Mass diffusion in a spherical microporous particle with thermal effect and gas-side mass transfer resistance

An analytical solution for mass diffusion in a spherical microporous particle experienced with a small step change of gaseous phase adsorbate concentration is obtained. The mass diffusion in the solid is assumed to be micropore diffusion controlled. Thermal effect and gas-side mass transfer resistance are considered. The governing equations are solved by using the Laplace transformation method. Three factors, α, β and γ are defined to govern the heat and mass transfer. α and β are relevant to the thermal effect and γ dominates the gas-side mass transfer resistance. The applicable ranges of three simplified models are discussed. A limiting solution with mass diffusivity approaching infinity is obtained.