Effect of Coal Characteristics and Molybdenum Sulfide Catalyst on Conversions and Yields of Heavy Products from Liquefaction in Phenanthrene

Abstract

Eight coals, ranging in rank from subbituminous B to high-volatile A bituminous, were reacted in microautoclave reactors in a hydrogen atmosphere and with the nondonor solvent phenanthrene. Reactions were conducted at 360 °C for 1 h. Both noncatalytic and catalytic reactions were investigated. The catalytic reactions employed ammonium tetrathiomolybdate as a catalyst precursor. In noncatalytic reactions, conversions ranged from 18 to 47% and showed a dependence on the oxygen contents of the coals. Addition of a catalyst increases conversions to 54−83%. In catalytic reactions there is no apparent dependence of conversion on oxygen content, but rather the hydrogen content, the net hydrogen (the total hydrogen corrected for oxygen, sulfur, and nitrogen), and its distribution in the coal structure are important. Segregation of the coals into groups originally defined by Given shows two different effects of added catalyst: for medium- to low-rank medium-sulfur coals the available hydrogen in the coal and that...