The removal of sulfur from Mequinenza (Spanish) lignite was investigated by hydrodesulfurization reactions in microautoclaves. This lignite is of interest because of its very high sulfur content, 9.94% on a dry basis, of which about 90% is organic sulfur. The reaction variables investigated were temperature, hydrogen pressure, catalyst, and reaction time. The best total sulfur removal was about 77%, achieved at 350°C in 1000 psig H2with an impregnated sulfided molybdenum catalyst. In addition to total sulfur removal, the selectivity to H2S production was also investigated, to evaluate maximizing sulfur removal as H2S rather than as organosulfur compounds in by-product liquids. This work is the first study of sulfur removal using dispersed catalysts in the absence of added liquid vehicle.