MATHEMATICAL-MODELING OF HEAT AND MASS-TRANSFER IN PACKED-BED ADSORBERS REGENERATORS

Nonisothermal adsorption is studied by incorporating its mathematical description into a model consisting of the full two-dimensional Navier -Stokes equations and energy and species concentration equations to si mulate the processes in fixed-bed industrial adsorbers/regenerators. T he model partial-differential equations are solved numerically by usin g well-established computational fluid dynamics techniques. The equili brium between gas and solid is considered nonlinear, which is describe d by Freundlich-type equations. The transport and adsorption of a comp ound from a solvent to and into an adsorbent are described by a two-st ep process: transport through the ''film'' to the outer surface of the particle and diffusion into the porous particle. The effect of fill r esistance is discussed, as well as a two-equation turbulence model. So lutions obtained for a typical industrial adsorber/regenerator demonst rate the potential of this method. The computed results for various fl ow ratios and parameters in the Freundlich equations are shown to be p hysically plausible.