绿色化学：第五章 绿色化学技术

Chapter5

绿色化学技术5.1

Theperformanceofcatalystsinchemicalreaction5.2

Greenchemistryandcatalysis5.3

Thedesignofhighefficientandsafecatalyst5.4

Changingstartingmaterialforchemicalreaction5.5

Changingreagents5.6

Changingthesolventofchemicalreaction5.7

Processcontrolandprocessintensification5.1

TheperformanceofcatalystsinchemicalreactionThefunctionofcatalyststo

chemicalreactionAcceleratethechemicalreactionrateNamely,theuseofcatalystscancontroltheselectivityforspecialproducts.Synthesizethespecialconformationofchiralisomers（手性异构体）Incorporatewithreactionconditions,andcontroltheselectivityofchemicalreaction.Catalysthasbeencalledas

molecularmachine

allthereactionsinbiomassarecatalyzedbyenzymewithhighspecificities,selectivityandatomeconomy.MolecularMachine

Recentinvestigationshavereportedthatnotonlyenzymeactsasmolecularmachinebutalsothecommoncatalystsownthesimilarfunctions.Theclassicalexampleisthemetalcyclopentadiene(环戊二烯)complexwhichwasusedasthecatalystinolefin（烯烃）polymerizationCatalysthasbeencalledas

molecularmachine

continueZiegler-Nattacatalyst:mechnsim?。

Enzymeandothertraditionalchemicalcatalyst.Iftheyexhibithighspecificity,selectivity,yieldandatomeconomy,theyshouldbeconsideredasthemolecularmachinewithspecialfunctionsinchemicalreactions.Catalysthasbeencalledas

molecularmachine

5.2GreenChemistryandCatalysisCatalysisandPollutionProtectionTheactivationofnewstartingmaterials

CatalysisandProcessPromotion

Automobileexhaustpurifyingcatalyst(threewayconversioncatalyst,TWC)CatalysisandPollutionProtectionCatalystreactiononTWC

CxHy+O2CO2+H2OCO+O2CO2NOx+COCO2+N2

CompositionofTWC

Activecomponent:Pt,Pd,Rh

Supports:γ-Al2O3,Cordierite（堇青石）Additive：Ce，La，Ba，ZrCatalyticcombustionHighTemperature,NOX.LoadcatalystLowerTemperatureHigh-temperatureflameisoftennotcompletecombustionoffuel.Inadditiontogeneratingcarbondioxideandwater,sidereactionswilloccurinthehightemperatureflameproducingtoxiccompoundssuchasNOx,COandCxHy.

thecatalyticutilizationofCO2Energy-savingandRecoveryofcarbondioxidefromfluegasExploitingCarbondioxideasaresource

CO2+H2CH3OHGasoline

Catalysisplaysaimportantroleinnewlysynthesize

routewithoutpollutionThechemicalreactionmaybecomemoreeffectiveandmoreselectiveovercatalyst,whichcandecreasetheformationofby-productsandotherwastes.Catalystscanimprovethereactionconditions,suchastemperature,pressureandenergyconsuming,andeliminatetheusageoftoxicreactionmedium.

Inshort,theutilizationofcatalystcansatisfytherequirementsofGreenChemistry,simulatouslyThesynthesisofpyrocatechol

Traditionally:Benzeneisharmful，Toomanysteps，By-products(ketenehydroquinone)，SO2isnotsafechemicals,continueTheactivationofnewstartingmaterials

Draths&Frostglucose（葡萄糖）asstartingmartialAvoidtheusageoftoxicandharmfulchemicalsandsharplydecreasetheyieldofby-products.CH2=CH2O2PdCl2CuCl2水溶液

CH3CHO

Disadvantages:ConsumelargeamountofcatalystsTheconsternationofCl-isgreater,andcanleadtotheformationofchromateby-products.Thoseby-productsisharmfultohumanhealthyThesynthesisofaceticaldehyde

3.CatalyticProcessPromotion

ThesynthesisofhydrochinoneTraditionalMethod：Disadvantage:toomanysteps,alargemountofby-product,corrosivechmicals(H2SO4,HCl)Environmentalbeigenmethod:

Advantages:Greenermethod:Shortreactionchain，By-productsonlyformattedinthefinalstep.R1C(OH)R2R1COR2cat.microwaveVarmaetal:theactivationundermicrowaveandcatalystTraditionallyOrganicsolvent;CrO3,KMnO4;SlatpollutionThesynthesisofcarbonylcompoundsConversionofBiomassBamboosSmallMoleculesSuchas:CH3COOH,CH3OHetcNewCatalysts

5.3TheDesignofHighEfficient

andSafeCatalyst1:Grossanalysis

1.Atfirst,analyses:thepossibilityofreactionandthelargestequilibriumyelidtheoptimizedreactionconditiontheavailablemartialsatomeconomyofreactioninrealreactioneconomyofcatalystseconomyofcatalyticreactionsinordertounderratedthereliabilityofrealcatalysts2.Severalfactorsshouldbeconsideredtodesignparametersofcatalysts.activity,selectivity,stability,durationandtoxicity,etc3.Accordingtothereactionroutes,searchthecatalystandpossiblestartingmaterials,choosethemostfavorablecatalysts,modifyandoptimizethereactionconditions.4.Confirmthereactionpossibilityexperimentally.Iftheexperimentsdonotconfirmthetheoreticalperdition,theprocessshouldbere-designed.Grossanalysis

2.designanddevelopthenewtypemoleculeoxygenoxidativecatalystsTraditionalinorganicoxidants：NaClO,NaBrO,HNO3,KHSO3,CrO3,KMnO4,KCr2O7,etc.Thetraditionalinorganicoxidativecanintroducealargeamountofwastesalts,hazardousgasesandliquidsheavyatomsO2:ThecleanestoxidativechemicalThelimitationofitsreactionconditions,OftencompaniedbyotherauxiliaryoxidantsCleanoxidantsandtheircharactersCleanoxidativeandtheircharactersH2O2H2O2containmorethan47percentactiveoxygen,anditsoxidativeproducts(water)isenvironmentalbenignchemical.H2O2ismoreexpensivethanO2andO3,andcandiscorporateinroomtemperature

O3：O3isalsotheenvironmentalbenignchemicaloxidative,anditsoxidativeproductsisoxygenmolecule.ButtheusageofO3oftenrequiresomespecialmethodandequipments.CleanoxidativeandtheircharactersO3tubetransformerN2O：itsoxidativeproductsisenvironmentalbenignproduct(N2)thesynthesisofN2OiscomplexandthecostofN2Oisveryhigh.CleanoxidativeandtheircharactersLatticeoxygen:Catalyst:multivalenttransitionmetalcompositeoxidesOxidants:oxygenandairRedoxcircleCatalyticmembranereactorAdvantages:HighselectivityNodangerofexplosionEasyseparationofreactantsDesignofoxidativecatalystbasedonthereactionmechanismThereactionmechanismofdifferentreactionsystem,includingcatalysts，mayvary.Hence,therequirementsforcatalystsshouldalsobedifferent.Thedesignofcatalystsshouldbetoughlyconsideredthereactionmechanismtomeettherequirementofreaction.Metalcomplexes

Thosemetal-organicscatalystsarewidelyusedinhomogenouscatalyticreactionsChiralmetalcomplexeshavebeenusedashomogenouscatalyst，andcancontrolthestereo-selectivity（立体选择性）ofthereaction.Itisveryimportantforhighstereo-selectivitytosearchthesuitablereactionconditions,propercentralmetalionsandchitalgroups(手性基团）.3、Thedesignofnew-typemetalcomplexcatalystsSample：thesynthesisofNaproxenTheyieldoftargetproduct(S-Naproxen)reaches97%。

Table5-2SomemetalcomplexesinindustryChiral

complesxIndoctrinationtimeRuBINAPAminehydrogenation1991RuBINAPchinoiline1987（Isoquinolalkaloid）RuBINAPTerpenealcoholhydrogenation1987RuBINAPKetenehydrogenation1911CuSthiffbaseComplexes1985（Cyclopropanationofolefins）RhBINAPhexahydrothymol19904,DesigningofNewMolecularSieveCatalyst

MolecularSieve(分子筛)Molecularsievereferstoakindofinorganicpolymercomposedofaluminumsilicate(siliconaluminate),bearingopenstructure.Structurally,

molecularsievebearsthetetra-XO4structure,inwhichoneatomXsharesOwithotherXatoms.Xmaybetri-(Al,B,orGa),tetra(Ge,Si)-,orpenta-(P)valent.DesigningofNewMolecularSieveCatalyst

DesigningofNewMolecularSieveCatalyst

Theporediameterofmolecularsieveisdependantonthenumberofbuildingunits,andthemolecularsieveisgenerallynamedmacro-,meso-,ormicro-molecularsievecorrespondedrespectivelytothemeanporediameterof0.75,0.67or0.43nm.NaturalMolecularSieve（Zeolite）iswidelyusedinpetrolrefineryforitsmacroporestructure.Synthesizedzeoliteisnowcommercializedandhasbecomeoneofthemostimportantcatalystinpetrolindustry.DesigningofNewMolecularSieveCatalyst

XNaturalMolecularSieve（Zeolite）isalsousedinionexchangeprocess.BecauseNaturalMolecularSieve（Zeolite)oftenownsacidandbasesitesstimulatously.Incatalysis,molecularsieveiswidelyusedasanewacid-basecatalystintherelatedreactionssuchastheconversionofalkanes.DesigningofNewMolecularSieveCatalyst

Thealkylattionofbutene：Traditionalmethod：HFand/orH2SO4areusedasthecatalysts.Advantage:highefficiencyDisadvantages:erosionofHF/H2SO4productionofinorganicsaltsHFcouldberecycled,butH2SO4couldnotandshouldberemoved.theuseofsolidmolecularsieveacidcatalyst：Theerosionofliquidacidiseliminated，Noinorganicsaltsaswastesproduced.SolidacidcatalystMolecularSievecouldalsobeusedasbasiccatalystsoracidic-basicbifunctionalcatalystalreadyusedfortheproductionoffundamentalchemicalsbutnotaswidelyasacidcatalystsItwillundoubtedlyplayanimportantroleintheproductionoffinechemicalsandspecialchemicals.Forexample,CsMolecularsieveisusedinthesynthesisof4-methyl-thiazoline(4-甲基噻啉，onekindofanti-fungus)insteadofCl2orCS2andNaOH.

ChangingtheselectivityofachemicalreactionoriginatedfromtheshapeofmolecularsievebychemicalmodificationofmolecularsieveTheselectivityofchemicalreactionsbasedontheshapeofthemolecularsievecouldbealteredbychemicalmodificationofthemolecularsieveusedasthecatalysts,thisprovideswideapplicationsofmolecularsieveincontrollingchemicalreactions.For

ExampleInthesynthesisof2,6-di-isopropylnaphthalene,amixtureof2,6-,2,7-,and2,4-substitutednaphthaleneisobtainedusingordinarymethods.

2,4-di-isopropylnaphthalene+2,7-di-isopropylnaphthalene2,6-di-isopropylnaphthaleneThetraditionallyusedcatalystSiO2/Al2O3haslargepores,andcouldnotdistinguish3-substituted-isopropylnaphthalenefrom4-substituted-isopropylnaphthalene,andthedistinguishof

2,6-di-isopropylnaphthalenefrom2,7-di-isopropylnaphthalenecouldneitherberealized.Theseparationof2,6-di-isopropylnaphthaleneand2,7-di-isopropylnaphthalenebyusingspecialpolymerliquidcrystalisverytroublesomeandveryexpensive.For

ExampleTheuseofsmallporemolecularsievecouldinhibittheformationof3-,or4-,substitutedproductsbuttheformationofequivalentamountof2,6-and2,7-substitutedproductscouldnotbeavoided.Theformationof3-and4-substitutedproductscouldbeeliminated,andaratioof2,6-to2,7-substitutedproductsof7/3couldbeobtainedbyusingZeolite-Casthecatalyst.Table5-3givesoutthedistributionofproductsbyusingdifferentkindsofcatalysts.For

ExampleTable5-3，ThedistributionoftheproductsfromthealkylationofnaphthalenebyusingdifferentkindsofcatalystsCatalystPorediameter/nm2,6-/2,7-2,6-isomer%SiO2/Al2O36.0132L-molecularsieve0.710.822B-molecularsieve0.73137C*zeolite0.72.770ZSM-50.55Verylowactivity

Prospectfortheresearchofmolecular

sievecatalystsMolecularsievecatalystsmayreplacesuchsubstanceasHF,H2SO4,etc.,whichareobviouslydangeroustopeople’shealthandtheenvironment.Thus,molecularsievecatalystisregardedasonekindofenvironmentallybenigncatalyst.Simultaneously,onaccountofthesignificantincreaseoftheactivityandselectivityduetotheuseofmolecularsievecatalyst,theresearchofmolecularsievecatalystwillundoubtedlybecomeoneofthemostpromisingfieldingreenchemistry.Chapter5Techniques

inGreenChemistry5.1

TheperformanceofCatalystsinChemicalreaction5.2

GreenChemistryandCatalysis5.3

TheDesignofHighEfficientandSafeCatalyst5.4

ChangingStartingMaterialforChemicalreaction5.5

ChangingReagents5.6

ChangingthesolventofChemicalReaction5.7

ProcessControlandProcessIntensificationReferences5.4ChangingStartingMaterialforChemicalReactionSelectionofstartingmaterialsThefeedstockhasgreatinfluenceontheefficiencyofthesyntheticroutes,ontheenvironmentaleffectsandthehealthyofhumanbeings.Thehazardoffeedstockmustbeconsideredbytheproducers,managersinthepreservationandtransportation,aswellastheoperatorsintheprocessing.Forsomebulkchemicals,thechangeoffeedstockmaychangethemarket,forsomesubstanceareproducedjusttoprovidecertainfeedstock.1.Reducinghazardousproperties(1).Certainly,afirstlevelassessmentofanystartingmaterialmustbewhetherthesubstanceitselfisbenign;whetheritposesahazardforhumanbeingsandfortheenvironments;whetheritposesahazardintheformofeithertoxicity,accidentpotential,ecosystemdestruction,orotherform;whetheritisdestructivefortheecologicalenvironmentwhetheritposesotherun-benignproperties(2).UsingpreferablesourcesCurrently,morethan90%organicstartingmaterialsarealmostexclusivelyderivedfromnon-renewablecarbonfeedstocks,suchascoalorcrudeoil.Petrol-refineryisenergyconsuming.Forexample,intheU.S.,theamountofenergyconsumedinpetrol-refineryisabout15%ofitsenergyconsumption.Thecostwillaugmentforthequalityofthecrudeoilisbecomingbad.Intheproductionoforganicchemicalsfromoil,oxidationreactionsareusuallyemployed,anditiswellknownthatoxidationreactionsareseriouslypollutant.usingpreferablesourcesConsideringtheuseupofoil,naturalgasandcoal,wemustreduceourdependenceonthesefossilresources.Agricultureresourcesandbio-resourcesaregoodalternative.Recentstudiesshowthat,manyagricultureresources,suchascorn,potato,soybean,andsooncouldbeconvertedtotextiles（纺织品）ornylon.Agriculturewaste,biomasscontainingcellulose（纤维素）andlignin（木质素）couldalsobeconvertedtochemicals.2.Advantagesanddisadvantagesofbiomassasachemicalfeedstock(1).Advantagesadvantagesbiomasscanbebrokedownintoahugearrayofstructurallydiversematerials,frequentlystereochemically（立体化学的）andenantiomerically（对映体的）defined,givingtheuserawiderangeofnewstructuralfeaturestoexploitinsynthesis.Thestructuralcomplexityofthebuildingblocksavailablefrombiomassisfrequentlyhigherwhencomparedtobuildingblocksderivedfrompetrochemicals.Thispropertycouldleadtoareductionofreactionsideproducts,andhence,areductionoftheamountofwastematerialproducedinchemicalprocessesifmethodologywereavailabletoincorporatethiscomplexityintofinalproducts.

advantagesBuildingblocksisolatedfromcrudeoilarenotoxygenated,yetmanyofthefinalproductsofthechemicalindustryare.Therearefewwaystoaddoxygentohydrocarbons,andmanyofthemrequiretheuseoftoxicreagents(chromium,lead,etc.)instoichiometricamountsresultinginseverewastedisposalproblems.Biomassderivedmaterialsareoftenhighlyoxygenated.advantagesIncreaseduseofbiomasswouldextendthelifetimeoftheavailablecrudeoilsupplies,andthenmakecontributiontosustainabledevelopmentandmakesuretheproductionofcertainchemicalsthatcouldonlybesynthesizedfromoil.TheuseofbiomasshasbeensuggestedasawaytomitigatethebuildupofgreenhouseCO2intheatmosphere.SincebiomassusesCO2forgrowththroughphotosynthesis,theuseofbiomassasafeedstockresultsinnonetincreaseinatmosphericCO2contentwhentheproductsbreakdownintheenvironment.

advantagesAchemicalsindustryincorporatingasignificantpercentageofrenewablematerialsissecurebecausethefeedstocksuppliesaredomestic,leadingtoalesseneddependenceoninternational‘hotspots’.advantagesBiomassisamoreflexiblefeedstockthaniscrudeoil.Crudeoilisformedanditscompositionsetbygeologicalforces.Thediversityofbuildingblocksfrombiomassoffersagreatopportunityfortheproductionofarangeofchemicalsaswideasthatavailablefromnon-renewables.Withtheadventofgeneticengineering,thetailoringofcertainplantstoproducehighlevelsofspecificchemicalsisalsopossible.advantages（2）、disadvantages

Manyofthereporteddisadvantagesarerelatedtocurrenteconomiccircumstances.Thepetrochemicalindustryishugeandhighlyefficient,fromtheinitialremovalofcrudeoil,totheextractionofthesimplerbuildingblocksthatcomprisethecrudeoil,throughthefinaltransformationofthesebuildingblocksintotheirmanyintermediatesandchemicalproducts.Moreover,thepetrochemicalindustryiswellestablished.Muchofitscapitalinvestmentispaidoff.Themechanismsandoperationofitsprocessesarewellunderstoodandgivesingleproductsofhighpurity.Thebiomassindustryisstilldevelopingprocessesthatpossessthesefeatures.disadvantagesManyofthebiomasssourcesbeingconsideredaschemicalfeedstockshavetraditionallybeenusedassourcesoffood,andthejustificationfordivertingpartofthisresourcetochemicalproductionhasbeenquestioned.Theissuebecomesmoreacutewhenbiomassisconsideredasafeedstockforfuelaswellaschemicalproduction.Biomassalsorequiresspacetogrow,andtheenvironmentalimpactoflargescalebiomassplantationshasbeenexamined.

disadvantagesTraditionalsourcesofchemicalfeedstockshavebeenreferredtoas‘threedimensional’becausethestructuresinwhichtheyarefoundhavedepthaswellaslengthandwidth.Thepresenceofthethirddimensionallowsmuchmorefeedstocktobeconcentratedinasmallerarea.Incontrast,biomassfeedstocksare‘twodimensional’feedstocks,andrequireproportionallymorespaceforthesameamountofmaterial.disadvantagesBiomassisnecessarilyseasonal.Thecropisplantedinonepartoftheyear,andharvestedinanother.Thisleadstopeaksandvalleysinthesupplyoffeedstock;yetthechemicalproducerplanningtousebiomassneedsaregulardaytodaysupply,andneedstobeassuredthatthematerialusedatthebeginningoftheyearwillbeofthesamequalityasthatusedattheendoftheyear.disadvantagesThewiderangeofmaterialsthatcomprisebiomasscouldbeadetrimentespeciallyifnewprocessesneedtobedevelopedforeachfeedstock.Moreover,thebuildingblocksextractedfrombiomassareforeigntotraditionalchemicalproducersandmustbedemonstratedtofunctioninamannersimilartoexistingbuildingblockswithoutunduemanipulation.disadvantagesChapter5Techniques

inGreenChemistry5.1

TheperformanceofCatalystsinChemicalreaction5.2

GreenChemistryandCatalysis5.3

TheDesignofHighEfficientandSafeCatalyst5.4

ChangingStartingMaterialforChemicalreaction5.5

ChangingReagents5.6

ChangingthesolventofChemicalReaction5.7

ProcessControlandProcessIntensificationReferences

5.5ChangingReagents

SelectionofreagentsManyprogresshavebeenachievedinthisaspectongreenchemistryForexample：

Usinglightinsteadofsomereagents;Usingrecoverablecatalystasitispossible;Loadingthereagentsonthesupporttorealizethereactions(usingoxidativeagents,reductiveagentstorealizetheloading)

Highsyntheticefficiency;practicable;benigntohuman’shealthandtheenvironmentSelectionofreagentsForexample,fortheoxidationoftertiaryhydrocarbonstoketones,thetraditionalmethodinvolvesthereactionofcopperacetateandhydrogenperoxideintheaqueoussolution,whereas,thisreactioncanalsobewellrealizedbysupportingnitrateofcopperontothehydrogenperoxideimpregnatedK10clay.Highsyntheticefficiency;practicable;benigntohuman’shealthandtheenvironment5.6

ChangingreactionsolventIssolventnecessaryforthereaction?AqueoussolutionsystemIonicliquid

Immobilizationofthesolvent——SolutionofpolymerCarryingoutpolymerizationreactionsusingthesolventasoneofthemonomertoobtainpolymerized-solvent-derivatesthatbearthepropertyofthesolvent.Sincethissolventisanchoredonthepolymer,thustheseparationoftheproductsfromthesolventiseliminatedandpollutionfromthevolatilesolventisalsoeliminated.Solvent-freereactionBandgeretalcombinetheuseofenvironmentallybenigncatalystandmicrowavetosynthesis3-carbinyl-coumarinfromdi-methyoxybenzaldehydeandMeldrumacidwithoutusingsolvent.

Thecombinationofmicrowaveandcatalystinsteadofsolventiseffectiveinsuchprocessesasgroupprotection,deprotection,oxidation,reduction,rearrangementreaction.SupercriticalRegionPressureCriticalPointTemperaturePcTcLiquidVapourSolid超临界区FormationofSCFCO2FormationofSCFCO2Transmissioncharacters

ofSCFSCF:Density:Similartoliquid;Viscosity:1/100thanliquid:Liquidity:muchbetterthanliquidReynoldsnumber:muchbetterthanliquid(samecurrentvelocity)。Transfercoefficient:muchbetterthanliquid;NewtonFormulaμ=τyx/dμx/dy

Withtemperatureincreasing,forgas:Viscosityincreasesforliquid:Viscositydecreases.

SCF:Itsviscosityisnotequaltothatofliquidorgas.ButitisliabletothatofliquidViscosityPartialmolarvolumeInSCF，thepartialmolarvolumeofinfinitedilutionsoluteisnegativeNearthecriticalregion,itwillfurtherbecomemorenegative(about-1000∼16000ml/mol)AdvantagesofSCFinchemicalreactionsolvent1.ItisconvenienttoadjusttheprosperityofSCFfromlikegas-likephasetoliquid-likephaseintermofcontrollingpressure.Thatistosay,thecontrolofpressurecanaltertheprosperityofSCF,whichmakesthereactionbecomemoreeffective.2.ThecontrolofpressurecanadjustthedensityofSCF,andcanalsoadjustotherpropertiesrelatedwithdensity,suchasdialecticconstantandviscosity,whichpromotethepossibilitiestocontrolreactionandtoincreasesthereactiveselectivity.3.SCFalsoowncharacteristicslikesomegases,suchaslowviscosity,largediffusioncoefficient,whichismuchimportanttoacceleratethereactionrate,especiallytothosereactionsincludinggaseousreactants.Anotheradvantageofnon-oxidizabilityforSCFCO2makesitbecomeanidealreactionsolvent.ThehighconcentrationofCO2inSCFCO2makeitliabletoreactinitsSCFcondition,whichacceleratethereactionrateandmakesomereactiontooccur.AdvantagesofSCFinchemicalreactionsolventChapter5Techniques

inGreenChemistry5.1

TheperformanceofCatalystsinChemicalreaction5.2

GreenChemistryandCatalysis5.3

TheDesignofHighEfficientandSafeCatalyst5.4

ChangingStartingMaterialforChemicalreaction5.5

ChangingReagents5.6

ChangingthesolventofChemicalReaction5.7

ProcessControlandProcessIntensificationReferences

5.7ProcessControlandProcessIntensification

ThemonitoringAndcontrollingofChemicalProcessProcessintensificationIfsmallamountofadangerouspollutant(X)willformintheprocessofareactionasaside-product,anditsformationisfacilitatedunderhighpressureandathightemperature,insitumonitoringoftheformationofXcouldbeappliedtodetectcontinuouslyproductionofX,andifitsconcentrationsurpassesacertainthreshold,thereactionconditions(temperatureandpressure)willbechangedimmediatelytoreduceitsproduction.

1.ThemonitoringandcontrollingofChemicalProcessOtherreactionparameters,suchastheratioofthefeedandsooncouldalsobecontrolledinsitutofacilitateorinhibittheformationofcertainproduct.2.Processintensificationastrategyformakingdramaticreductionsinthesizeofachemicalplantsoastoreachagivenproductionobjective.

Definition:viaimprovementoftechnicalmethodsviaimprovementoftechnicalmethods2.Processintensification

ProcessintensificationviaimprovementofequipmentThesereductionscancomefromshrinkingthesizeofindividualpiecesofequipmentcuttingthenumberofunitoperationsorapparatus

ProcessintensificationviaimprovementofequipmentStaticMixerReactorMonolithicCatalystMicroreactors（1）Static-mixer-reactor(SMR)

Thetechnologyofstirringhasbeengreatlyintensifiedduringthelast30years.Surprisingly,thiswasachievednotbyimprovingmechanicalmixerbutquitetheoppositebyabandoningthem—infavorofstaticmixer.Thesedevicesarefineexamplesofprocess-intensifyingequipment.Theyofferamoresize-andenergy-efficientmethodformixingorcontactfluid.

SulzerSMRstatic-mixer-reactor,whichhasmixingelementsmadeofheat-transfertubes,cansuccessfullybeappliedinprocessesinwhichsimultaneousmixingandintensiveheatremovalorsupplyarenecessary,suchasinnitrationorneutralizationreactions.SulzerSMRstatic-mixer-reactorOneofthemoreimportantdisadvantagesofstatic-mixing-reactoristheirrelativelyhighsensitivitytocloggingbysolids.Therefore,theirutilityforreactionsinvolvingslurrycatalystsislimited.Sulzersolvedthisproblem(atleastpartially)bydevelopingstructuredpackingthathasgoodstatic-mixingpropertiesandthatsimultaneouslycanbeusedasthesupportforcatalyticmaterial.(2).MonolithiccatalystMaterialsusedinthepreparationofmonolithiccatalysts:MetallicorNon-metallicsubstratesWhichcouldprovideamultitudeofstraightnarrowchannelsofdefineduniformcross-sectionalshapes.Toensuresufficientporosityandenhancethecatalyticallyactivesurface,theinnerwallsofthemonolithicchannelsareusuallycoveredwithathinlayerofwashcoat,whichactsasthesupportforthecatalyticallyactivespecies.Thecharacteristicsofmonolithiccatalystsverylowpressuredropinthesingleandtwophaseflow,onetotwoordersofmagnitudelowerthanthatofconventionalpackedsystems;highgeometricalareasperreactorvolume,typically1.5-4timesmorethaninthereactorswithparti