Transport of penetrants in the macromolecular structure of coals: 4. Models for analysis of dynamic penetrant transport

Abstract

Mathematical models are presented which can be used to describe Fickian (Case-I) diffusion and Case-II transport in thin coal slabs, spheres and cylinders. Useful short-time approximations for each of these models are also presented. From heuristic arguments, based on these short-time solutions, a semi-empirical equation is developed, which is useful in defining anomalous transport behaviour in the macromolecular network structure of coal. The utility of this empirical equation is considered.