Transport of penetrants in the macromolecular structure of coals. V. Anomalous transport in pretreated coal particles

Abstract

Dynamic swelling studies were performed on well-characterized coal particles treated in various ways. Pyridine was the penetrant and all studies were performed at 35°C. The transport behavior was compared for untreated, pyridine-extracted, oxidized and alkylated samples. Data analysis using an exponential equation of the penetrant uptake as a function of time and a relaxation-controlled analysis showed that the pyridine transport mechanism was non-Fickian or Case-II transport, and that it was only slightly affected by the pretreatment of the coal samples.