COAL HYDROLIQUEFACTION USING HIGHLY DISPERSED CATALYST PRECURSORS

In order to discuss the hydrogen transfer process in coal liquefaction with a catalyst in the presence of a donor solvent, hydroliquefaction of Yallourn, Wyoming, Illinois No. 6, and Mi-ike coals and cracking o f benzyl phenyl ether (BPE) were carried out in tetralin or tetralin/n aphthalene mixed solvent under a hydrogen atmosphere with highly dispe rsed catalyst precursors such as Fe(CO)(5)-S, Mo(CO)(6)-S, and Ru-3(CO )(12). In the absence of the catalyst, more than 70% of hydro cn was t ransferred from tetralin, as determined by the formation of naphthalen e. In the presence of Mo(CO)(6)-S and Ru-3(CO)(12), however, the amoun t of hydrogen transferred from tetralin decreased to 15-40% of the tot al hydrogen and that from gas phase increased to 60-85% of the hydroge n required to stabilize coal fragment radicals even with an excess amo unt of tetralin. When the reaction was carried out in the tetralin/nap hthalene mixed solvent, little hydrogenation of naphthalene occurred e ven with the active catalyst. This strongly supports the assertion tha t a decrease in the amount of naphthalene in the catalyzed liquefactio n of coal in tetralin with a catalyst can be ascribed to the direct hy drogen transfer from molecular hydrogen to coal fragment radicals. In the presence of coal or benzyl phenyl ether, little or no hydrogenatio n of naphthalene occurred. (C) 1997 Elsevier Science B.V.