Abstract
Intraparticle diffusion parameters 15eK/r2 for adsorption of C2H4 or C2H6 on fixed beds of various porous catalyst particles ranging from 0.008 to 0.1 cm in radius were obtained from the analysis of breakthrough curves. In the case of catalysts having bi-disperse pore size distribution, the parameters are inversely proportional to the square of the particle radius r2 in the region of larger particle sizes, and they approach certain constant values as r2 decreases. These phenomena can be explained as follow : Diffusion of a gas occurs through macro-pores at first, and then the gas penetrates gradually into micro-pores. Thus the effect of pore diffusion on overall adsorption rate depends on the relative importance of macro- and micropore diffusion.
In the case of alumina pellets, which have monodisperse pore size distribution, however, intraparticle diffusion parameters are inversely proportional to r2 throughout the region of particle sizes investigated.
