Coal Pretreatment for Two-Stage Liquefaction: Final Report: Part 2, Temperature-Staged Coal Liquefaction

摘要

An investigation has been made of the liquefaction of a bituminous and a subbituminous coal under conditions where the reaction is conducted in successive stages of increasing temperature (''temperature staging'') and in the presence of a dispersed sulfided molybdenum catalyst. Experiments were conducted in 30 ml batch tubing bomb reactors and in a more sophisticated 300 ml autoclave reactor system which was operated using a coal injector. Temperature staging has been found to lead to increased coal conversion and improved selectivities of the products to oils at the expense of asphaltenes. These effects were less apparent in the autoclave reactor, where the reaction and product work-up was carried out under different conditions from the tubing bomb experiments. Solvent composition, rank, and the presence of the molybdenum catalyst were found to be significant parameters. Specifically, the effects of temperature staging were more pronounced when low quality solvents were employed. In addition, the lower rank subbituminous coal appeared to be more sensitive to temperature staging than the bituminous coal, and the presence of the molybdenum catalyst produced superior product distributions over noncatalytic runs. An examination of the effects of concentrating huminite at the expense of ash and inertinite by float-sink separation of the subbituminous coal indicated that the deleterious effects of processing had offset any gains made by increasing the concentration of reactive macerals. 80 refs., 34 figs., 23 tabs. (ERA citation 12:049238)