EFFECT OF INTRAPARTICLE FORCED-CONVECTION ON GAS DESORPTION FROM FIXED-BEDS CONTAINING LARGE-PORE ADSORBENTS

The importance of intraparticle convection on the desorption of gases from fixed beds with "large-pore" adsorbents is assessed on the basis of modeling studies. A complete model for isothermal fixed-bed desorption of linear and nonlinear absorbed species includes axial dispersion, intraparticle diffusion, and intraparticle forced convection. Velocity and total pressure changes in the bulk fluid phase as well as in the intraparticle fluid are considered. Several limiting cases are shown as simplifications of the complete model. In a certain range of the number of intraparticle diffusion units, intraparticle forced convection leads to a better efficiency of the desorption process. This is a consequence of the "augmented' effective diffusivity by convection inside the adsorbent particle.