Transport Phenomena II

Code

10678

Academic unit

Faculdade de Ciências e Tecnologia

Department

Departamento de Química

Credits

6.0

Teacher in charge

Isabel Maria Rola Coelhoso

Weekly hours

4

Total hours

70

Teaching language

Português

Objectives

Understanding of mass transfer fundamentals. Mathematical formulation of mass transfer problems for different geometries.Evaluation of diffusion coefficients and mass transfer coefficients. 

Subject matter

1. Fundamentals of mass transfer. Definitions of concentrations, velocity and flux; Fick’s first law. Nernst-Planck equation. Diffusion coefficients; Methods for estimating diffusion coefficients. Diffusion of ionic species. Multicomponent diffusion.
   
2. Differential equations of mass transfer. Boundary conditions. Steady state molecular diffusion; Diffusion through a stagnant film; Equimolal counterdiffusion;
   
3. Diffusion with heterogeneous chemical reaction. Pseudo steady state diffusion.
   
4. Unsteady state molecular diffusion. Stefan-Maxwell equations. Analytical solutions of Fick’s secondlaw.
   
5. Convective mass transfer; Dimensional Analysis; Concentration boundary layer; Models and analogies of Reynolds and Chilton-Colburn; Empirical correlations.
   
6. Interphase mass transfer; Equilibrium gas- liquid and liquid- liquid; Two-resistance theory; Overall and individual mass transfer coefficients.
   
7. Diffusion with homogeneous chemical reaction; Hatta number; First and second order reactions.
   

Bibliography

Cussler, E.L., " Diffusion: mass transfer in fluid systems", 3^rd ed., Cambridge University Press, UK, 2009.

 

Bird, R.B.; Stewart, W.E.; Lightfoot, E. N. Transport Phenomena. 2nd ed. J Wiley & Sons, 2007.

 

Welty, J.R; Wicks, C.E.; Wilson, R.E.; Rorrer G.L. Fundamentals of momentum, heat and mass transfer. 5th ed. John Wiley &Sons, Inc, N.Y., 2010.

 

Courses

• Chemical and Biochemical Engineering