1. ADVANCED MASS TRANSFER
Amirkabir University of Technology
(Tehran Polytechnic)
ADVANCED MASS TRANSFER
By:
Dr. Frazin Zokaee
Chemical Engineering Department
Winter 2009

2. Course Outline: CHAPTER 1: FLUX DEFINITION
Mass and Molar Transport by Convection
Summary of Mass and Molar Fluxes
Fick’s Law
CHAPTER 2: DIFFERENTIAL EQUATIONS OF MASS TRANSFER
Differential equation for mass transfer
Boundary conditions
CHAPTER 3: MOLECULAR DIFFUSIVITIES
Diffusivities in Gases
Diffusivities in Liquids
By Dr. Zokaee

3. CHAPTER 4: MOLECULAR DIFFUSION
Steady-State Molecular Diffusion
Steady-State Equimolal Counter Diffusion in Gases
Steady-State Unimolal Unidirectional Diffusion in Gases
Molecular Diffusion in Liquids
Diffusion through a Stagnant Gas Film
Diffusion with a Moving Interface
Diffusion through a Nonisothermal Spherical Film
Diffusion with a Heterogeneous Chemical Reaction
Diffusion with a Slow Heterogeneous Reaction
Diffusion with a Homogeneous Chemical Reaction
Unsteady-State Diffusion in a Sphere
Unsteady-State Diffusion in a Slab
Unsteady-State Diffusion in a Cylinder
By Dr. Zokaee

4. CHAPTER 5: MECHANISMS OF MASS TRANSFER
The Two-Film Theory
The Penetration Theory
The Theory of Penetration with Random Surface Renewal
CHAPTER 6: MASS TRANSFER IN LAMINAR FLOW
Mass Transfer in the Laminar Boundary Layer on a Flat Plate (Integral Solution)
Mass Transfer in Laminar Natural Convection on a Vertical Plate
Mass Transfer in a Falling Liquid Film in Laminar Flow
Mass Transfer Between a Gas Phase and a Falling Liquid Film (Gas Absorption)
Mass Transfer Between an Inclined Plate and a Falling Liquid Film(Solid Dissolution)
Gas Absorption with Rapid Reaction
تعداد جلسات بعدا اصلاح شود
By Dr. Zokaee

5. CHAPTER 7: MASS TRANSFER IN TURBULENT FLOW
Mass Transfer in the Turbulent Boundary Layer on a Flat Plate
Mass Transfer in Turbulent Natural Convection on a Vertical Plate
Mass Transfer Between an Inclined Plate and a Falling Liquid Film in Turbulent Flow
Analogies Between Momentum, Heat and Mass Transfer
Reynolds Analogy: Analogy Assuming Only a Turbulent Core
Prandtl Analogy: Analogy Assuming a Laminar Sublayer and a Turbulent Core
Von karman Analogy: Analogy Assuming a Laminar Sublayer, a Buffer Zone and a Turbulent Core
Analogies in terms of j Factors
By Dr. Zokaee

6. Text Book
A. H. P. Skelland, Diffusional Mass Transfer, John Wiley and Sons (1974).
R.B. Bird, W.E. Steward and E.N. Lightfoot, Transport Phenomena, 2nd Ed., John Wiley and Sons (2002).
J. R. Welty, C. E. Wicks, R. E. Wilson and G. Rorrer, Fundamentals of Momentum, Heat, and Mass Transfer, 4th Ed., John Wiley & Sons (2001).
By Dr. Zokaee

7. What is Mass Transfer?
The transport of one component from one place to another is called Mass Transfer.
Motion of molecular or fluid elements caused by some form of potential or driving force is called Mass Transfer.
Diffusional Mass Transfer involves the migration of one substance through another under the influence of a concentration gradient .
Must have a mixture of two or more species for mass transfer to occur.
By Dr. Zokaee

8. Separation processes Gas - Liquid Single phase Gas - Solid
Absorption
Stripping
Distillation
Evaporation
Humidification
Dehumidification
Single phase
Gas - Solid
Adsorption
Desorption
Drying
Sublimation
Direct contact
Liquid - Solid
Adsorption
Desorption
Leaching
Crystallization
Between two phase
Liquid - Liquid
Indirect contact
Membrane separation
Liquid-Liquid
Extraction
By Dr. Zokaee

9. Types of Membrane Porous membrane Dense membrane Solid diffusion
Permeability
By Dr. Zokaee

10. Driving force in Membrane separation
Microfiltration
Pressure gradient (∆P)
Ultrafiltration
Dialysis
Concentration gradient (∆C)
Nanofiltration
Pervaporation
Reverse Osmosis
Electric gradient (∆E)
Gas Permeation
Electro Dialysis (ED)
Liquid Membrane
Temperature gradient (∆T)
Membrane Distillation
By Dr. Zokaee

11. Mechanical Separation
Mechanical work and calculations are according the fluid flow in
porous media and centrifugal force and etc.
Mixing
Size reduction
Sedimentation
Centrifugation
Filtration
By Dr. Zokaee

12. Separation processes Continues Packed towers Spray towers
Bubble column
Wetted wall column
Stage wise
Tray towers
Mixer and Settler
By Dr. Zokaee