工业催化原理英文课件

CatalysisandIt’sReactionKinetics

ByXuzhude&JiangXianzhengDepartmentofChemistryZhejiangUniversityCatalysisandIt’sReactionKi1Chapter1IntroductionandBasicConception

§1.1 SignificanceofcatalysistomodernchemicalindustrySomeconceptscatalysiscatalystcatalyticactivitycatalyzedreactionChapter1IntroductionandBas2Theimportanceofcatalyst

Thefirstcatalyticprocessofindustrialsignificancewasdevelopedasearlyas1875.ItisPlatinum(Pt)catalyzedoxidationofSO2toSO3whichwasthenconvertedtosulfuricacidH2SO4Therearenosuchprogressesofmodernchemicalindustrywithoutcatalysis

Morethaneightypercents(80%)ofchemicalengineeringprocessesinvolvecatalysis

TheimportanceofcatalystTh3Severalimportantappliedfieldsofcatalysis

SynthesisofAmmonia--atypicalillustrationforthedevelopmentofcatalyst

Fe-Al2O3-K2ON2+3H2

2NH3thisreactionalmostcannotbeobservedattheatmospherepressureandroomtemperatureeventhroughitsGisnegative.BASFfirstachievedtheindustrialprocessofammoniasynthesisin1910,andwontheNobelprizeof1932.Severalimportantappliedfiel4Severalimportantappliedfieldsofcatalysis

Petroleumrefiningcatalyzedcrackingofcrudeoiland/orheavyoiltoenrichthelightoilcomponents.Hydrocarbonwithlargermolecularweightcrackstosmallermolecules. SiO2-Al2O3,ZSM-5zeoliteReforming:convertingalkylhydrocarbontoaromatichydrocarbonPlatinumPt

Severalimportantappliedfiel5Severalimportantappliedfieldsofcatalysis

Polymer:Synthesizedfiber,robber,andplasticpolymerizationofolefin(ester,acrylonitrile......) Zeagler-Nattatypecatalyst-TiCl4/AlEt3

ProductionofprimaryorganicchemicalsaminoxidationofpropenetoacrylonitrileCH2=CH

CH3+NH3+1/2O2

CH2=CH

CN+3H2O

P-Mo-Bi,multi-componentcatalyst

Severalimportantappliedfiel6Severalimportantappliedfieldsofcatalysis

ProductionofprimaryorganicchemicalsaminoxidationofpropenetoacrylonitrileCH2=CH

CH3+NH3+1/2O2

CH2=CH

CN+3H2O

P-Mo-Bi,multi-componentcatalyst

OxidationofethylenetoaldehydeCH2=CH2+1/2O2

CH3CHO

PdCl2/CuCl2complexingcatalys

Severalimportantappliedfiel7Severalimportantappliedfieldsofcatalysis

ManufacturingfinechemicalsInwholepatentsinvolvingcatalysisissuedinJapan,thosedealingwithfinechemicalshadbeenincreasedbyaboutthreetimes,from7.1%to24.8%duringtheperiodof1975-1984.EnvironmentprotectionCatalystforautomobiletailgas.ConvertingNOxandCODesulfuratingcatalystforfluegas

Severalimportantappliedfiel8Mainresearchinterests

MechanismofcatalysisKineticsofcatalyzedreactionTherelationbetweencatalyticpropertiesandstructureofcatalystDevelopingnewcatalystsandnewcatalytictechniquesMainresearchinterestsMechan9Somefrontierresearchdirection

HeterogenelizationofhomogeneouscatalysisCatalysisinC1chemistry:convertingCO,CO2,andCH4toproductsofeconomicalimportanceFilm(membrance)catalysisBiologicalEnzymecatalysisPhotocatalysisandphotosynthesisComputeroptimizationincatalystdesignandpreparationSpecialistsystemPatternrecognitionArtificialintelligenceSomefrontierresearchdirecti10§1.2Conceptanddefinition

CatalysisTheconceptofcatalysisisamethodofcontrollingtherateanddirectionofachemicalreactionCatalystAcatalystisasubstancethatincreasestherateofreactiontowardstoequilibriumwithoutbeingappreciablyconsumedintheprocess.Catalystcannotchangetheultimateequilibriumdeterminedbythermodynamics.Itsroleisrestrictedtoacceleratingtherateofapproachingtoequilibrium.§1.2Conceptanddefinition11§1.2Conceptanddefinition

CatalyzedreactionThebasicconceptisthatacatalyzedreactioninvolvesthechemisorptionofoneormoreofthereactantsontothesurfaceofthecatalyst,rearrangementofthebondinganddesorptionoftheproduct.Ingeneral,catalystparticipatesincertainintermediatestepsofareactiontoalterthereactionpathwayandtolowertheactivationenergy,henceincreasesthereactionrateconstant.

§1.2Conceptanddefinition12

catalystsurfacereactantAintermediateM productP工业催化原理英文ppt课件13

Ea

M Ea’

P

A

14§1.2Conceptanddefinition

k=Aexp(-Ea/kT)whenEadecreases

khasgotincreased

Infewercases,catalystmayalsochangethemagnitudeofpre-exponentialfactor§1.2Conceptanddefinition15§1.3ClassificationofcatalysisBiologicalenzymecatalysis 2H2O2

2H2O+O2

enzyme

HomogeneouscatalysisCH3COOC2H5

C2H5OH+CH3COOH

H2SO4themostimportanthomogeneouscatalystissolubletransitionmetalcomplex§1.3Classificationofcatal16§1.3ClassificationofcatalysisHeterogeneouscatalysisSolidacidicandbasiccatalystCH3OH

gasoline ZSM-5zeolite,acidic2CH4+O2

C2H4+2H2O MgO,basicSupportedcatalystCH4+H2O

CO+3H2(syngas) Ni/Al2O3

Oxidecatalyst,insulatororsemiconductorCO+H2

CH3OH CuO/ZnO

MetalcatalystC6H6(Benzene)+3H2

C6H12(Cyclohexane)Ni§1.3Classificationofcatal17§1.4Activity,selectivityandlifetimeofcatalyst

Activityconversion XA=(nA0-nA)/nA0

100% nA0:initialquantityofreactant nA:residualreactantattheendofreaction

Space-timeyield(especialforsolidcatalyst) quantityofproductformedperunittime perunitvolumeofcatalyst Kmol/hr·m3 g/min·L§1.4Activity,selectivityan18§1.4Activity,selectivityandlifetimeofcatalyst

Selectivity

k1CH3CHO(P)+H2 Cu,250ºCC2H5OH(A)

k2C2H4(B)+H2O Al2O3,350ºC

selectivefactors=k1/k2selectivitysP=a/p

nP/

(nA0-nA)

100%orsP=nP/

(nP+nB)

100%herea=1andp=1 Stoichimetriccoefficient

Yieldy=a/p

nP/

nA0

100%y=XA

sP§1.4Activity,selectivityan19§1.4Example

Forthereactionofmethanoldehydrogentomethylaldehyde CH3OHHCHO+H2Ifthemethanolfeedrateis5.0kmol/hrandtheproductis3.8kmol/hraldehydewith0.7kmol/hrmethanolasresidualconversionXA

XA=(nA0-nA)/nA0

100% =(5.0-0.7)/5.0

100%=86.0%selectivitysP

sp=a/p

nP/

(nA0-nA)

100%=3.8

/

(5.0-0.7)100%=88.4%