Film model approximation for non-linear adsorption and diffusion in spherical particles

✍ Scribed by Giorgio Carta; Alberto Cincotti

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 131 KB
• Volume: 53
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/s0009-2509(98)00156-0

✦ Synopsis

A new approximate rate law for non-linear adsorption and diffusion in a spherical adsorbent particle is developed based on an equivalent film resistance model. The approximation provides a quantitatively correct description of the effect of the adsorption isotherm for parallel pore and solid diffusion as well as of the effect of a variable adsorbed-phase diffusivity. In general, uptake curves calculated with this new approximation compare favorably with the numerical solution of the adsorption-diffusion equation in spherical coordinates producing results of accuracy similar to that obtained when the LDF approximation is used for systems with a constant diffusivity.