Promoting coal hydroliquefaction through co-use of water and dispersed molybdenum sulfide catalyst

Work in our laboratory has demonstrated a remarkable synergism between water and a dispersed molybdenum sulfide catalyst for promoting liquefaction of Wyodak subbituminous coal at relatively low temperature (350-375{degrees}C). These results appear to be contrary to conventional wisdom regarding the detrimental effects of water during the catalytic hydroliquefaction of coal. Our findings, to date, indicate that both reaction temperature range and water/coal ratio are key factors in determining the net influence of water upon the catalytic liquefaction of this particular coal. Significantly, we have observed the same promotional trends arising from the co-use of water and dispersed molybdenum sulfide catalyst both in solvent-free experiments, and in liquefaction experiments performed in the presence of either a non-donor (1-methylnaphthalene), or a H-donor (tetralin). In contrast, however, for catalytic runs at higher temperature (400-450{degrees}C), using ATTM without added water always gives the highest conversion, either with or without an organic solvent. These interesting results have demonstrated unequivocally that within a specific temperature window, and in the correct proportion, water can have a dramatic promoting effect on the catalytic liquefaction of Wyodak subbituminous, coal. This paper describes results from the liquefaction of a bituminous coal. Comparisons to the conversion of the subbituminous coal aremore » described.« less