IN-SITU IMPREGNATED IRON-BASED CATALYSTS FOR DIRECT COAL-LIQUEFACTION

Three methods of preparing catalysts for direct coal liquefaction (DCL ) are presented, using ferric sulfide as a precursor. Of these, one in volves the physical mixing of the coal and the supercritically dried c atalyst, and the other two involve impregnation of the catalyst in the coal. In one of the latter two, the catalyst is prepared in situ as w ell. The in situ impregnated sample (IIS) of catalyst plus coal result s in a high level of coal conversion. The nominal loading of the catal yst is 1.67 wt%, but even lower loadings, <0.5 wt%, show significant i mprovements in activity and oil yield relative to uncatalysed DCL. For DCL using the IIS catalyst, a solvent with negligible hydrogen-donati ng and shuttling abilities can be used; a more active solvent, with gr eater ability to donate and shuttle hydrogen from the gas phase to the coal, results in only a slight improvement in activity and oil yield. Hence the IIS approach appears to be an efficient method of catalyst introduction for carrying out catalytic DCL.