Mathematical analysis is presented for mass transfer in liquid chromatographic columns packed with microporous and macroporous adsorbents using a pore diffusion model and a pore diffusion and adsorption model. The numerical solutions and moment equations show that the two models are mathematically identical, but with different values for the adsorption equilibrium constant, Ke, and the effective intraparticle diffusivity, De. The experimental results on De for liquids in silicalite crystals (micropores) and an activated alumina (macropores), however, suggest that the pore diffusion model is appropriate for microporous adsorbents, and the pore diffusion and adsorption model is suited for macroporous adsorbents. Experimental results also show that values of De for liquids are of a similar order as those for gases in silicalite and are about 3 orders of magnitude smaller than those for gases in the alumina.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering