Liquefaction of Black Thunder coal. 2. Process severity, gas composition and catalyst selection

Abstract

Autoclave tests confirmed that CO + H 2O was superior to hydrogen for solubilization of Black Thunder subbituminous coal (80–88 wt% coal conversion versus 55 wt% with H 2 at 390°C for 30 min). Syngas could be substituted for pure CO as long as the proportion of other gases did not exceed one third of the total. Potassium carbonate was the preferred water gas shift catalyst from a chemical viewpoint but gave complications in bench-unit operations. This catalyst also gave an improved product composition, i.e. more oils and less asphaltenes/preasphaltenes. Sodium aluminate was the best of the other shift catalysts tested.