Mass Transfer: Principles and Applications

In recent years, the subject of mass transfer has been treated as a minor player in the larger field of transport phenomena and taken a back seat to its more mature "brother," heat transfer. Yet mass transfer is sufficiently mature as a discipline and sufficiently distinct from other transport processes to merit a separate treatment, particularly one that does not overwhelm readers with an abundance of high-level mathematics. Mass Transfer: Principles and Applications takes an integrated approach that uses a wealth of real-world examples, organizes the material according to mode of operation, and highlights the importance of modeling. The author begins by introducing diffusion rates, Fick's Law, film theory, and mass transfer coefficients, then develops these concepts in complementary stages. The treatment of phase equilibria covers topics generally not addressed in thermodynamics courses, and these concepts are then used to analyze compartmental models and staged processes as well as continuous contact operations. The final chapter offers a concise survey of simultaneous mass and heat transfer. Throughout the book, discussions transition smoothly between theory and practice and clearly reflect the author's many years of engineering experience and the breadth of mass transfer applications. Mass Transfer: Principles and Applications is a unique and accessible treatment of this relatively complicated topic that will fill a significant gap as both a textbook and professional reference.

SOME BASIC NOTIONS: RATES OF MASS TRANSFER
Gradient-Driven Transport
Illustrations: Transport in Systems with Vanishing Gradients, Diffusion through a Hollow Cylinder , Underground Storage of Helium: Diffusion
Transport Driven by a Potential Difference: The Film Concept and the Mass Transfer Coefficient
Units of the Potential and of the Mass Transfer Coefficient
Illustration: Conversion of Mass Transfer Coefficients
Equimolar Counterdiffusion and Diffusion through a Stagnant Film: The Log-Mean Concentration Difference
Illustration:Estimation of Mass Transfer Coefficients and Film Thickness. Transport in Blood Vessels
The Two-Film Theory
Overall Driving Forces and Mass Transfer Coefficients
Illustrations:Qualitative Analysis of Concentration Profiles and Mass Transfer, Drying with an Air Blower: A Fermi Problem
Conclusion
Practice Problems

MODELING MASS TRANSPORT: THE MASS BALANCES
The Compartment and the One-Dimensional Pipe
Illustration: Evaporation of a Solute to the Atmosphere, Reaeration of a River
The Classification of Mass Balances
Illustrations: The Countercurrent Gas Scrubber: Genesis of Steady Integral and Differential Mass Balances , Two Examples from Biology: The Quasi-Steady-State Assumption , Batch Distillation: An Example of a Cumulative Balance
The Information Obtained from Model Solutions
Setting Up Partial Differential Equations
Illustrations: Unsteady Diffusion in One Direction: Fick's Equation, Laminar Flow and Diffusion in a Pipe: The Graetz Problem for Mass Transfer , A Metallurgical Problem: Microsegregation in the Casting of Alloys and How to Avoid PDEs
The General Conservation Equations
Illustrations: Laplace's Equation, Steady-State Diffusion in Three-Dimensional Space: Emissions from Embedded Sources, Lifetime of Volatile Underground Deposits
Practice Problems

DIFFUSION THROUGH GASES, LIQUIDS, AND SOLIDS
Diffusion Coefficients
Illustrations: Diffusivity of Cadmium Vapor in Air , Electrorefining of Metals. Concentration, Polarization and the Limiting Current Density, Uptake and Permeation of Atmospheric Oxygen in PVC, Sievert's Law: Hydrogen Leakage through a Reactor Wall, The Design of Packaging Materials, Transpiration of Water from Leaves. Photosynthesis and Its Implications for Global Warming, Diffusivity in a Catalyst Pellet, Diffusivity of a Dopant in a Silicon Chip
Practice Problems

MORE ABOUT DIFFUSION: TRANSIENT DIFFUSION AND DIFFUSION WITH REACTION
Transient Diffusion
Illustrations: Concentration Response to an Instantaneous Point Source: Release in the Environment and in a Living Cell, Net Rate of Global Carbon Dioxide Emissions, Finding a Solution in a Related Discipline: The Effect of Wind on the Dispersion of Emissions, Penetration of a Solute into a Semi-Infinite Domain, Cumulative Uptake by Diffusion for the Semi-Infinite Domain, Manufacture of Transformer Steel, Determination of Diffusivity in Animal Tissue, Extraction of Oil from Vegetable Seeds
Diffusion and Reaction
Illustrations: Reaction and Diffusion in a Catalyst Particle. The Effectiveness Factor and the Design of Catalyst Pellets , A Moving Boundary Problem: The Shrinking Core Model, First-Order Reaction with Diffusion in a Liquid Film: Selection of a Reaction Solvent
Practice Problems

A SURVEY OF MASS TRANSFER COEFFICIENTS
Dimensionless Groups
Illustration: The Wall-Sherwood Number
Mass Transfer Coefficients in Laminar Flow: Extraction from the PDE Model
Illustration: Release of a Solute into Tubular Laminar Flow: Transport in the Entry Region
Mass Transfer in Turbulent Flow: Dimensional Analysis and the Buckingham p Theorem
Illustrations: Derivation of a Correlation for Turbulent Flow Mass Transfer Coefficients Using DimensionalAnalysis , Estimation of the Mass Transfer Coefficient kY for the Drying of Plastic Sheets
Mass Transfer Coefficients for Tower Packings
Illustrations: Prediction of the Volumetric Mass Transfer Coefficient of a Packing
Mass Transfer Coefficients in Agitated Vessels
Illustrations: Dissolution of Granular Solids in an Agitated Vessel
Mass Transfer Coefficients in the Environment: Uptake and Clearance of Toxic Substances in Animals: The Bioconcentration Factor
Illustration: Uptake and Depuration of Toxins: Approach to Steady State and Clearance Half-Lives
Practice Problems

PHASE EQUILIBRIA
Single-Component Systems: Vapor Pressure
Illustration: Maximum Breathing Losses from a Storage Tank
Multicomponent Systems: Distribution of a Single Component
Illustrations: Carbonation of a Soft Drink, Discharge of Plant Effluent into a River , Adsorption of Benzene from Water in a Granular Carbon Bed , Adsorption of a Pollutant from Groundwater onto Soil, The Mixture or Lever Rule in the Triangular Diagram, Decaffeination in a Single-Equilibrium Stage, The Octanol-Water Partition Coefficient
Multicomponent Equilibria: Distribution of Several Components
Illustrations: Application of the Phase Rule, The Effect of Total Pressure on alpha , Activity Coefficients from Solubilities
Practice Problems

STAGED OPERATIONS: THE EQUILIBRIUM STAGE
Equilibrium Stages
Illustrations: Single-Stage Adsorption: The Rectangular Operating Diagram, Single-Stage Liquid Extraction: The Triangular Operating Diagram, Differential Distillation: The Rayleigh Equation , Rayleigh's Equation in the Environment: Attenuation of Mercury Pollution in a Water Basin, Optimum Use of Adsorbent or Solvent in Crosscurrent Cascades, A Crosscurrent Extraction Cascade in Triangular Coordinates, Comparison of Various Stage Configurations: The Kremser-Souders-Brown Equation, Design of a Distillation Column in the McCabe-Thiele Diagram, Isotope Distillation: The Fenske Equation, Batch-Column Distillation: Model Equations and Some Simple Algebraic Calculations, Contamination and Clearance of Soils and River Beds
Stage Efficiencies
Illustrations: Stage Efficiencies of Liquid Solid Systems, Efficiency of an Adsorption or Ion-Exchange Column
Practice Problems

CONTINUOUS-CONTACT OPERATIONS
Packed-Column Operations
Illustrations: The Countercurrent Gas Scrubber Revisited, The Countercurrent Gas Scrubber Again: Analysis of the Linear Case, Distillation in a Packed Column: The Case of Constant a at Total Reflux, Coffee Decaffeination by Countercurrent Supercritical Fluid Extraction
Membrane Processes
Illustrations: Brian's Equation for Concentration Polarization, A Simple Model of Reverse Osmosis, Modeling the Artificial Kidney: Analogy to the External Heat Exchanger, Membrane Gas Separation: Selectivity a and the Pressure Ratio f
Practice Problems

SIMULTANEOUS HEAT AND MASS TRANSFER
The Air-Water System: Humidification and Dehumidification,
Evaporative Cooling
Illustrations: The Humidity Chart, Operation of a Water-Cooling Tower
Drying Operations
Illustration: Debugging of a Vinyl Chloride Recovery Unit
Heat Effects in a Catalyst Pellet: The Nonisothermal Effectiveness Factor
Illustration: Design of a Gas Scrubber: The Adiabatic Case
Practice Problems
SELECTED REFERENCES
APPENDICES
The D-Operator Method
Hyperbolic Functions and ODEs
SUBJECT INDEX