Mass Transfer and Separation Processes

Transcription

1

2 Principles of Mass Transfer and Separation Processes Binay K. Dutta Universiti Teknologi Petronas Malaysia New Delhi

3 PRINCIPLES OF MASS TRANSFER AND SEPARATION PROCESSES Binay K. Dutta 2007 by PHI Learning Private Limited, New Delhi. All rights reserved. No part of this book may be reproduced in any form, by mimeograph or any other means, without permission in writing from the publisher. Cover photo Courtesy: Haldia Petrochemicals Limited ISBN The export rights of this book are vested solely with the publisher. Third Printing º º º November, 2009 Published by Asoke K. Ghosh, PHI Learning Private Limited, M-97, Connaught Circus, New Delhi and Printed by Rajkamal Electric Press, Plot No. 2, Phase IV, HSIDC, Kundli , Sonepat, Haryana.

4 To the memory of My parents Gouri Dutta and Baneswar Dutta and My father-in-law Debabrata Majumder

5

6 Contents Preface xi 1. INTRODUCTION 1 6 References 6 2. MOLECULAR DIFFUSION Concentration, Velocity and Flux Fick s Law Steady State Molecular Diffusion through a Constant Area in a Binary Gas Mixture Multicomponent Diffusion Gas-Phase Diffusion Coefficient: Measurement and Prediction Molecular Diffusion in Liquids Diffusion through a Variable Area Knudsen Diffusion, Surface Diffusion and Self-Diffusion Applications of the Principles of Molecular Diffusion 59 Notations 59 Short and Multiple Choice Questions 60 Problems 64 References CONVECTIVE MASS TRANSFER AND MASS TRANSFER COEFFICIENT The Mass Transfer Coefficient Types of Mass Transfer Coefficients Dimensionless Groups in Mass Transfer Correlations for the Convective Mass Transfer Coefficient Turbulent or Eddy Diffusion The Wetted-Wall Column Theories of Mass Transfer Momentum, Heat and Mass Transfer Analogies 102 v

7 vi Contents Notations 106 Short and Multiple Choice Questions 107 Problems 111 References INTERPHASE MASS TRANSFER Equilibrium between Phases The Raoult s and the Henry s law Mass Transfer between Two Phases The Overall Mass Transfer Coefficient Material Balance in a Contacting Equipment the Operating Line Mass Transfer in Stage-wise Contact of two Phases Interphase Mass Transfer in Drug Delivery Systems Applications 158 Notations 159 Short and Multiple Choice Questions 160 Problems 163 References GAS LIQUID CONTACTING EQUIPMENT Introduction to Gas Liquid Contacting Tray or Plate Column Operational Features of a Tray Column A Few Mechanical Details Tray Design High Capacity Trays Agitated Vessels The Bubble Column The Spray Tower The Venturi Scrubber The Packed Tower Flooding in a Packed Tower Theoretical Models of Flow through a Packed Tower Comparison between Packed and Plate Towers 241 Notations 243 Multiple Choice Questions 244 Short Questions 251 Problems 252 References GAS ABSORPTION AND STRIPPING Equilibrium in a Gas Liquid System Selection of Solvent and Stripping Medium Minimum Liquid Rate for Absorption Design of a Packed Tower Correlations for Mass Transfer Coefficients in Packed Towers 281

8 Contents vii 6.6 Determination of the Number of Stages in a Tray Tower Height Equivalent to a Theoretical Plate (HETP) Tray Efficiency Other Applications of Gas Absorption and Stripping 300 Notations 302 Short and Multiple Choice Questions 303 Problems 310 References DISTILLATION Vapour Liquid Equilibrium Enthalpy Concentration Diagram Flash Vaporization Steam Distillation Batch Distillation Continuous Multistage Fractionation of Binary Mixtures Multistage Batch Distillation with Reflux The Ponchon Savarit Method Distillation in a Packed Tower 401 Notations 405 Short and Multiple Choice Questions 407 Problems 411 References LIQUID LIQUID EXTRACTION A Few Examples of Solvent Extraction Liquid Liquid Equilibria (LLE) Solvent Selection Design Calculations for Stage-Wise Extraction Liquid Liquid Extraction Equipment Selection of Extractors Hydrodynamics and Mass Transfer in a Stirred Liquid Liquid Dispersion Extraction Equipment Design 467 Notations 468 Short and Multiple Choice Questions 469 Problems 472 References SOLID LIQUID EXTRACTION Classification of Solid Liquid Extraction Systems The Rate of Solid Liquid Extraction Solid Liquid Contacting Strategy Solid Liquid Contacting Equipment Solid Liquid Extraction Equilibrium 487

9 viii Contents 9.6 Solid Liquid Extraction Calculations Supercritical Fluid Extraction 499 Notations 501 Short and Multiple Choice Questions 502 Problems 504 References HUMIDIFICATION AND WATER COOLING Terminology and Definitions Adiabatic Saturation Temperature Wet-Bulb Temperature The Psychrometric Chart and Its Use Description of Cooling Towers Construction and Operation Cooling Tower Calculations Some Additional Information on Cooling Towers 540 Notations 541 Short and Multiple Choice Questions 542 Problems 547 References DRYING OF WET SOLIDS Physical Mechanism of Drying Drying Equilibria Important Definitions and Terms The Drying Rate Curve Calculation of the Drying Time from the Drying Rate Data Classification of Drying Equipment Direct-Heat Batch Dryers: Tray and Truck Dryers Direct-Heat Continuous Dryers Indirect-Heat Batch Systems Indirect-Heat Continuous Dryers Air-Suspended Drying Systems Drying Calculations Preliminary Design of a Rotary Dryer Freeze Drying Calculations Dryer Selection 597 Notations 597 Short and Multiple Choice Questions 598 Problems 603 References ADSORPTION Commercial Adsorbents and Their Applications Characteristics and Properties of Adsorbents Adsorption Equilibria Heat of Adsorption 623

10 Contents ix 12.5 Specific Surface Area of an Adsorbent Selection of Adsorbents Batch Adsorption in a Stirred Vessel Adsorption in a Fixed Bed Adsorption Equipment Adsorption Dynamics Thermal Regeneration of Adsorbents Pressure Swing Adsorption Ion-Exchange Chromatography 660 Notations 666 Short and Multiple Choice Questions 667 Problems 670 References CRYSTALLIZATION Solid Liquid Phase Equilibrium Nucleation and Crystal Growth Crystal Growth Crystal Size Distribution Characteristics of Crystal Size Distribution Batch Crystallization Crystallization Equipment Design Considerations Melt Crystallization 718 Notations 718 Short and Multiple Choice Questions 719 Problems 722 References MEMBRANE SEPARATION Materials, Types and Preparation of Membranes Membrane Characterization Membrane Modules Pressure-Driven Membrane Processes for Liquid Separation Concentration-Driven Processes Membrane Gas Separation 789 Notations 808 Short and Multiple Choice Questions 809 Problems 814 References MULTICOMPONENT DISTILLATION Degrees of Freedom in Multicomponent Distillation Key Components Column Operating Conditions 827

11 Principles Of Mass Transfer And Separation Processes 25% OFF Publisher : PHI Learning ISBN : Author : DUTTA, BINAY K. Type the URL : 06 Get this ebook