Studies related to the structure and reactivity of coals. 15. Conversion characteristics of a suite of Australian coals

Australian coals of varying rank from a well characterized suite and with a wide range of atomic H C ratios have been reacted with hydrogen in tetralin at 405 °C both in the presence and absence of a tin promoter, and with both hydrogen and tin without solvent at 405 °C. The hydogenation activity correlates well with the atomic H C ratio of the coal. The effect of tin promoter is to increase conversion by a similar amount (13 ± 3%) across most of the range of coals, suggesting that similar functional groups are responsible for the reactivity of the macromolecular structure in both high and low rank coals. The coals have also been heated under nitrogen both in the presence and absence of decalin at 320 °C. The guest-host model used previously to successfully explain the reactivity of brown coals may also be applicable to selected higher rank coals. The structurally different semianthracite and algal coals at the two extremes of the H C ratio range (0.51 and 1.65, respectively) show contrasting reactivity patterns to the bulk of the coals studied.