Table Of ContentChemical Reaction Engineering
and Reactor Technology,
Second Edition
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CRC CHEMI NDUS
Chemical Reaction Engineering
and Reactor Technology,
Second Edition
Tapio O. Salmi, Jyri-Pekka Mikkola, Johan P. Wärnå
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Names: Salmi, Tapio, author. | Mikkola, Jyri-Pekka, author. | Warna, John, author.
Title: Chemical reaction engineering and reactor technology / Tapio Salmi, Jyri-Pekka Mikkola, John Warna.
Description: Second edition. | Boca Raton : Taylor & Francis, a CRC title, part of the Taylor & Francis imprint,
a member of the Taylor & Francis Group, the academic division of T&F Informa, plc, 2019.
Identifiers: LCCN 2019006669 | ISBN 9781138712508 (hardback : alk. paper)
Subjects: LCSH: Chemical reactions. | Chemical reactors.
Classification: LCC TP157 .S25 2019 | DDC 660/.2832—dc23
LC record available at https://lccn.loc.gov/2019006669
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Contents
Preface............................................................................................................................................xiii
Preface to Second Edition ................................................................................................................xv
Author Biography ...........................................................................................................................xvii
Notations .........................................................................................................................................xix
Dimensionless Groups .................................................................................................................xxiii
Greek Symbols ..............................................................................................................................xxiv
Subscripts and Superscripts ..........................................................................................................xxvi
Abbreviations ...............................................................................................................................xxvii
Chapter 1 Introduction ..................................................................................................................1
1.1 Preliminary Studies ...........................................................................................2
1.1.1 Reaction Stoichiometry, Thermodynamics, and Synthesis Routes ......2
1.2 Laboratory Experiments ....................................................................................2
1.3 Analysis of the Experimental Results ...............................................................2
1.4 Simulation of Reactor Models ...........................................................................2
1.5 Installation of a Pilot-Plant Unit ........................................................................4
1.6 Construction of the Facility in Full Scale .........................................................4
References ....................................................................................................................5
Chapter 2 Stoichiometry and Kinetics ..........................................................................................7
2.1 Stoichiometric Matrix........................................................................................7
2.2 Reaction Kinetics ..............................................................................................9
2.2.1 Elementary Reactions .........................................................................10
2.2.2 Kinetics of Nonelementary Reactions: Quasi-Steady-State
and Quasi-Equilibrium Approximations ............................................12
2.2.2.1 Ionic and Radical Intermediates .........................................15
2.2.2.2 Catalytic Processes: Eley–Rideal Mechanism ...................17
2.2.2.3 Catalytic Processes: Langmuir–Hinshelwood Mechanism......20
References ..................................................................................................................21
Chapter 3 Homogeneous Reactors ..............................................................................................23
3.1 Reactors for Homogeneous Reactions .............................................................23
3.2 Homogeneous Tube Reactor with a Plug Flow ................................................30
3.2.1 Mass Balance......................................................................................31
3.2.2 Energy Balance ..................................................................................32
3.3 Homogeneous Tank Reactor with Perfect Mixing ..........................................34
3.3.1 Mass Balance......................................................................................34
3.3.2 Energy Balance ..................................................................................35
3.4 Homogeneous BR ............................................................................................38
3.4.1 Mass Balance......................................................................................38
3.4.2 Energy Balance ..................................................................................39
3.5 Molar Amount, Mole Fraction, Reaction Extent, Conversion, and
Concentration ..................................................................................................41
3.5.1 Definitions ..........................................................................................41
v
vi Contents
3.5.2 Relation between Molar Amount, Extent of Reaction,
Conversion, and Molar Fraction .........................................................44
3.5.2.1 A System with a Single Chemical Reaction .......................44
3.5.2.2 A System with Multiple Chemical Reactions .....................46
3.5.3 Relationship between Concentration, Extent of Reaction,
Conversion, and Volumetric Flow Rate in a Continuous Reactor ......48
3.5.3.1 Gas-Phase Reactions ...........................................................48
3.5.3.2 Liquid-Phase Reactions ......................................................50
3.5.4 Relationship Between Concentration, Extent of Reaction,
Conversion, and Total Pressure in a BR .............................................51
3.5.4.1 Gas-Phase Reactions ...........................................................52
3.5.4.2 Liquid-Phase Reactions ......................................................53
3.6 Stoichiometry in Mass Balances .....................................................................54
3.7 Equilibrium Reactor: Adiabatic Temperature Change ....................................58
3.7.1 Mass and Energy Balances ................................................................58
3.8 Analytical Solutions for Mass and Energy Balances ......................................60
3.8.1 Multiple Reactions ..............................................................................61
3.8.1.1 First-Order Parallel Reactions ............................................64
3.8.1.2 Momentaneous and Integral Yield for Parallel Reactions ......68
3.8.1.3 Reactor Selection and Operating Conditions for
Parallel Reactions ...............................................................69
3.8.1.4 First-Order Consecutive Reactions .....................................71
3.8.1.5 Consecutive-Competitive Reactions ...................................75
3.8.1.6 Product Distributions in PFRs and BRs .............................76
3.8.1.7 Product Distribution in a CSTR .........................................78
3.8.1.8 Comparison of Ideal Reactors ............................................79
3.9 Numerical Solution of Mass Balances for Various Coupled Reactions ..........79
3.10 Semibatch Technology ....................................................................................82
3.10.1 Basic Semibatch Model ......................................................................82
3.10.2 Transition from Semibatch to Continuous Reactor ............................85
References ..................................................................................................................86
Chapter 4 Nonideal Reactors and Reactor Dynamics ................................................................89
4.1 Residence Time Distribution in Flow Reactors ...............................................89
4.1.1 Residence Time as a Concept .............................................................89
4.1.2 Methods for Determining RTDs ........................................................91
4.1.2.1 Volume Element ..................................................................91
4.1.2.2 Tracer Experiments .............................................................92
4.2 Residence Time Functions ...............................................................................92
4.2.1 Population Density Function E(t) .......................................................93
4.2.2 Distribution Functions F(t) and F*(t) .................................................95
4.2.3 Intensity Function λ(t) ........................................................................95
4.2.4 Mean Residence Time ........................................................................96
4.2.5 C Function ..........................................................................................96
4.2.6 Dimensionless Time ...........................................................................97
4.2.7 Variance..............................................................................................97
4.2.8 Experimental Determination of Residence Time Functions ..............97
4.2.9 RTD for a CSTR and PFR ................................................................101
4.2.10 RTD Intube Reactors with a Laminar Flow .....................................103
Contents vii
4.3 Segregation and Maximum Mixedness .........................................................106
4.3.1 Segregation Model ............................................................................107
4.3.2 Maximum Mixedness Model ...........................................................108
4.4 Tanks-in-Series Model ..................................................................................109
4.4.1 Residence Time Functions for the Tanks-in-Series Model ..............109
4.4.2 Tanks in Series as a Chemical Reactor ............................................112
4.4.3 Maximum Mixedness Tanks-in-Series Model .................................112
4.4.4 Segregated Tanks in Series ..............................................................113
4.4.5 Comparison of Tanks-in-Series Models ...........................................114
4.4.6 Existence of Micro- and Macrofluids ...............................................115
4.5 Axial Dispersion Model ................................................................................115
4.5.1 RTDs for the Axial Dispersion Model .............................................116
4.5.2 Axial Dispersion Model as a Chemical Reactor ..............................120
4.5.3 Estimation of the Axial Dispersion Coefficient ...............................122
4.6 Tube Reactor with a Laminar Flow ...............................................................125
4.6.1 Laminar Reactor Without Radial Diffusion ....................................125
4.6.2 Laminar Reactor with a Radial Diffusion: Axial
Dispersion Model .............................................................................128
4.7 Mixing and Mass Transfer in Tank Reactors ................................................129
4.7.1 Selection of Stirring System .............................................................130
4.7.2 Power Input .......................................................................................131
4.7.3 Experimental Investigation of Mixing in Closed Tanks ..................133
4.8 Isothermal Reactor Dynamics .......................................................................134
4.8.1 Transient Plug Flow and Axial Dispersion Models .........................136
4.8.2 Transient Model for Continuous Stirred Tank Reactor ....................137
4.8.2.1 Solution of Balance Equations in Time Frame .................138
4.9 Nonisothermal Reactor Dynamics ................................................................140
4.9.1 Energy Balance for an Infinitesimal Volume Element for Plug
Flow, Continuous Stirred Tank, and Batch Reactors .......................140
4.9.2 Dispersion of Heat in Tubular Reactors ...........................................144
4.9.3 Heat as a Tracer ................................................................................149
References ................................................................................................................150
Chapter 5 Catalytic Two-Phase Reactors ..................................................................................151
5.1 Reactors for Heterogeneous Catalytic Gas- and Liquid-Phase Reactions.....152
5.2 Packed Bed ....................................................................................................165
5.2.1 Mass Balances for the One-Dimensional Model .............................167
5.2.2 Effectiveness Factor .........................................................................169
5.2.2.1 Chemical Reaction and Diffusion inside a Catalyst
Particle ..............................................................................169
5.2.2.2 Spherical Particle ..............................................................174
5.2.2.3 Slab ...................................................................................177
5.2.2.4 Asymptotic Effectiveness Factors for Arbitrary Kinetics ......179
5.2.2.5 Nonisothermal Conditions ................................................184
5.2.3 Energy Balances for the One-Dimensional Model ..........................188
5.2.4 Mass and Energy Balances for the Two-Dimensional Model ..........192
5.2.5 Pressure Drop in Packed Beds .........................................................198
5.3 Fluidized Bed ................................................................................................200
5.3.1 Mass Balances According to Ideal Models ......................................202
viii Contents
5.3.2 Kunii–Levenspiel Model for Fluidized Beds ...................................204
5.3.2.1 Kunii–Levenspiel Parameters ...........................................207
5.4 Parameters for Packed Bed and Fluidized Bed Reactors ..............................211
5.5 Evaluation of Mass Transfer Effects in Heterogeneous Catalysis .................213
5.5.1 General Tests for Mass Transfer and Catalyst Activity ....................214
5.5.2 Test for External Mass Transfer Resistance .....................................215
5.5.3 Criteria for Internal Mass Transfer Resistance ................................216
References ................................................................................................................220
Chapter 6 Catalytic Three-Phase Reactors ...............................................................................223
6.1 Reactors Used for Catalytic Three-Phase Reactions .....................................223
6.2 Mass Balances For Three-Phase Reactors ....................................................232
6.2.1 Mass Transfer and Chemical Reaction .............................................233
6.2.2 Three-Phase Reactors with a Plug Flow ..........................................235
6.2.3 Three-Phase Reactor with Complete Backmixing ...........................237
6.2.4 Semibatch and Batch Reactors (BRs) ...............................................238
6.2.5 Parameters in Mass Balance Equations ...........................................239
6.3 Energy Balances for Three-Phase Reactors ..................................................240
6.3.1 Three-Phase PFR .............................................................................240
6.3.2 Tank Reactor with Complete Backmixing .......................................241
6.3.3 Batch Reactor ...................................................................................242
6.3.4 Analytical and Numerical Solutions of Balance Equations for
Three-Phase Reactors .......................................................................243
6.3.4.1 Sulfur Dioxide Oxidation .................................................243
6.3.4.2 Hydrogenation of Aromatics .............................................244
6.3.4.3 Carbonyl Group Hydrogenation .......................................246
References ................................................................................................................248
Chapter 7 Gas–Liquid Reactors ................................................................................................249
7.1 Reactors for Noncatalytic and Homogeneously Catalyzed Reactions ..........249
7.2 Mass Balances for Ideal Gas–Liquid Reactors .............................................256
7.2.1 Plug Flow Column Reactor ..............................................................258
7.2.2 Tank Reactor with Complete Backmixing .......................................261
7.2.3 Batch Reactor ...................................................................................262
7.2.4 Fluxes in Gas and Liquid Films .......................................................263
7.2.4.1 Very Slow Reactions .........................................................266
7.2.4.2 Slow Reactions ..................................................................268
7.2.4.3 Reactions with a Finite Velocity .......................................269
7.2.5 Fluxes in Reactor Mass Balances .....................................................281
7.2.6 Design of Absorption Columns ........................................................283
7.2.7 Gas and Liquid Film Coefficients, Diffusion Coefficients, and
Gas–Liquid Equilibria ......................................................................286
7.3 Energy Balances for Gas–Liquid Reactors ...................................................287
7.3.1 Plug Flow Column Reactor ..............................................................288
7.3.2 Tank Reactor with Complete Backmixing .......................................289
7.3.3 Batch Reactor ...................................................................................290
7.3.4 Coupling of Mass and Energy Balances ..........................................291
7.3.5 Numerical Solution of Gas–Liquid Reactor Balances .....................291
References ................................................................................................................293
Contents ix
Chapter 8 Reactors for Reactive Solids .....................................................................................295
8.1 Reactors for Processes with Reactive Solids .................................................295
8.2 Models for Reactive Solid Particles ...............................................................298
8.2.1 Definitions ........................................................................................298
8.2.2 Product Layer Model ........................................................................301
8.2.2.1 First-Order Reactions .......................................................305
8.2.2.2 General Reaction Kinetics: Diffusion Resistance as
the Rate-Determining Step ...............................................307
8.2.3 Shrinking Particle Model .................................................................307
8.2.3.1 First-Order Reactions .......................................................308
8.2.3.2 Arbitrary Reaction Kinetics: Diffusion Resistance in
the Gas Film as the Rate-Determining Step .....................311
8.3 Mass Balances for Reactors Containing a Solid Reactive Phase ..................311
8.3.1 Batch Reactor ...................................................................................311
8.3.1.1 Particles with a Porous Product Layer ..............................312
8.3.1.2 Shrinking Particles ...........................................................314
8.3.2 Semibatch Reactor ............................................................................316
8.3.2.1 Particle with a Porous Product Layer ...............................316
8.3.2.2 Shrinking Particle .............................................................317
8.3.3 Packed Bed .......................................................................................317
8.4 Models for Nonideal Solid Surfaces ..............................................................318
8.4.1 Product Layer Model for Nonideal Particles ....................................319
8.4.1.1 Diffusion through the Product Layer ................................320
8.4.1.2 Events at the Reaction Surface .........................................323
8.4.2 Shrinking Particle Model .................................................................324
8.4.2.1 Interaction of Chemical Reaction and Diffusion ..............324
8.4.3 Analytical Solution of the Models for Some Specific Kinetics .......325
8.4.3.1 Product Layer Model ........................................................325
8.4.3.2 Shrinking Particle Model .................................................326
8.4.3.3 Summary ..........................................................................326
8.4.4 Mass Transfer Parameters ................................................................326
8.4.4.1 Diffusion Coefficients .......................................................326
8.4.4.2 Fluid–Solid Mass Transfer Coefficients ...........................327
8.4.5 Reaction Area and Reaction Order with Respect to the Solid
Component .......................................................................................328
8.4.6 Batch Reactor Modeling ...................................................................330
References ................................................................................................................334
Chapter 9 Toward New Reactor and Reaction Engineering .....................................................335
9.1 How to Approach the Modeling of Novel Reactor Concepts? ......................335
9.2 Reactor Structures and Operation Modes .....................................................336
9.2.1 Reactors with Catalyst Packings ......................................................337
9.2.1.1 Mass Balances for the Gas and Liquid Bulk Phases ........338
9.2.1.2 Interfacial Transport .........................................................339
9.2.1.3 Mass Balances for the Catalyst Particles ..........................340
9.2.1.4 Numerical Solution of the Column Reactor Model ..........341
9.2.1.5 Concluding Summary .......................................................342
9.2.2 Monolith Reactors ............................................................................343
9.2.2.1 Flow Distribution from CFD Calculations .......................344
