Separation Process Engineering
Second Edition
Formerly published as Equilibrium Staged Separations
PHILLIP C. WANKAT
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Library of Congress Cataloging-in-Publication Data
Wankat, Phillip C., 1944-
Separation process engineering / Phillip C. Wankat.—2nd ed.
p. cm.
Rev. ed. of: Equilibrium staged separations. c1988.
Includes bibliographical references and index.
ISBN 0 13 084789 5 (alk. paper)
1. Separation (Technology) I. Wankat, Phillip C., 1944–Equilibrium staged separations. II. Title.
TP156.S45W36 2007
660’.2842—dc22 2006009999
Copyright © 2007 Pearson Education, Inc.
All rights reserved. Printed in the United States of America. This publication is protected by copyright, and permission must be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permissions, write to:
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ISBN 0–13–084789–5
Text printed in the United States on recycled paper at Courier in Westford, Massachusetts.
Eighth printing, December 2010
Contents
Chapter 1 Introduction to Separation Process Engineering
1.1. Importance of Separations
1.6. Other Resources on Separation Process Engineering
2.1. Basic Method of Flash Distillation
2.2. Form and Sources of Equilibrium Data
2.3. Graphical Representation of Binary VLE
2.4. Binary Flash Distillation
2.4.1. Sequential Solution Procedure
Example 2-1. Flash separator for ethanol and water
2.4.2. Simultaneous Solution Procedure
2.6. Multicomponent Flash Distillation
Example 2-2. Multicomponent flash distillation
2.7. Simultaneous Multicomponent Convergence
Example 2-3. Simultaneous convergence for flash distillation
Example 2-4. Calculation of drum size
2.9. Utilizing Existing Flash Drums
Appendix Computer Simulation of Flash Distillation
Chapter 3 Introduction to Column Distillation
3.1. Developing a Distillation Cascade
Example 3-1. External balances for binary distillation
Chapter 4 Column Distillation: Internal Stage-by-Stage Balances
4.2. Binary Stage-by-Stage Solution Methods
Example 4-1. Stage-by-stage calculations by the Lewis method
4.3. Introduction to the McCabe-Thiele Method
Example 4-2. Feed line calculations
4.5. Complete McCabe-Thiele Method
Example 4-3. McCabe-Thiele method
4.6. Profiles for Binary Distillation
Example 4-4. McCabe-Thiele analysis of open steam heating
4.8. General McCabe-Thiele Analysis Procedure
Example 4-5. Distillation with two feeds
4.9. Other Distillation Column Situations
4.9.3. Side Streams or Withdrawal Lines
4.9.4. Intermediate Reboilers and Intermediate Condensers
4.9.5. Stripping and Enriching Columns
4.10. Limiting Operating Conditions
4.13. New Uses for Old Columns
4.14. Subcooled Reflux and Superheated Boilup
4.15. Comparisons between Analytical and Graphical Methods
Appendix Computer Simulations for Binary Distillation
Chapter 5 Introduction to Multicomponent Distillation
5.1. Calculational Difficulties
Example 5-1. External mass balances using fractional recoveries
5.2. Profiles for Multicomponent Distillation
Chapter 6 Exact Calculation Procedures for Multicomponent Distillation
6.1. Introduction to Matrix Solution for Multicomponent Distillation
6.2. Component Mass Balances in Matrix Form
6.3. Initial Guess for Flow Rates
6.4. Bubble-Point Calculations
Example 6-1. Bubble-point temperature
Example 6-2. Matrix calculation and è-convergence
6.6. Energy Balances in Matrix Form
Appendix Computer Simulations for Multicomponent Column Distillation
Chapter 7 Approximate Shortcut Methods for Multicomponent Distillation
7.1. Total Reflux: Fenske Equation
7.2. Minimum Reflux: Underwood Equations
Example 7-2. Underwood equations
7.3. Gilliland Correlation for Number of Stages at Finite Reflux Ratio
Example 7-3. Gilliland correlation
Chapter 8 Introduction to Complex Distillation Methods
8.1. Breaking Azeotropes with Other Separators
8.2. Binary Heterogeneous Azeotropic Distillation Processes
8.2.1. Binary Heterogeneous Azeotropes
8.2.2. Drying Organic Compounds That Are Partially Miscible with Water
Example 8-1. Drying benzene by distillation
Example 8-2. Steam distillation.
8.4 Two-Pressure Distillation Processes
8.5 Complex Ternary Distillation Systems
8.7 Azeotropic Distillation with Added Solvent
8.8 Distillation with Chemical Reaction
Appendix Simulation of Complex Distillation Systems
9.1 Binary Batch Distillation: Rayleigh Equation
9.2 Simple Binary Batch Distillation
Example 9-1. Simple Rayleigh distillation
9.3 Constant-Level Batch Distillation
9.5 Multistage Batch Distillation
Example 9-2. Multistage batch distillation
Chapter 10 Staged and Packed Column Design
10.1 Staged Column Equipment Description
10.1.1 Trays, Downcomers, and Weirs
Example 10-1. Overall efficiency estimation
10.3 Column Diameter Calculations
Example 10-2. Diameter calculation for tray column
10.4 Sieve Tray Layout and Tray Hydraulics
Example 10-3. Tray layout and hydraulics
10.6 Introduction to Packed Column Design
10.8 Height of Packing: HETP Method
10.9 Packed Column Flooding and Diameter Calculation
Example 10-4. Packed column diameter calculation
Chapter 11 Economics and Energy Conservation in Distillation
11.2 Operating Effects on Costs
Example 11-1. Cost estimate for distillation
11.3 Changes in Plant Operating Rates
11.4 Energy Conservation in Distillation
11.5 Synthesis of Column Sequences for Almost Ideal Multicomponent Distillation
Example 11-2. Sequencing columns with heuristics
11.6 Synthesis of Distillation Systems for Nonideal Ternary Systems
Example 11-3. Process development for separation of complex ternary mixture
Chapter 12 Absorption and Stripping
12.1 Absorption and Stripping Equilibria
12.2 Operating Lines for Absorption
Example 12-1. Graphical absorption analysis
12.5 Analytical Solution: Kremser Equation
Example 12-2. Stripping analysis with Kremser equation
12.6 Dilute Multisolute Absorbers and Strippers
12.7 Matrix Solution for Concentrated Absorbers and Strippers
Appendix Computer Simulations for Absorption and Stripping
Chapter 13 Immiscible Extraction, Washing, Leaching, and Supercritical Extraction
13.1 Extraction Processes and Equipment
13.2 Countercurrent Extraction
13.2.1. McCabe-Thiele Method for Dilute Systems
Example 13-1. Dilute countercurrent immiscible extraction
13.2.2. Kremser Method for Dilute Systems
13.3 Dilute Fractional Extraction
13.4 Single-Stage and Cross-Flow Extraction
Example 13-2. Single-stage and cross-flow extraction of a protein
13.5 Concentrated Immiscible Extraction
13.7 Generalized McCabe-Thiele and Kremser Procedures
13.10 Supercritical Fluid Extraction
13.11 Application to Other Separations
Chapter 14 Extraction of Partially Miscible Systems
14.2 Mixing Calculations and the Lever-Arm Rule
14.3 Single-Stage and Cross-Flow Systems
Example 14-1. Single-stage extraction
14.4 Countercurrent Extraction Cascades
14.4.1. External Mass Balances
14.4.2. Difference Points and Stage-by-Stage Calculations
14.4.3. Complete Extraction Problem
Example 14-2. Countercurrent extraction
14.5 Relationship between McCabe-Thiele and Triangular Diagrams
14.7 Extraction Computer Simulations
14.8 Leaching with Variable Flow Rates
Example 14-3. Leaching calculations
Appendix Computer Simulation of Extraction
Chapter 15 Mass Transfer Analysis
15.2 HTU-NTU Analysis of Packed Distillation Columns
Example 15-1. Distillation in a packed column
15.3 Relationship of HETP and HTU
15.4 Mass Transfer Correlations for Packed Towers
15.4.1. Detailed Correlations for Random Packings
Example 15-2. Estimation of HG and HL
15.5 HTU-NTU Analysis of Absorbers and Strippers
Example 15-3. Absorption of SO2
15.6 HTU-NTU Analysis of Co-current Absorbers
Example 15-4. Estimation of stage efficiency
Chapter 16 Introduction to Membrane Separation Processes
16.1 Membrane Separation Equipment
16.3.1. Gas Permeation of Binary Mixtures
16.3.2. Binary Permeation in Perfectly Mixed Systems
Example 16-1. Well-mixed gas permeation—sequential, analytical solution
Example 16-2. Well-mixed gas permeation—simultaneous analytical and graphical solutions
16.3.3. Multicomponent Permeation in Perfectly Mixed Systems
Example 16-3. Multicomponent, perfectly mixed gas permeation
16.4.1. Analysis of Osmosis and Reverse Osmosis
Example 16-4. RO without concentration polarization
16.4.2. Determination of Membrane Properties from Experiments
Example 16-5. Determination of RO membrane properties
16.4.3. Determination of Concentration Polarization
Example 16-6. RO with concentration polarization
Example 16-7. Prediction of RO performance with concentration polarization
16.4.4. RO with Concentrated Solutions
Example 16-8. UF with gel formation
Example 16-9. Pervaporation: feasibility calculation
Example 16-10. Pervaporation: development of feasible design
16.7 Bulk Flow Pattern Effects
Example 16-11. Flow pattern effects in gas permeation
16.7.1. Binary Cross-Flow Permeation
16.7.2. Binary Co-current Permeation
16.7.3. Binary Countercurrent Flow
Appendix Spreadsheets for Flow Pattern Calculations for Gas Permeation
Chapter 17 Introduction to Adsorption, Chromatography, and Ion Exchange
17.1 Sorbents and Sorption Equilibrium
17.1.3. Adsorption Equilibrium Behavior
Example 17-1. Adsorption equilibrium
17.2 Solute Movement Analysis for Linear Systems: Basics and Applications to Chromatography
17.2.1. Movement of Solute in a Column
17.2.2. Solute Movement Theory for Linear Isotherms
17.2.3. Application of Linear Solute Movement Theory to Purge Cycles and Elution Chromatography
Example 17-2. Linear solute movement analysis of elution chromatography
17.3 Solute Movement Analysis for Linear Systems: Thermal and Pressure Swing Adsorption and Simulated Moving Beds
17.3.1. Temperature Swing Adsorption
Example 17-3. Thermal regeneration with linear isotherm
17.3.2. Pressure Swing Adsorption
17.4 Nonlinear Solute Movement Analysis
Example 17-7. Self-sharpening shock wave
17.5.1. Ion Exchange Equilibrium
Example 17-8. Ion movement for divalent-monovalent exchange
17.6.1. Mass Transfer and Diffusion
17.6.3. Lumped Parameter Mass Transfer
17.6.4. Energy Balances and Heat Transfer
17.6.5. Derivation of Solute Movement Theory
17.7 Mass Transfer Solutions for Linear Systems
17.7.1. Lapidus and Amundson Solution for Local Equilibrium with Dispersion
17.7.2. Superposition in Linear Systems
Example 17-9. Lapidus and Amundson solution for elution
17.8 LUB Approach for Nonlinear Systems
17.9 Checklist for Practical Design and Operation
Appendix Introduction to the Aspen Chromatography Simulator
Appendix A. Aspen Plus Troubleshooting Guide for Separations