Dynamic analysis of adsorption on bidisperse porous catalysts

Abstract

Abstract In a variety of catalytic processes dealing with porous catalysts, bidisperse solids arc used. In such systems, it is important to know the adsorption rate together with the diffusion rate in the macro and micropores of the porous solid. In this work, the Dog'u‐Smith (1975) single pellet pulse response method has been used for the simultaneous evaluation of the adsorption and the macro and micropore diffusion parameters in bidisperse porous catalysts. It has been shown that the method succesfully can be applied for fast and accurate evaluation of these parameters. Equations relating the adsorption and diffusion parameters to the measurable properties of the response peak have been derived for a bidisperse pellet. The method experimentally was tested for ethylene adsorption on α‐alumina at 45°C and atmospheric pressure. For a pellet of total porosity 0.73 and macroporosity 0.32, the effective macro and micropore diffusivities and the adsorption equilibrium constant were determined as 0.0334 cm 2 /s, 8.9×10 6 cm 2 /s and 25 cm 3 /g, respectively.