10 Fractionation of Brown Coal by Sequential Thermal Extraction and Subsequent Sequential Solvent Extraction

Abstract

We have previously proposed a coal fractionation which utilizes sequential thermal extraction below at 350℃. In this study we applied the fractionation method to an Australian brown coal, Loy Yang (LY), to examine the validity of the method for fractionating brown coal. By the fractionation method using 1-MN, tetralin, and water as the extraction solvent, LY coal was fractionated into 5 fractions: one solvent soluble fraction at room temperature, 3 extract fractions recovered as solids, and the residue. The total extraction yields using 1-MN, tetralin, and water were 47, 57, and 56%, respectively. All the solid extracts recovered, interestingly, softened and melted below 230℃. The solid extracts obtained using tetralin and water were further separated into 4 constituents, through a sequential solvent extraction, which have different softening and melting behaviours.