiddynamicsmethodologieshavebeenusedtodesignamicrochannelreactorheat exchanger(Engelbrecht,Everson,Bessarabov,&Kolb,2020),gas-solidvortexreactorfor oxidativecouplingofmethane(Vandewalle,Marin,&VanGeem,2021),photocatalytic reactorsinthegasphase(OliveiradeBritoLira,Riella,Padoin,&Soares,2021),microwave heatinginheterogeneouscatalysis(Yan,Stankiewicz,EghbalSarabi,&Nigar,2021),aswell aspneumaticallyagitatedslurryreactors(Geng,Mao,Huang,&Yang,2021).
Thedesignofintensifieddistillationschemescanbemadewithshortcutmethodsaswell asoptimizationprocedures.Amongtheshortcutmethodologies,thosecanbecitedarethe onesproposedforthedesignofthermallycoupleddistillation(Herna ´ ndez&Jimenez, 1996),thesynthesisofintensifiednonsharpdistillationsystems(Rong,2014),andsimple columnconfigurationsformulticomponentdistillation(Rong&Errico,2012).Onthe otherhand,thegenerationofoptimaldesignsthroughoptimizationstrategiesisreported throughtheuseofmulticomponentintensifieddistillationsystems(Errico,Pirellas, Torres-Ortega,Rong,&Segovia-Hernandez,2014),intensifiednonsharpdistillationconfigurations(Torres-Ortega,Strieker,Errico,&Rong,2015),intensifiedthermallycoupled distillationsequences(Caballero&Reyes-Labarta,2016),synthesisofintensifiedsequences formulticomponentzeotropicmixtures(Li,Demirel,&Hasan,2019),dividingwallcolumnsforextractiveseparations(Lietal.,2021),separatingnormalalkanesviamultiobjectiveoptimization(Liu,Ren,etal.,2021; Liu,Wei,&Leng,2021).Forthedesign ofreactivedistillation,thereareshortcutmethodologiesaswellasoptimizationstrategies. Regardtheshortcutmethodologies,theworksof BarbosaandDoherty(1988), Dragomir andJobson(2004), Carrera-Rodrı´guez,Segovia-Herna ´ ndez,andBonilla-Petriciolet (2011), Flores-EstrellaandIglesias-Silva(2016) canbecited.Inaddition,optimizationstrategieshavebeendevelopedfortheoptimaldesignofreactivedistillation,asitcanbeseenin theworksof CiricandGumus(2009), Tsatse,Oudenhoven,tenKate,andSorensen(2021), and Tian,Pappas,Burnak,Katz,andPistikopoulos(2021)
Regardtheintensifiedheatexchangers,mostofthereportedworksareexperimental; thestudiesonthedesignofintensifiedheatexchangersarescarce,andtheyemployed computationalfluiddynamicsasdesigntool(Alimoradi,Olfati,&Maghareh,2017; Bahiraei,Mazaheri,&Hanooni,2021; Jamshidmofid,Abbassi,&Bahiraei,2021; Piriyarungrodetal.,2018).
1.3Conventionalprocessesfortheproductionofbiofuels
Asitwasmentionedbefore,thebiomasscanbeconvertedintobiofuelsinliquid,gaseous orsolidstate.Inthissection,thedefinition,mainuses,aswellastheconventionalprocess foritsproductionwillbepresented.
1.3.1Liquidbiofuels
Amongliquidbiofuels,wecanmentionbioethanol,biobutanol,biogasoline,biodiesel, greendiesel,andrenewableaviationfuel.
Bioethanol,aswellasbiobutanol,isanalcohol,whosechemicalcompositionis exactlythesameofitsfossilcounterpart;themaindifferenceisthatbioethanolandbiobutanolarenotgeneratedfrompetroleum(Alam&Tanveer,2020).Bioethanolcanbe usedasanadditiveininternalcombustionenginesthatoperatewithgasolineorasafuelin enginesspecificallydesignedforit.Inaddition,bioethanolcanbeusedinthebeverage
Fig.1.11 Mainstepsintheconventionalprocessfortheproductionofbioethanol.
industryaswellasrawmaterialforthegenerationofethyleneandderivativecompounds (Ferreira,Agnihotri,&Taherzadeh,2019).Ontheotherhand,biobutanolhascaptured theattentionforitspotentialuseasgasolinereplacement(Roberts&Patterson,2014). Biobutanolcanbeusedasanadditiveininternalcombustionenginesthatoperateswith gasoline,until12.5%volumeaccordingtothestandardASTMD7862-19(ASTM, 2019).Inaddition,biobutanolisusedasasolventincosmetics,hydraulicfluids,detergent formulations,drugs,antibiotics,hormones,andvitamins,asanintermediateinchemical synthesis,andalsoasanextractantinthemanufacturingofpharmaceuticals(Isom€aki, Pitk€aaho,Niemist € o,&Keiski,2017).
Bioethanolandbiobutanolcanbeproducedthroughfermentationofsugars,which canbeobtainedforcultivatedorresidualbiomass. Fig.1.11 showsthemainprocessinthe productionofbioethanol.
Asitcanbeseenin Fig.1.11,bioethanolcanbeproducedfromlignocellulosic,sugar, andstarchfeedstock.Inallcases,itisnecessarytogrindthefeedstockinordertoincrease theavailableareaforthereleaseofthesugarscontainedintherawmaterial.Inthecaseof sugarfeedstock,itisusuallyrequiredtoperformasolid–liquidextraction,whilehydrolysisisusedforstarchfeedstock;inthecaseoflignocellulosicfeedstock,pretreatmentsare carriedontoseparatecelluloseandhemicellulosefrombiomassfollowedbyhydrolysis andsaccharification.Later,thereleasedsugarsarefermentedusuallywith Saccharomyses cerevisiae inordertogeneratebioethanol(Ciani,Comitini,&Mannazzu,2008).Typical yieldstobioethanolareintheorderof5%–12%,sinceatmajorconcentrationsthemicroorganismsareinactivated(Dimian,Bildea,&Kiss,2014).Duetothis,theseparationis necessaryinordertoobtainanhydrousbioethanol.Typically,distillationhasbeenused forthepurificationofbioethanol,forwhichtheazeotropicpointmustbeoverpass;this usuallyrequirestheuseofasolvent,suchasethyleneglycol(Pacheco-Basultoetal., 2012).Intheconventionalprocessfortheproductionofbioethanol,itspurificationis theoperationwithhigher-energyconsumption.
Ontheotherhand,themainstepsinvolvedintheproductionprocessofbiobutanol areshownin Fig.1.12.
From Fig.1.12,itisimportanttomentionthatthepretreatmentandhydrolysissteps areexactlythesamepreviouslydescribedforbioethanolproduction.Themaindifference reliesonthefermentationanddistillationsteps.Thereleasedsugarsareconverted
feedstock
throughacetone-butanol-ethanol(ABE)fermentation,whosenameindicatesthatthese productsaregenerated.Theconcentrationsofbutanolrangefrom2.75to12g/L, obtainedwith Clostridiumacetobutylicum ATCC824(Sindhuetal.,2019).Duetothe lowyields,theseparationisnecessaryinordertoobtainbiobutanol;accordingtotheliterature,distillationandliquid-liquidextractionhavebeenusedforthepurificationofthe productsofABEfermentation(Kaymak,2018; Sa ´ nchez-Ramı´rez,Quiroz-Ramı´rez, Segovia-Herna ´ ndez,Herna ´ ndez,&Ponce-Ortega,2016).Intheconventionalprocess fortheproductionofbiobutanol,itspurificationistheoperationwithhigher-energy consumption.
Ontheotherhand,renewablegasolineorbiogasolineconsistsofhydrocarbonsinthe rangeofC4–C12,generatedfrombiomass;inastrictsense,biogasolinewouldexclude thealcoholssincealcoholsaretypicallyoxygenated,incontrastwithoil-derivedfuels (Pagliuso,2010).Thusthecompositionofbiogasolineandgasolinearethesame,aswell asitsproperties(ASTM,2021).Thusthebiogasolinecanbeusedinmixtureswithfossil gasolineorat100%ininternalcombustionenginesthatoperatewithfossilgasoline.In addition,biogasolinecanbeusedtoproducesteaminboilers,ortogenerateelectricityin smallpowerplants. Fig.1.13 showstheroutestoproducebiogasoline.
Asitcanbeobservedfrom Fig.1.13,biogasolinecanbeproducedfromtriglyceride, lignocellulosic,sugar,andstarchfeedstocktodifferentprocessingpathways.Iftriglyceridefeedstockisused,itmustbehydroprocessedinordertogeneratebiogasoline,aswell aslightgasesanddieselfuel;inaddition,biooilderivedfromthepyrolysisoflignocellulosicfeedstockcanalsobehydroprocessedtogeneraterenewablegasoline.Ontheother hand,itispossibletoproducebiogasolinefromsugarandstarchfeedstock,throughits conversiontoalcoholandlateroligomerizated.Inspiteofthetypeofrawmaterialused, distillationisincludedforthepurificationofthehydrocarbonsgenerated.Thereported selectivitiesforrenewablegasolineare90%orhigher(Duanetal.,2020; OhayonDahan, Porgador,Landau,&Herskowitz,2020).Intheseconversionpathways,thepyrolysis, hydrodeoxygenation,aswellasdistillationarethemostenergy-intensiveprocesses.
Bioethanolandbiobutanolhavebeenproposedasreplacementsoradditivesforgasoline,whilebiodieselandgreendieselhavebeendevelopedforfossildiesel.Inparticular, biodieselisamixtureoflongchainfattyacidestersthataregeneratedthroughatransesterificationreaction(Du,Kamal,&Zhao,2019);biodieseldiffersfromfossildieselin composition,sincethelastoneconsistsofhydrocarbonsintherangeofC17–C28.
Starch feedstock Sugar feedstock
Acetone Biobutanol Bioethanol
Lignocellulosic feedstock Pretreatment HydrolysisFermentationDistillation
Fig.1.12 Mainstepsintheconventionalprocessforbiobutanolproduction.
Biodieselcanbeusedinmixturesininternalcombustionenginesthatoperatewithfossil dieselorat100%inenginesspecificallydesignedforthisbiofuel(ASTM,2020a).Inaddition,itcanbeusedasfuelinboilerstogeneratesteamorinsmall-generationpower plants. Fig.1.14 showsthemainstepsintheconventionalprocessfortheproduction ofbiodiesel.
Biodieselcanbeproducedfromtriglyceridefeedstock,whichmayrequireapretreatmentespeciallyiftherawmaterialisresidual.Thetriglyceridesareconvertedintofatty acidestersandglycerol,throughtransesterificationandesterificationreactions;these productsmustbeseparatedbydecantation.Finally,thebiodieselispurifiedtoeliminate theimpuritiesandreachthepurityrequiredforitsuseasfuel.Themostusedprocess involvesthehomogeneouscatalysis,whichcanbeacidorbasic;theconversionsare 98%orgreater(BritoCruz,Souza,&BarbosaCortez,2014).Intheconventionalprocess
Fig.1.13 Mainstepsintheconventionalprocessforbiogasolineproduction.
Fig.1.14 Mainstepsintheconventionalprocessforbiodieselproduction.
Fig.1.15 Mainstepsintheconventionalprocessesforgreendieselproduction.
fortheproductionofbiodiesel,itspurificationistheoperationwithhigher-energyconsumptionandalsowiththegreaterhydricfootprint.
Ontheotherhand,greendieselconsistsofhydrocarbonsintherangeofC17–C28, whichcorrespondtothesamecompositionoffossildiesel.Greendieselcanbeusedin mixturesininternalcombustionenginesthatoperatewithfossildieselorat100%in enginesdesignedtooperatewithfossildiesel(ASTM,2020a).Moreover,greendiesel canbeusedasfuelinboilerstogeneratesteamorinsmallgenerationpowerplants.
Fig.1.15 showsthemainstepsintheconventionalprocessfortheproductionofgreen diesel.Similartotheproductionofbiogasoline,greendieselcanbegeneratedfromsugar, starch,triglyceride,orlignocellulosicfeedstockfordifferentconversionpathways;in spiteoftheprocessingpathway,thepurificationofthegeneratedhydrocarbonsiscarried outthroughdistillation.Thereportedselectivitiesfortheproductionofgreendiesel rangefrom80%to94%(Ameenetal.,2020; Papanikolaouetal.,2020).Inthese
