Diffusion in synthetic faujasite powder and pellets

Transient sorption rates of allene and methylacetylene in synthetic faujasite (Linde 13X) powder and self‐bonded pellets are studied in a constant‐volume, constant‐pressure system at three temperatures. The intracrystalline diffusion coefficients are found to be in the order of 10−11 cm2/s and the activation energy for diffusion is 4.0 kcal/g‐mole. A simple bipore distribution model for transient diffusion in macropores and micropores is presented. It agrees well with the experimental data and quantitatively predicts the macropore diffusion coefficients. The flow in the macropores is found to be in the Knudsen flow regime.