Mass Transfer in Gases

Although throughout the text we consider both liquids and gases, in this chapter we consider mass transfer in gases only. We examine the observed deviations from the viscous flow behavior at low pressures (or for very small pore sizes) and consider chemical reactions. The subject of gas diffusion in porous media has been extensively treated by Jackson (1977), Cunningham and Williams (1980), and Wakao and Kaguei (1982). Jackson gives special attention to the multicomponent gas mixtures (more than two components), even though for more than three components and at low gas pressures where the molecular slip occurs, the treatment becomes very difficult because of the interdependence of the individual mass fluxes.