The effect of the concentration dependence of diffusivity on zeolitic sorption curves

✍ Scribed by D.R. Garg; D.M. Ruthven

• Book ID: 103001564
• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 500 KB
• Volume: 27
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(72)85078-4

✦ Synopsis

Solutions of the transient diffusion equation are presented for sorption in a system of spherical particles in which the diffusivity of the sorbate varies with concentration. The functional forms of the concentration dependence of diffusivity considered are commonly observed for the sorption of gases in zeolites. It is shown that, for such systems, a difference between the rates of adsorption and desorption is to be expected. Effective diffusivities are calculated by comparing the theoretical sorption curves for the concentration dependent diffusivity with the standard solution of the diffusion equation for a constant diffusivitv. The validity of the analysis is confirmed by comparison with experimental data.