Catalyst Design: Optimal Distribution of Catalyst in Pellets, Reactors, and Membranes (Cambridge Series in Chemical Engineering)

240 Pages·2005·2.998 MB·English

by  Massimo Morbidelli, Asterios Gavriilidis, Arvind Varma

Catalyst Design
Heterogeneouscatalysisiswidelyusedinchemical,refinery,andpollution-
controlprocesses.Forthisreason,achievingoptimalperformanceofcat-
alystsisasignificantissueforchemicalengineersandchemists.Thisbook
addresses the question of how catalytic material should be distributed
insideaporoussupportinordertoobtainoptimalperformance.Ittreats
single-andmultiple-reactionsystems,isothermalandnonisothermalcon-
ditions, pellets, monoliths, fixed-bed reactors, and membrane reactors.
Theeffectsofphysicochemicalandoperatingparametersareanalyzedto
gaininsightintotheunderlyingphenomenagoverningtheperformance
ofoptimallydesignedcatalysts.Throughout,theauthorsofferabalanced
treatmentoftheoryandexperiment.Particularattentionisgiventoprob-
lems of commercial importance. With its thorough treatment of the de-
sign, preparation, and utilization of supported catalysts, this book will
be a useful resource for graduate students, researchers, and practicing
engineersandchemists.
Massimo Morbidelli is Professor of Chemical Reaction Engineering in
theLaboratoriumfu¨rTechnischeChemieatETH,Zu¨rich.
Asterios Gavriilidis is Senior Lecturer in the Department of Chemical
EngineeringatUniversityCollegeLondon.
Arvind Varma is the Arthur J. Schmitt Professor in the Department of
ChemicalEngineeringattheUniversityofNotreDame.

CAMBRIDGE SERIES IN CHEMICAL ENGINEERING
SeriesEditor:
ArvindVarma,UniversityofNotreDame
EditorialBoard:
AlexisT.Bell,UniversityofCalifornia,Berkeley
JohnBridgwater,UniversityofCambridge
RobertA.Brown,MIT
L.GaryLeal,UniversityofCalifornia,SantaBarbara
MassimoMorbidelli,ETH,Zurich
StanleyI.Sandler,UniversityofDelaware
MichaelL.Shuler,CornellUniversity
ArthurW.Westerberg,CarnegieMellonUniversity
BooksintheSeries:
E.L.Cussler,Diffusion:MassTransferinFluidSystems,secondedition
Liang-ShihFanandChaoZhu,PrinciplesofGas-SolidFlows
HasanOrbeyandStanleyI.Sandler,ModelingVapor-LiquidEquilibria:
CubicEquationsofStateandTheirMixingRules
T.MichaelDuncanandJeffreyA.Reimer,ChemicalEngineeringDesign
andAnalysis:AnIntroduction
A.Varma,M.MorbidelliandH.Wu,ParametricSensitivityinChemical
Systems
JohnC.Slattery,AdvancedTransportPhenomena
M. Morbidelli, A. Gavriilidis and A. Varma, Catalyst Design: Optimal
DistributionofCatalystinPellets,Reactors,andMembranes

Catalyst Design
OPTIMAL DISTRIBUTION OF CATALYST IN
PELLETS, REACTORS, AND MEMBRANES
Massimo Morbidelli
ETH,Zurich
Asterios Gavriilidis
UniversityCollegeLondon
Arvind Varma
UniversityofNotreDame
To our teachers and students
CAMBRIDGE UNIVERSITY PRESS
Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, São Paulo
Cambridge University Press
The Edinburgh Building, Cambridge CB2 2RU, UK
Published in the United States of America by Cambridge University Press, New York
www.cambridge.org
Information on this title: www.cambridge.org/9780521660594
© Cambridge University Press 2001
This publication is in copyright. Subject to statutory exception
and to the provisions of relevant collective licensing agreements,
no reproduction of any part may take place without
the written permission of Cambridge University Press.
First published 2001
This digitally printed first paperback version 2005
A catalogue record for this publication is available from the British Library
Library of Congress Cataloguing in Publication data
Morbidelli, Massimo.
Catalyst design : optimal distribution of catalyst in pellets, reactors, and membranes /
Massimo Morbidelli, Asterios Gavriilidis, Arvind Varma.
p. cm. – (Cambridge series in chemical engineering)
Includes bibliographical references.
ISBN 0-521-66059-9
1. Catalysts. I. Gavriilidis, Asterios, 1965– II. Varma, Arvind. III. Title. IV. Series.
TP159.C3 M62 2001
660´.2995 – dc21 00-041460
ISBN-13 978-0-521-66059-4 hardback
ISBN-10 0-521-66059-9 hardback
ISBN-13 978-0-521-01985-9 paperback
ISBN-10 0-521-01985-0 paperback
Contents
Preface page xiii
1 Introduction 1
1.1 ImportanceofCatalysis 1
1.2 NonuniformCatalystDistributions 1
1.3 OverviewofBookContents 4
2 Optimization of the Catalyst Distribution in a Single Pellet 6
2.1 TheCaseofaSingleReaction 6
2.1.1 IsothermalConditions 6
2.1.2 NonisothermalConditions 15
2.1.3 ArbitraryKineticswithExternalTransportResistances 18
2.1.4 DynamicBehavior 23
2.2 MultipleReactions 25
2.2.1 IsothermalConditions 25
2.2.2 NonisothermalConditions 28
2.3 TheGeneralCaseofaComplexReactionSystem 30
2.3.1 AnIllustrativeExample 31
2.3.2 GeneralReactionSystem 35
2.4 CatalystDispersionConsiderations 40
2.4.1 FactorsAffectingCatalystDispersion 40
2.4.2 DependenceofCatalyticSurfaceAreaonCatalystLoading 43
2.5 OptimalDistributionofCatalystLoading 46
2.5.1 TheProblemFormulation 47
2.5.2 ASingleFirst-OrderIsothermalReaction 51
2.5.3 LinearDependencebetweentheActiveElementSurface
AreaandItsLoading 54
2.5.4 First-OrderNonisothermalReactions:NumericalOptimization 55
2.5.5 MultistepOptimalLoadingDistribution 59
2.6 ExperimentalStudies 63
2.6.1 OxidationReactions 63
2.6.2 HydrogenationReactions 66
2.6.3 Fischer–TropschSynthesis 68
vii
viii Contents
3 Optimization of the Catalyst Distribution in a Reactor 69
3.1 ASingleReaction 69
3.1.1 IsothermalConditions 69
3.1.2 NonisothermalConditions 75
3.2 MultipleReactions 77
3.2.1 IsothermalConditions 77
3.2.2 NonisothermalConditions 79
3.3 ExperimentalStudies 83
3.3.1 PropaneandCOOxidation 83
3.3.2 CatalyticIncinerationofVolatileOrganicCompounds 85
4 Studies Involving Catalyst Deactivation 86
4.1 NonselectivePoisoning 86
4.2 SelectivePoisoning 89
4.3 ExperimentalStudies 91
4.3.1 Methanation 91
4.3.2 Hydrogenation 92
4.3.3 NOReduction 94
5 Membrane Reactors 95
5.1 MembraneReactorswithNonuniformCatalystDistribution 95
5.2 OptimalCatalystDistributioninPelletsforan
InertMembraneReactor 100
5.3 OptimalCatalystDistributioninaCatalyticMembraneReactor 100
5.4 ExperimentalStudies 102
5.4.1 DehydrogenationReactions 102
5.4.2 PreparationofCatalyticMembranes 105
6 Special Topics of Commercial Importance 110
6.1 AutomotiveExhaustCatalysts 110
6.1.1 DesignofLayeredCatalysts 111
6.1.2 NonuniformAxialCatalystDistribution 113
6.2 HydrotreatingCatalysts 115
6.3 CompositeZeoliteCatalysts 119
6.4 ImmobilizedBiocatalysts 121
6.5 FunctionalizedPolymerResins 124
6.5.1 PreparationofNonuniformlyFunctionalizedResinParticles 124
6.5.2 ApplicationstoReactingSystems 126
7 Preparation of Pellets with Nonuniform Distribution of Catalyst 131
7.1 AdsorptiononPowders 132
7.1.1 AdsorptionIsothermModels 132
7.1.2 EffectofImpregnationVariablesonAdsorption 135
7.1.2.a SolutionpHandNatureofSupport 135
7.1.2.b SurfaceHeterogeneity 138
7.1.2.c IonicStrength 140
7.1.2.d PrecursorSpeciation 140
7.1.2.e Coimpregnants 142
7.1.2.f NatureoftheSolvent 144
7.1.3 SurfaceIonizationModels 144
7.1.3.a Constant-CapacitanceModel 145
Contents ix
7.1.3.b Diffuse-LayerModel 146
7.1.3.c BasicSternModel 147
7.1.3.d Triple-LayerModel 147
7.1.3.e Four-Layermodel 149
7.2 SimultaneousDiffusionandAdsorptioninPellets 149
7.2.1 TheoreticalStudies 150
7.2.1.a DryImpregnation 150
7.2.1.b WetImpregnation 153
7.2.1.c EffectsofElectrokineticandIonicDissociationPhenomena 156
7.2.1.d EffectofDryingConditions 156
7.2.2 ExperimentalStudies 158
7.2.2.a Single-ComponentImpregnation 159
7.2.2.b MulticomponentImpregnation 161
7.2.2.c EffectsofDrying 165
7.2.2.d DeterminationofCatalystDistribution 169
7.2.3 ComparisonofModelCalculationswithExperimentalStudies 169
7.2.3.a DryImpregnation 169
7.2.3.b WetImpregnation 171
AppendixA:ApplicationoftheMaximumPrincipleforOptimization
ofaCatalystDistribution 181
AppendixB:OptimalCatalystDistributioninPelletsforanInert
MembraneReactor:ProblemFormulation 188
B.1 TheMassandEnergyBalanceEquations 188
B.2 ThePerformanceIndexes 191
B.3 DevelopmentoftheHamiltonian 192
Notation 195
References 201
AuthorIndex 221
SubjectIndex 225