INTERACTIONS BETWEEN A BITUMINOUS COAL AND AROMATIC-HYDROCARBONS AT ELEVATED-TEMPERATURES

Proton NMR has been used to investigate interactions between a high-vo latile bituminous coal and a number of aromatic hydrocarbon additives during heating at elevated temperatures. A coal-additive ratio of 4:1 was used. Coal tar pitch and aromatic hydrocarbons such as anthracene were observed to penetrate the coals at temperatures >200 degrees C an d substantially increased the extent to which the coal was mobile at t hese temperatures. If, after the hydrocarbon had penetrated the coal, the mixture was allowed to cool to room temperature and then was rehea ted, the extent to which the mixture was mobile was substantially alte red. The extent to which the reheated mixture was mobile at 100 degree s C decreased with both increasing molecular weight and increasing pol arity of the additive but was not dependent on the melting point of th e additive. Studies using deuterated anthracene showed that the coal i n these reheated mixtures itself started to become significantly mobil e at similar to 150 degrees C, that is, at temperatures at which neith er coal nor anthracene alone was mobile. These results are interpreted in terms of a general interaction between the coal and the hydrocarbo ns that is probably electrodynamic in nature.