A thermal behavior study of Chinese coals with high hydrogen content

A variety of Chinese coals, rich in barkinite, were studied by thermogravimetric analysis in a nitrogen atmosphere at three heating rates (10, 15 and 25 °C min− 1), as well as fluidity measurement by Gieseler plastometry at a rate of 3 °C min− 1 from 330 °C to 500 °C. Barkinite-rich samples contained higher hydrogen and volatile matter contents and possessed higher H/C atomic ratios than other coals of similar rank. A good correlation between hydrogen and barkinite content was observed. The thermal profiles showed a monotonic weight loss and the reactions were intense. The TGA curves were not greatly affected by the heating rate applied, especially for those coal samples rich in barkinite. In addition, two good linear relationships were found between the H/C atomic ratio and the important parameters derived from DTG curves: total mass loss and the maximum rate of mass loss. The correlations of characteristic parameters derived from thermogravimetric analysis and thermoplastic analysis were also investigated.