Enhanced Coal Liquefaction with Ammonia and Amines in Single and Binary Solvent Systems. Seventh Quarterly Report, April 1-June 30, 1985

摘要

To provide a better understanding of the role and fate of primary aliphatic amines as solvent in coal liquefaction, the following potentially important variables were examined: carbon chain length of amine; addition of hydrogen and tetralin to the solvent; and difference among the primary, secondary and tertiary amines. Several major conclusions can be drawn from this study: (1) primary aliphatic amines within a specific range of carbon numbers offer optimal dissolution power, and this range of selection is temperature-dependent. For example, optimum dissolution by amines having four to ten carbons is achieved at 230 exp 0 C; (2) hydrogen enhances the liquefaction rate at 230 exp 0 C. This observation leads to the conclusion that ester cleavage due to nucleophilic attack by amine is not the rate controlling reaction at this temperature although there has been wide speculation concerning this mechanism. Hydrogen is not expected to enhance nucleophilic reactions; (3) tetralin also enhances the rate of conversion, which further suggests that a free radical reaction is involved in the early stage of coal liquefaction; (4) for aliphatic amines with six carbons, primary amine (n-hexylamine) shows a much higher liquefaction efficiency (94%) than dipropylamine (20%) and triethylamine (33%). This could imply that reductive amination of carbonyl in the coal to amine by primary amine could also be an important reaction during liquefaction. 8 refs., 2 figs. (ERA citation 11:010780)