WASTEANDBIODIESEL
FeedstocksandPrecursors forCatalysts
Editedby BHASKARSINGH
DepartmentofEnvironmentalSciences,CentralUniversityof Jharkhand,Ranchi,India
ABHISHEKGULDHE
AmityInstituteofBiotechnology,AmityUniversityMaharashtra, Mumbai,India
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Foreword
Therecentlyheldclimateconference(COP26)atGlasgow,andthepledgestaken bymostparticipatingcountriestoshift100%torenewablesassoonaspossible,hasonce againhighlightedtheimportanceofrenewablefuels,especiallybiodiesel.Averyattractive featureofbiodieselisthatits“neat”form(B100)canbeblendedtotheextentofupto 20%withmineraldieselandtheblendcanbeusedtorunexistingengineswithlittleor nomodifications.
Butthereareseveralchallengesassociatedwiththelarge-scaledeploymentof biodiesel.Therawmaterialsneededforit—vegetableoilsandanimalfats—notonly havestronglycompetitiveusesasfood,feed,andindustrialrawmaterialsbutalsoneed largeareasofarablelandandlargevolumesofirrigationqualitywaterwhichbothare becomingincreasinglyprecious.Thesefactorsmakebiodieselprohibitivelycostlyaswell.
TogetroundthesehurdlesstrongR&Dthrustsarebeingmadeacrosstheworldto utilizewastematerialsasfeedstocksinbiodieselgeneration.Thepresentbookistheresult ofthecompilation,collation,andsynthesesofallexistingknowledgeinthisexceedingly importantareaofenergytechnology.Inthefirstfivechapterstheentiregamutofbiodiesel productionfromdifferentformsofwastehasbeencovered,encompassingwasteanimal fats,municipalwastelipids,microalgae,fungi,bacteria,andyeast.Inthenextfourchapters, therolesofallpossiblewaste-derivedcatalystshavebeendocumentedinspeedingupand enhancingofbiodieselgeneration.Thepenultimatechapterexpressesthestate-of-the-art oftheintegrationoffluegasbiomitigationwithbiodieselproduction.Theconcluding chapteraddressesthecrucial,butrarelycovered,aspectoftheenvironmentalimpacts associatedwithbiodieselandthelegallimitsprescribedinthatcontext.
TheeditorsDr.BhaskarSinghandDr.AbhishekGuldhehavebothhadahighly meritoriousresearchcareer,distinguishedbytheircopiousoutputofsustainedexcellence. Withcloseto10,000citationsbetweenthem,thewriterduoisnowamongtheforemost scientistsinthisfield.Theirwealthofexpertiseisreflectedinthemeticulousplanning ofthebook,selectionofthemostappropriateofthecontributions,andensuringthatall chaptersmeetthehigheststandardsofcomprehensiveness,cogency,andclarity.
Iamsurethisbookwillblazeatrial.KudostoElsevierforundertakingthisprojectat therighttimeandtotheauthorfortheirimpeccabletranscreationoftheconceptinto reality.
S.A.Abbasi INSAEmeritusProfessor PondicherryUniversity India https://vidwan.inflibnet.ac.in/profile/61966
Preface
Biodieselhasemergedasapromisingalternativerenewablefuel.Severalfeedstocks andprocessingtechniqueshavebeenstudiedanddevelopedbyresearchersacrossthe globe.Despitethesustainabilityandenvironmentalbenefitsattributedtobiodiesel,ahigh productioncostisthemajorbottleneckforcommercializationofbiodiesel.Themajor contributorstowardstheproductioncostarefeedstockprocurement,oilextractionand oiltobiodieselconversionprocess.Researchersandpolicymakersofnationsworldwide haverecentlyadvocatedtowardsincorporatewastematerialsinthebiodieselproduction processtoreducetheproductioncost.Wastematerialscanbeusedasfeedstockorin otherprocessingstepssuchassynthesisofcatalystsforconversionofoiltobiodiesel.In otherapproach,wastematerialcanbeusedasresourcetodeveloppotentialfeedstock orcatalysts.Thisbook,WasteandBiodiesel:FeedstocksandPrecursorsforCatalystsaim tocriticallyevaluatetheemergingtrendsofutilizingwasteinvariousstagesofbiodiesel productionprocess.
Chaptersinthebookincludeoverviewofwasteutilizationinbiodieselproduction process,criticalevaluationofwasteanimalfats,municipalwastederivedlipidsand biowastesasbiodieselfeedstock,biodieselproductionfrommicroalgae,oleaginousfungi, yeastandbacteriabiomassproducedbyusingwastesubstratesasnutrientmedium. Chaptersalsoincluderecenttrendsandadvancementsinsynthesizingcatalystsusedfor biodieselproductionfromwastederivedfromorganicorigin,suchaswasteshell,fishand animalwaste,andinorganicmaterials.Achapterdealswithwholecellenzymecatalyst forproductionofbiodiesel.Achapteralsodiscussesintegrationoffluegasmitigation inbiodieselproductionprocess.Integrationofwasteinbiodieselproductionprocess provideseconomicalaswellasenvironmentalbenefitsandleadstowardsthesustainable productionofbiodiesel.
BhaskarSingh AbhishekGuldhe
Contributors
MaiO.Abdelmigeed
ChemicalEngineeringDepartment,CairoUniversity,Giza,Egypt
OmarM.Abdeldayem
EnvironmentalEngineeringProgram,ZewailCityofScienceandTechnology,Giza,Egypt
WiuryC.Abreu
FederalInstituteofMaranhão,Buriticupu,MA,Brazil
AdewaleAdewuyi
DepartmentofChemicalSciences,FacultyofNaturalSciences,Redeemer’sUniversity,EDE, OsunState,Nigeria
ShahrukhN.Alam
DepartmentofEnvironmentalSciences,CentralUniversityofJharkhand,Ranchi,India
T.CAniokete
DepartmentofChemicalEngineering,FacultyofEngineering,EnuguStateUniversityof ScienceandTechnology,Enugu,Nigeria
NaveenK.Arora
DepartmentofEnvironmentalSciences,BabashahebBhimraoAmbedkarUniversity,Lucknow, India
EslamG.Al-Sakkari
ChemicalEngineeringDepartment,CairoUniversity,Giza,Egypt
RifatAzam
DepartmentofEnvironmentalSciences,BabashahebBhimraoAmbedkarUniversity,Lucknow, India
RachaelJBarla
DepartmentofChemicalEngineering,BirlaInstituteofTechnologyandScience(BITS)Pilani, Rajasthan,India
DeovratN.Begde
DepartmentofBiochemistry&Biotechnology,Dr.AmbedkarCollege,Deekshabhoomi, Nagpur,Maharashtra,India
DariaC.Boffito
ChemicalEngineeringDepartment,PolytechniqueMontreal,Montreal,Canada
JeanC.S.Costa
FederalUniversityofPiaui,Teresina,PI,Brazil
M.O.Daramola
DepartmentofChemicalEngineering,FacultyofEngineering,BuiltEnvironmentand InformationTechnology,UniversityofPretoria,Pretoria,SouthAfrica
SumitH.Dhawane
DepartmentofChemicalEngineering,MaulanaAzadNationalInstituteofTechnology,Bhopal, India
AlaaeldinA.Elozeiri
EnvironmentalEngineeringProgram,ZewailCityofScienceandTechnology,Giza,Egypt
AyodejiJFatehinse
DepartmentofChemicalSciences,FacultyofNaturalSciences,Redeemer’sUniversity,EDE, OsunState,Nigeria
KajolGoria
DepartmentofEnvironmentalSciences,CentralUniversityofJammu,Jammu,Jammuand Kashmir,India
AbhishekGuldhe
AmityInstituteofBiotechnology,AmityUniversityMaharashtra,Mumbai,India
SureshGupta
DepartmentofChemicalEngineering,BirlaInstituteofTechnologyandScience(BITS)Pilani, Rajasthan,India
ZairaKhalid
DepartmentofEnvironmentalSciences,CentralUniversityofJharkhand,Ranchi,India
RichaKothari
DepartmentofEnvironmentalSciences,CentralUniversityofJammu,Jammu,Jammuand Kashmir,India
BlazLikozar
DepartmentofCatalysisandChemicalReactionEngineering,NationalInstituteofChemistry, Ljubljana,Slovenia
KhushalMehta
DepartmentofBiology,SRMUniversity-AP,AndhraPradesh,India
CarlaV.R.Moura
FederalUniversityofPiaui,Teresina,PI,Brazil
EdmilsonM.Moura
FederalUniversityofPiaui,Teresina,PI,Brazil
MarwaM.Naeem
ChemicalEngineeringDepartment,BritishUniversityinEgypt,Cairo,Egypt
MahmoudNasr
EnvironmentalEngineeringDepartment,Egypt-JapanUniversityofScienceandTechnology (E-JUST),P.O.Box179,NewBorgEl-ArabCity,Alexandria21934,Egypt;Sanitary EngineeringDepartment,FacultyofEngineering,AlexandriaUniversity,P.O.Box21544, Alexandria21526,Egypt
ImranPancha DepartmentofBiology,SRMUniversity-AP,AndhraPradesh,India
SmitaRaghuvanshi
DepartmentofChemicalEngineering,BirlaInstituteofTechnologyandScience(BITS)Pilani, Rajasthan,India
ShubhamRaina
DepartmentofEnvironmentalSciences,CentralUniversityofJammu,Jammu,Jammuand Kashmir,India
O.OSadare
DepartmentofChemicalEngineering,FacultyofEngineering,BuiltEnvironmentand InformationTechnology,UniversityofPretoria,Pretoria,SouthAfrica
AnjaliSingh InstituteofMicrobiology,AlgatechCentrum,CzechAcademyofScience,Trebon,Czech Republic
BhaskarSingh
DepartmentofEnvironmentalSciences,CentralUniversityofJharkhand,Ranchi,India
HarMohanSingh
SchoolofEnergyManagement,ShriMataVaishnoDeviUniversity,Jammu,Jammuand Kashmir,India
PoonamSingh
InstituteofPlantMolecularBiology,BiologyCentre,CzechAcademyofScience,Czech Republic
KiranToppo
CSIR-NationalBotanicalResearchInstitute,Lucknow,UttarPradesh,India
V.V.Tyagi
SchoolofEnergyManagement,ShriMataVaishnoDeviUniversity,Jammu,Jammuand Kashmir,India
Contributors ix
Foreword xiii
Preface xv
Acknowledgments xvii
1.Biodieselandanoverviewofwasteutilizationatthevariousproductionstages1 ShahrukhN.Alam,ZairaKhalid,AbhishekGuldheandBhaskarSingh
1.1 Introduction 1
1.2 Biodieselproductionprocess2
1.3 Integrationofwasteintobiodieselproductionprocess3
1.4 Wastematerialasfeedstock4
1.5 Feedstocksgeneratedusingwastematerial9
1.6 Challengesandfutureprospects11
References 11
2.Prospectsofbiodieselproductionfromwasteanimalfats17 T.CAniokete,O.OSadareandM.O.Daramola
2.1 Introduction17
2.2 Biodieselproductionfromwasteanimalfats21
2.3 Transesterificationofwasteanimalfattobiodiesel32
2.4 Technoeconomicfeasibilityofbiodieselproductionfromwasteanimalfats38
2.5 Challenges/recentstudiesforlarge-scaleproductionofbiodieselfromwasteanimal fatsviatransesterification38
Conclusionsandoutlook39
References 40
3.Efficacyofmunicipalwastederivedlipidsinproductionofbiodiesel45 MahmoudNasr
3.1 Introduction45
3.2 Overviewoflipids/biodieselproductionfrommunicipalsolidwastereportedinliterature47
3.3 Typesofmunicipalsolidwasteavailableforbiodieselproduction51
3.4 Waste-to-energyconversiontechniques54
Conclusions 55
Acknowledgements55 References 55 v
4.Wastewatergrownmicroalgaefeedstockforbiodieselproduction59
PoonamSingh,ImranPancha,AnjaliSingh,KhushalMehtaandKiranToppo
4.1 Introduction59
4.2 Assimilationmechanismofnutrientsbymicroalgae60
4.3 Feasibilityandpotentialofwastewaterbasedmicroalgalcultivation61
4.4 Challengesforbiodieselproduction63
4.5 Biorefineryapproachforbiodieselproductionfromwastewatergrownmicroalgae66
69
5.Biodieselfromoleaginousfungi,bacteria,andyeastproducedusingwaste substrates73
HarMohanSingh,KajolGoria,ShubhamRaina,RifatAzam,RichaKothari, NaveenK.AroraandV.V.Tyagi
5.1 Introduction73
5.2 Oleaginousmicroorganisms74
5.3 Technologiesinvolvedinbiodiesel80
5.4 Challengesandperspectives83
6.CaOderivedfromwasteshellmaterialsascatalystsinsynthesisofbiodiesel91
CarlaV.R.Moura,WiuryC.Abreu,EdmilsonM.MouraandJeanC.S.Costa
6.1 Introduction91
6.2 CaOderivedfromplantresidues92
6.3 CaOderivedfromanimalwaste102
6.4 CaOderivedfrommineralwaste106 Conclusion 113
7.Fishandanimalwasteascatalystsforbiodieselsynthesis119
EslamG.Al-Sakkari,AlaaeldinA.Elozeiri,OmarM.Abdeldayem,BlazLikozar andDariaC.Bofitto
7.1 Introduction119
7.2 Sourcesoffishandanimalwaste-basedcatalyst120
7.3 Preparationoffishandanimalwaste-basedcatalyst121
7.4 Transesterificationkineticsoverwaste-derivedheterogeneouscatalysts124
7.5 Currentstatusoffishandanimalwaste-basedcatalyst126
7.6 Remarksonprocessfeasibilityandgreenness130
7.7 Scaling-up:opportunitiesandlimitations131
8.Inorganicwastesasheterogeneouscatalystsforbiodieselproduction137
EslamG.Al-Sakkari,MaiO.Abdelmigeed,MarwaM.NaeemandSumitH.Dhawane
8.1 Introduction137
8.2 Inorganicwastes144
Conclusionsandfutureperspectives156
References 156
9.Wholecellenzymecatalystproductionusingwastesubstrateforapplication inproductionofbiodiesel163
DeovratN.Begde
9.1 Introduction163
9.2 Transesterification-conventionalandemergentstrategies164
9.3 Whole-cellbiocatalysts-advantagesandlimitations165
9.4 Organismsaswhole-cellbiocatalyst167
9.5 Industrialwasteaspotentialfeedstock/nutrientmediumforwhole-cellenzyme catalystsproduction172
9.6 Otherpotentialsourcesforwhole-cellbiocatalystproduction177
9.7 Stabilizationandoptimizationofwhole-cellbiocatalystforbiodieselproduction177
9.8 Geneticandmetabolicengineeringofwhole-cellbiocatalystforbiodieselproduction178
Concludingremarksandfutureprospects179
References 180
10.Processintegrationforthebiodieselproductionfrombiomitigation offluegases191
RachaelJBarla,SmitaRaghuvanshiandSureshGupta
10.1 Introduction191
10.2 Fluegasmitigationbymicrobialspecies193
10.3 Processintensificationstudyforbiodieselproduction200 Conclusionandfutureprospects209
References 209
11.Bio-wasteasanalternativefeedstockforbiodieselproduction:Currentstatus andlegalenvironmentalimpacts215
AdewaleAdewuyiandAyodejiJFatehinse
11.1 Introduction215
Reference 241 Index 247
Biodieselandanoverviewofwaste utilizationatthevariousproduction stages
ShahrukhN.Alam a,ZairaKhalid a,AbhishekGuldhe b andBhaskarSingh a
a DepartmentofEnvironmentalSciences,CentralUniversityofJharkhand,Ranchi,India
b AmityInstituteofBiotechnology,AmityUniversityMaharashtra,Mumbai,India
1.1Introduction
Fossilfuelreservesthroughouttheworldaredecliningatanexponentialratemainly attributedtopopulationexplosion.Aboveall,theextensiveburningoffossilfuelsfor transportation,energy,industrialapplicationcreatesnegativeenvironmentalissues,such asglobalwarming,continuousCO2 emission,andgreenhousegasemission.Global energyconsumptionhasalreadydoubledbetween1971and2001anditisestimatedthat energydemandby2030istobecalledforadditionalincreaseby53%.Since,thefossil fuelsarenonrenewableandasperBritishPetroleum’s(BP)annualreport,2013itwillget exhaustedinaround50yearsifthecurrentpacecontinues.Consequently,sustainable fuelalternativesarebecomingahighpriorityformanycountriesandareboundto playamajorroleinthefuelindustryintheimmediatefuture.Liquidbiofuelsarebeing advocatedasoneofthemostsustainablealternativestodealwithever-increasingdemand andtotackleenvironmentalconcerns,includingdiminishingfossilfuelreservesand globalwarming.Biodieselhasbeenidentifiedasoneofthebestalternativenonpetroleum basedsustainablefuelconsistingofalkylestersderivedfromeitherthetheesterificationof freefattyacids(FFAs)ortransesterificationoftriglycerides(TGs)orwithshort-chained alcohols.Productionofbiodieselfrombiologicalrenewablesources,suchasvegetableoils, animalfats,wasteoilsandrecentlylignocellulosicmaterialsarebeingreviewedwidely. Manyadvantagesofbiodieseloverconventionalpetroleumdieselare:ithaslowemissions andhencesafer,renewable,biodegradable,betterlubricity,nontoxic,itcontainsnosulfur andbiodegradable.Biodieselistheonlyalternativefueltocompletethehealtheffects testrequirementsoftheCleanAirActAmendments1990.Currently,itisnotamongthe popularalternativefuelgloballymainlybecauseofitshighercostwhencomparedwith conventionalpetroleumdiesel.Themajorprobleminthewidespreadcommercialization ofbiodieselistheavailabilityofthefeedstock,whichmakesthecostofproductionabit high,therebyraisingtheoverallprice.However,therecentadvancementsinusingthe
Figure1.1 Transesterificationreversiblereaction.
cheaprawmaterialinsteadofpricyrefinedvegetableoilandfatisshowingpromising resultsinmakingbiodieselmoreeconomical.
Thischapteraddressesanoverviewofutilizationofvariouswastematerials,suchas wastecookingoil,wasteanimalfats,agriculturalwastes,wastecoffeegrounds,etc.,and thechallengesandotherprospectsofusingthesewastesmaterial.
1.2Biodieselproductionprocess
Thedirectuseofanykindofvegetableoilorfatoritsblendforthepurposeof runninganenginehasbeendeemedimpractical,mainlyduetoitscharacteristicslike highviscosity,freefattyacidcontentandacidcompositionofsuchoils.Thesetypes ofoilsandfatsalsohavetheproblemofgumformationbecauseofpolymerization andoxidationwhilestoringandcombusting.Additionally,thickeningofunprocessed oilwithtimeanddepositionofcarbonaretwomoreissueswhichmakeitunfitfor directapplication(Fukudaetal.,2001).Keepinginview,theproblemsmentionedthe oilsandfatsneedstoundergoconversionprocessestomakeorconvertthemintoviable biodieselformsuitableforconventionaldieselengine.Transesterificationofvegetable oilsorfatswithalcohol(withonetoeightcarbonatoms)isthemostwidelyadapted andpreferredmethodforbiodieselproduction.Basically,therearetwotransesterification methods,oneisperformedwithcatalystandtheotherisperformedanywithoutcatalyst. Theutilizationandselectionoftypeofcatalystisdependedontypeofthefeedstock. Generallytheuseofcatalystsimprovestherateandyieldofbiodieselandispreferred overtheotherdependingonthefeedstockbeingusedforproducingbiodiesel.According to Otera(1993) transesterificationreactioncanbedefinedbythreereversiblereactions whereexcessalcoholshiftsthewholeequilibriumtotheproductsideasdepictedin Fig.1.1.
Firststepinvolvesthereversiblereactionofchangingoftriglyceridestodiglycerides, thenthesecondreactionischangingofdiglyceridestomonoglycerides,similarlyfollowedbyconversionofmonoglyceridestoglycerol.Allthereactionsyieldonemolecule ofmethylesterpermoleofglycerideateverystep(Noureddinietal.,1998).Sometimes,
Figure1.2 Transesterificationprocessdepictingmethanolysisoftriglyceride.
esterificationpriortothetransesterificationprocessisthemostcommonmethodfor reducingthefeedstock’sfreefattyacid(FFA)content.
Thecompletereactioninvolvedintransesterificationprocessis:
Asdepictedin Fig.1.2,R1,R2,andR3arelongchainsofhydrocarbonsandcarbon atomscalledfattyacidchains,whichmaybesameordifferentwithCH3 andC2 H5 attached.Thetransesterificationreactionisbasedononemoleoftriglyceridereacting withthreemolesofmethanoltoproducethreemolesmethylester(biodiesel)andone moleglycerol.
Severalkindsofalcoholscanbeincorporatedinthisreaction,suchasethanol,butanol, propanol,ormethanol.However,methanolismostcommonlyusedbasedonthelowcost,severalphysicochemicalbenefits(highpolarityandshortestalcoholchain(Maand Hanna,1999).
Thetransesterificationreactioninvolvesfewimportantparameterswhichsignificantly impactsthefinalyield.Someofthemostimportantvariablesare:reactiontime,freefatty acidcontentintheoil,reactiontemperature,watercontentintheoil,typeandamount ofcatalyst,molarratioofalcoholtooil,useofcosolventandmixingintensity.
1.3Integrationofwasteintobiodieselproductionprocess
Currentbiodieselindustrymostlyemploysedibleoilseedasfeedstockandstrongbase andacidbasedhomogenouscatalystmainlyduetohighconversionrates.However,high costsofthesetypeoffeedstocks,catalyst,andotherexpensiveprocess,suchaspurification offinalproductorseparationofcatalystmakesthewholecostofbiodieselexpensive andimpractical(Santosaetal.,2019).Inordertoreducetheproductioncost,research involvingtheincorporationofwastematerialsinseveralbiodieselproductionstagesis beingfavored.Therearevariousadvantagesinutilizingorreusingthewastematerials withdisposalandrecycleissues.Insteadofjustthrowingawaythewastematerialswhereit maydamagetheenvironment,utilizingitinbiodieselsolvesmultipleproblemsincluding
employmentgenerationforalargenumberpeopleinwasterecoveryandproduction stages.
Wastematerialshavebeenincorporatedinvariousbiodieselproductionstages viz. asfeedstockforbiodieselproductionorusingheterogeneouscatalystderivedfrom severalwastematerialsinsteadofhomogenouscatalyst.Theheterogeneouscatalysthave severaleconomicalandenvironmentaladvantagesinadditiontolowproductioncost, suchasitcanbeeasilyseparatedattheendofthebiodieselproductionprocessesby centrifugationorfiltrationandalsotheycanbereusedseveraltimes(Gotchtetal.,2009). Theseheterogeneouscatalystsaremuchsafertohandle,lesscorrosive,andmoreecofriendly(Lametal.,2010).Recentstudiesshowseveralkindsofwastesrangingfrom lignocellulosicwastes,shellwastes,andothershavebeensuccessfullyusedascatalystfor biodieselproduction.IncludingvarioustypesofCaCO3 basedwastesascatalyst,suchas wasteeggshell(Bhartietal.,2020),wasteshell(Yulianaetal.,2020),wastefishscales (Chakrabortyetal.,2011),wasteanimalbones(Farooqetal.,2015),wastecoralfragment (Roschatetal.,2012),andothers.Similarlyvariouslignocellulosicbiomasshasalsobeen investigatedforlowcostcatalystsuchassugarcanebaggase(Akinfalabietal.,2020),rice huskash(Hindryawatietal.,2014),bamboo(Zhouetal.,2016),palmshell(Baroutian etal.,2010),etc.
Severalwastesutilizedasbiodieselfeedstocklikewasteoil,animalfat,agricultural waste,municipalwaste,lignocellulosicwaste,etc.,havebeendiscussedindetailbelow.
1.4Wastematerialasfeedstock
Theincreasedenergydemand,growingconcernfortheenvironmentandthepossible shortageofpetroleumfuelsinfuturehaveincentivizedtheresearchtowardfinding alternativesustainablefuel(Paglianoetal.,2017).Biodieselhascomeforwardasa promisingalternativetopetroleumfuelwithsimilarphysicochemicalpropertiesasdiesel thatcanbeusedasitssubstituteindieselengineswithoutanyneedformodification (Mardhiahetal.,2017).Biodieselismostcommonlysynthesizedfromoilseedswhich stronglyinfluencetheglobalfoodsecuritywhileincreasingthepriceofedibleoils therebyshiftingthefocustowardsnon-edibleaswellaswastecookingoil(Patiletal., 2011).Theincorporationofmunicipal,domestic,andagroindustrialwastefeedstockfor biodieselproductionmakestheprocesssustainableandeco-friendly(Aboelazayemetal., 2018).
1.4.1Wasteoil
Biodieselareethylormethylestersextractedfromdifferentfeedstocksthroughthe processoftransesterification(Sharmaetal.,2013).Theavailabilityofwastefeedstock createsanattractiveoptionofovercomingtheenergycrisisbyconversionofthese feedstockstobiofuel.Wastecookingoil(WCO)presentsitselfasapromisingbiofuel
Table1.1 Fameyieldofwastecookingoil(WCO)underdifferentcatalysts.
S.No. Feedstock
Catalystused Reference
1. WCO 79.7% Sr/ZrO2 OmarandAmin,2011
2. WCO 81.0% ZS/Si Jacobsonetal.,2008
3. WCO 83.08% CaO/KI/ᵞ-Al2 O3 Asrietal.,2015
4. WCO 88% Lipase Saifuddinetal.,2009
5. WCO 90% Novozyme435 Haighetal.,2012
6. WCO 90% H2 SO4 Wangetal.,2006
7. WCO 91.7% KOH/Al2 O3 Noirojetal.,2009
8. WCO 94% PuroliteD5081 Haighetal.,2012
9. WCO 97.8% Acid-basedcatalyst OuachabandTsoutsos,2013
feedstocksinceitisawastethatisreadilyavailablefromhouseholdkitchens,restaurants, andcafeterias.Theutilizationofwastematerialsforbiodieselproductionwillbehelpful inmitigationofpollution.WCOwhichisgenerallydisposedoffaswastecanbeexploited asafeedstockmakingthewholeprocesseconomical(Arshadetal.,2018; Tangyet al.,2016).TheproductionofbiodieselfromWCOisdeemedtobecosteffective, technicallyviableandenvironmentallybenign(Farooqetal.,2013).Itisestimatedthat UnitedStatesofAmerica,Japan,China,Europe,andMalaysiatogetheraccountsfor 15milliontonnesofWCOgenerationperyearonanaverage.Indiaisoneofthe largestproducersofWCOwithanestimateof9.2milliontonsperannum(Bharti etal.,2020; Kolheetal.,2017). Cheetal.,(2012) usedolivepomaceoilfortheproduction offattyacidmethylester(FAME)viaacidesterificationprocesswithsulfuricacidas catalyst.Reductioninfreefattyacid(FFA)by50%atlowmethanoltooilratiowhile forhighmethanoltooilratioover80%reductionwasobserved.Furthermore, Ouachab andTsoutsos(2013) alsousedolivepomaceoilfortheproductionofFAMEthrough esterificationprocessachievingayieldof97.8%(Table1.1).
Theprocessoftransesterificationhaseliminateddurabilityandoperationalproblems whilereducingtheviscosityofvegetableoil.BiodieselblendofWCOinperformance characteristicsareclosetodieselfuel(Abedetal.,2018). Mohodetal.(2013) intheirstudy comparedB5andB10blendsofWCObiodieselwithdieselfuelbyusingitinasingle cylinderdieselengine.Thebiodieselblendresultedinreductionofthermalefficiency by2.8%andincreaseinspecificfuelconsumptionby4%. MuralidharanandVasudevan (2011) testedfourblendsofdiesel-WCObiodiesel;dieselfuel,B5,B20,andB30indiesel engineandfoundhigherfuelconsumptionloadinbiodieselblendssinceheatingvalueof biodieselislowerwhencomparedwithdieselfuel.TheWCObiodieselfuelsynthesized bytransesterificationprocessissimilartodieselfuelinitsphysicalandchemicalproperties. TheongoingstudiesfocusonthefunctioningofbiodieselblendofWCOwithdiesel fuelintheoperationofdieselenginewithoutanyalterationinhardware(Abedetal., 2018).
1.4.2Wasteanimalfats
Meatprocessingfacilitiesproduceanimalfatsasaby-product.Recentlyalotofattention ispaidontheeconomicallysustainablefeedstock,animalfatwaste(AFW)beingone ofthem(Habibetal.,2020).Theanimalfatderivedfromthemeatprocessingfacility mainlyincludewhitegreaseandlardfrompork,tallowsfromcattle,poultryfatfrom turkey,chickens,ducks,andotherbirds.Oilsandfatsderivedfromleatherindustry wasteandfishprocessingplantsarealsodeemedtobeaviablefeedstockforbiodiesel (Alptekinetal.,2012).Currently,animalfatforthemostpartisusedasrawmaterialin soapandcosmeticsindustriesmakingthemarketdemandforAFWverylimited.AFW offersenvironmental,economicaswellasfoodsecuritybenefitovertheconventional ediblevegetableoilswhenusedasafeedstockforbiodiesel.Additionally,thecostfor transesterificationofAFWi.e.,$0.4-0.5/literischeaperthanthetransesterificationcost ofvegetableoilwhichis$0.6–0.8/liter(Bankovi ´ c-Ili ´ cetal.,2014).SomeAFW,such aschicken,tallow,lardfatsarealreadyinuseforbiodieselproductionatindustrialscale (Bender,1999; SchörkenandKempers,2009).AFWsrequirecomplextechniquesfor biodieselproductionsincetheycontainhighlevelsoffreefattyacids(FFA)andsaturated fattyacidswhichresultsinlowerchemicalandphysicalqualityofbiodiesel.Despitethat, AFW’slowunsaturationoffattyacidshasnumerousadvantages,suchashighcetane number,highcalorificvalue,andhighoxidationstability(Alptekinetal.,2012).Since, AFWcontainshighquantityofFFAandwaterresultinginreducedyieldofbiodieselas wellasincreasedproductioncost,pretreatmentisessentialwhichalleviatestheproblem ofseparationandpurification(GebremariamandMarchetti,2018).Theproductionof biodieseltakesplacethroughtheprocessoftransesterificationwhichinvolvesreaction offatinthepresenceofacatalystwithshortchainalcohol.Therearemanycatalysts availableforuseintheproductionofbiodiesel(Toldrá-Reigetal.,2020).Catalysts,suchas potassiumhydroxide,potassiumamide,potassiummethoxide,potassiumhydride,sodium hydroxide,sodiumamide,sodiummethoxide,sodiumhydride,sulfuricacid,phosphoric acid,hydrochloricacid,organicsulfonicacid,lipase,zirconias,silicates,andnanocatalysts, aresomeofthemostwidelyusedalkali,acidic,generous,andcomplexcatalystsused intransesterificationreaction(MaandHanna,1999).TheuseofalkalicatalystinAFW transesterificationresultsinafasterreactionrate(4000timesfaster)incomparisonwith acidcatalysts.Theotherbenefitofusingalkalicatalystsisthatitisreadilyavailableand lessexpensive.VariousstudieshavebeenconductedusingAFWfortheproductionof biodiesel,fewofwhicharementionedin Table1.2
1.4.3Agriculturalwaste
Agriculturalcropresiduesoragriculturalwastescanbebroadlyclassifiedintotwotypes: 1. Fieldresidues:Materialswhichareleftinplantationareasoragriculturallandafter harvesting.Fieldresiduesgenerallyincludestalks,ricebran,stems,seedpods,etc.
Table1.2 Biodieselproductionfromdifferentanimalfatfeedstock.
Sl.No. Feedstock Catalyst Yield(%) Reference
1. Chickenfat
H2 SO4 99.01 Bhattietal.,2008
NaOMe 88.5 AlptekinandCanakci,2010
NanoCaO 88.5 Keihanietal.,2018
AC/CuFe2 O4 encapsulatedwith CaO 95.6 Seffatietal.,2019
CaO/CuFe2 O4 94.5 Seffatietal.,2020
Compositemembrane& NaOMe 98.1 Shietal.,2013
KOH 82.0 Chavanetal.,2017
2. Lard KOH 91.4 Mataetal.,2014 KOH 98.0 Heetal.,2020
35%CaO/zeolite 90.9 Lawanetal.,2020
Supercriticalmethanol 89.9 Shinetal.,2012
Immobilizedlipasefrom Candidaantartica 96.8 Adewaleetal.,2016
LipasefromCandidasp. 87.4 Luetal.,2007
LipasefromCandida antartica 74 Leeetal.,2002
LipasefromCandida antartica 97.2 Huangetal.,2010
3. Beeftallow KOH 90.8 Mataetal.,2014
Immobilizedlipasefrom Burkholderiacepacia 89.7 DaRósetal.,2010
Surfonatedpolystyrene 75 Soldietal.,2009 KOH 95 Moraesetal.,2008
4. Mutton tallow MgO-KOH 98.00 Liuetal.,2007
Bhattietal.,2008
2. Processresidues:Theleftovermaterialsafterthecropisprocessedtosomeusable resourcearecalledprocessresidues.Theseprocessresiduesmayincludehusks,roots, bagasse,seeds,anddeoiledcakesofedibleandnonedibleoilseeds. Ofwhichcornstover,rice,andwheatstalksandmostlydeoiledcakesofedibleand nonedibleoilseedshavebeenstudiedaspotentialfeedstocksforproducingbiodiesel mainlybecauseoftheremainingoilcontentafterprocessinginthem.Globalestimation showsthat38.5millionmetrictonsofricebranfrom482millionmetrictonsofrice isproducedannually(Pattanaiketal.,2019).Roughlythisricebrancontainsaround 17.5%oilandunrefinedricebranoilwith8%FFAcontentshowsgreatpotentialforthe productionofbiodiesel.SincethericebranhashighFFAcontent,itrequirescertainlevel ofpretreatment. Kattimanietal.,(2014) intheirstudyshowedbiodieselproductionin therangeof60%–80%afteracidcatalyzedesterificationwithsulfuricacidfollowedby
transesterification.Similarly, Zhangetal.(2013) conductedsimultaneousesterification andtransesterificationreactionfromricebranoilwith40%FFAtoobtainbiodiesel yieldof92%usingchlorosulfonicacidmodifiedzirconiaascatalyst.Whereas, Jitputti etal.(2006) performedtransesterificationofricebranoilwithsolidacidcatalystand statedthatsolidacidcatalystcanperformbetterthanmineralacidmainlyattributedto itsreproducibilityandheterogeneouscharacteristics.
Deoiledcakesofedibleandnonedibleoilseedslikeolivedeoiledcakehaverecently gainedmuchattentionduetotheirpotentialforbiodieselproduction.Theolivedeoiled cakeinaveragecontains19.75%oilcontentandhencehasbeenusedintwostep processestoproducebiodiesel.Theolivedeoiledcakeprimarilycontains24.5%FFA whichneedsesterificationreactiontoreducetheFFAcontenttoaround.52%followed bytransesterificationtoyieldbiodieselintherangeif40to65%(Al-Hamamre,2011).
1.4.4Wastewaterasbiodieselfeedstock
Wastewatercontainsnumerousmicroorganismsthatexploittheinorganicandorganic compoundspresentinthewastewaterforcarbon,nutrientsandenergy(Dufreche etal.,2007).Itisanobviousfactthattheproductionofwastewatersludgeisinlarge quantity.Ithasbeenreportedthatdrysludgeobtainedfromthewastewatercontains 5%–20%lipidw/wwhichisasgoodasplantseeds(Wangetal.,2016).Ithasbeen estimatedthatbecauseoftheuseofsludgeasalipidsourcethebiodieselproduction costwillbereducesimmenselysincesludgeisafreematerial.Sincewastewatersludge isrichinnitrogen,phosphorus,andcarbon,itcanbeusedasamediumforcultivation ofmicroorganisms.Microorganismsuchas Lipomycesstarkeyi,Rhodosporiumtoruloides, and Trichosporonoleaginosus havebeenrecognizedfortheircapabilityofassimilatingwaste forproductionoflipid(Xavieretal.,2017). Dufrecheetal.,(2007) throughinsitu transesterificationprocessfoundtheyieldofthedrysludgetobe6.23%. Sharmaetal., (2020) investigatedtwomicroalgalconsortiagrowninsewagewaterandfoundthelipid contentofonetobeincreasedby31.3%overtheotheraswellasdesirablefattyacids fortheproductionofbiodieselwerealsoobserved. Aroraetal.,(2020) observedhigh microalgalbiomassinwastewateraswellasenhancedlipidcontentofabout31%drycell weight.
1.4.5Wastecoffeegroundresidue
Coffeeisoneofthemostextensivelyconsumedbeveragesthroughouttheworldand hasbeensince1000years.Theconsumptionofcoffeeworldwidearound2015–1016was morethan9milliontonsaccordingtotheInternationalCoffeeOrganization(ICO,2016). CoffeaArabicaandCanephora/Robustaaretwospeciesofcoffeewithgreateconomic importance(Blinováetal.,2017).Worldwidetherearetoptenproducersofcoffee beans,withVietnamandBrazilbeingaccountableforalmosthalfofthetotalproduction
(DangandNguyen,2019).Spentcoffeeground(SCG)isawasteresiduethathasgained interestasapotentialbiodieselfeedstockaswellasasustainablewastereduction.The extractionofcoffeeoilfromdefectivecoffeebeansandcoffeegroundswasfoundtobe costeffectiveaswellasofhighqualityforbiodieselproduction.TheSCGfeedstockdue toitshighcontentofantioxidantexhibithigherstabilityislessexpensiveandpleasant smelling(Haile,2014).TheproductionofbiodieselfromSCGinvolvescollectionofthe coffeegroundanditstransportation,drying,extractionresultinginbiodieselproduction. Thecontentofoilvariesbasedonthecoffeesourcefrom11–20wt%.Theoilyield fromdefectivecoffeebeanrangesfrom10-12wt%onthebasisofdryweightwhileSCG produce10–15wt%(Al-Hamamreetal.,2012).
1.5Feedstocksgeneratedusingwastematerial
Utilizationofwastematerialfortheproductionofmicrobiallipidsforthebiodiesel synthesis,suchasnutrient-richwastewater,canprovidelowcostmediumforthe productionofvaluablefeedstocks.Microbiallipidsproducedinwastewateralsohelps inremovalofexcessnutrients(suchasphosphorusandnitrogen),avoidingdisposalof wastewaterintowaterbodiesbecausephosphorusandnitrogencauseeutrophicationof riversandlakestherebyalsohelpinginprotectingenvironment.
1.5.1Microalgaecultivationusingwastewater
Currently,microalgaeisconsideredoneofthepromisingalternatefeedstockforproducingbiodieselmainlyduetorapidgrowthrate,highlipidconcentrationandhighGHG fixingcapacity(Alametal.,2012).Cultivationofmicroalgaerequireslargeamountof nutritionwhichmakesitafairlyenergyextensiveandexpensiveprocessandtherefore researchersarestudyingvariousmethodstoreducetheproductioncost.Oneofthemost prominentbeingmicroalgaecultivationusingwastewaterwhichincorporatesproduction ofmicroalgaeandremovalofnutrientsfromwastewatersimultaneously.Thismethod servesmultiplepurposeofsavinglargeamountofwaterrequirementformicroalgae cultivationandnutrientsfromgoingtowastebyconvertingthenutrientavailable inwastewater(particularlynitrogenandphosphate)intomicroalgalbiomassthereby sequesteringlargeamountofcarbondioxideaswell(delaNoüeetal.,1992).Mostofthe microalgaespecieshavetheabilitytogrowfairlywellundernutrientrichwastewaterby absorbingthenutrientandmetalfromthewastewater.Severalspeciesofgreenmicroalgae havebeenusedinexistingwastewatertreatmentpondsfortreatingthewastewatersof industrial,agricultural,andmunicipalsourcesmakingthemanappealingmeansoflowcostandsustainablewastewatertreatmentalternative.Therefore,thegreenmicroalgaeare consideredasideallysuitedfordualroleofbiomassproductionandphytoremediation byconvertingnutrientspresentinwastewatertocarbohydrateandlipids(Rawatetal., 2011).
Table1.3 Biomassproductivityofmicroalgaecultivatedindifferenttypesofwastewater.
Sr.No. Microalgaespecie Wastewatertype Biomass productivity/day Reference
1. Chlorellavulgaris Aquaculture wastewater 42.6mgL-1 Gaoetal.,2016
2. Scenedesmussp. Industrial wastewater 900mgL-1 Jebalietal.,2015
3. Chlorellavulgaris Poultrylitter wastewater 127mgL-1 Markou,2015
4. Chlorellavulgaris Municipal wastewater 0.251gL-1 Gaoetal.,2014
5. Goniumsp. Textileeffluent 0.53gL-1 Boduro ˘ gluetal.,2014
6. Scenedesmusobliquus Urbanwastewater 380mgL-1 Ruizetal.,2013
7. Chlorellapyrenoidosa Piggery wastewater 0.3gL-1 Wangetal.,2012
8. C.pyrenoidosa Soybean processing wastewater 1070mgL-1 Hongyangetal.,2011
Severalkindsofwastewaterwhichhasbeeninvestigatedfortheproductionof microalgalbiomassaredepictedin Table1.3.
1.5.2Oleaginousfungigrownusingwastewater
Somefilamentousfungihavethepotentialtoaccumulatehighcontentoflipidsforthe productionofbiofuelsarecalledoleaginousfungi.Examplesofsomeoleaginousfungi include Mucorcircinelloides (Songetal.,2001), Cunninghamellaechinulate (Fakasetal.,2009), Mortierellaalpina (Wangetal.,2011), Umbelopsisisabellina (Hardeetal.,2016),etc.These oleaginousfungispeciesarecurrentlyattractingmuchattentionmainlybecauseofhigh concentrationoflong-chainpolyunsaturatedfattyacids(PUFAs).
Differentkindsofwastewatershavebeenincorporatedbyseveralresearchersforthe productionofoleaginousfungiadvantagebeingutilizationofwasteasnutrientsource forgrowingthefeedstock.Suchas Munirajetal.,(2015) showedthatpotatoprocessing wastewatercanbeeffectivelyusedforthecultivationoftwooleaginousfunginamely Aspergillusflavus and Mucorrouxii withhighlipidcontent.Similarly, Munirajetal., (2013) alsousedpotatoprocessingwastewaterfortheproductionofmicrobiallipidusing filamentousoleaginousfungusspecieAspergillusoryzae.Theresultshowedsubsequent amountoffattyacids,suchasoleicacid,palmitolicacid,palmiticacid,etc.Inadifferent study, SubhashandMohan,(2015) investigatedthepotentialoftwolignocellulosic wastewaterofcorncobwasteliquorandpapermilleffluentbyusingoleaginousfungi specie Aspergillusawamori. Resultsshowedthatavailabilityofsimplemonomericcarbon
compoundsintheselectedlignocellulosicwastewatergreatlyinfluencedbothlipid productivityandfungalgrowth.
1.6Challengesandfutureprospects
Currently,thebiodieselindustryismostlybasedontheavailabilityofoilseedforthe productionandtheutilizationofwasteindifferentstagesofbiodieselproductionreduces theassociatedcost.However,theproductionprocessmostofthetimesarenotasefficient asthatwithoilseed.Thereforealotofresearchisstillrequiredfirstlytosearchmore compatiblewastederivedfeedstockandoptimizetheoverallproductionprocessto competewiththeoilseedbiodieselproduction.Theprospectofutilizingawastematerial tosynthesizeheterogeneouscatalystssurelyisapromisingalternativetohomogenous catalystseliminatingvariousdisadvantagesofhomogenouscatalysts.Therefore,secondis explorationofmorewastederivedcatalystwhichcanreducetheoverallproductioncost andincreasetheproductionefficiency.Furthermore,alotofinvestigationofwastebased feedstockandwaste-derivedcatalystarenecessarytoimprovetheoverallperformance forbiodieselproductionincomparisontoconventionalfeedstockandcatalystaswellas otherchemicalprocessesinvolved.
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