Structural changes induced by thermal treatment of deashed coals

摘要

The thermal treatments of three coals of different rank and those deashed coals below 473K in a nitrogen atmosphere were carried out, the structural changes in the treated coals were investigated from the yield of pyridine soluble (PS), the volumetric swelling ratios using methanol (MQ), and the contents of oxygen-containing functional groups. During the thermal treatments, the values of H/C, O/C, PS and MQ in the lower rank coals decreased gradually because of the development of cross-linking among the functional groups. For higher rank coal having a small content of oxygen-containing groups, the variations of H/C, O/C and MQ values were negligible.