REACTION OF METHANE WITH COAL

The reactivities of Australian coals and one American coal with methan e or methane-hydrogen mixtures, in the range 350-400 degrees C and a r ange of pressures (6.0-8.3 MPa, cold) have been examined. The effects of aluminophosphates (AIPO) or zeolite catalysts, with and without exc hanged metals, on reactivity have also been examined. Yields of dichlo romethane extractable material are increased by using a methane rather than a nitrogen atmosphere and different catalysts assist dissolution to various extents. It appears that surface exchanged catalysts are e ffective, but incorporating metals during AIPO lattice formation is de trimental. Aluminium phosphate catalysts are unstable to water produce d during coal conversion, but are still able to increase extraction yi elds. For the American coal, under methane-hydrogen and a copper excha nged zeolite, 51.5% conversion was obtained, with a product selectivit y close to that obtained under hydrogen alone, and with only 2% hydrog en consumption. The conversion under methane-hydrogen was close to tha t obtained under hydrogen alone, while a linear dependence of conversi on on proportion of methane would predict a 43% conversion under metha ne-hydrogen. This illustrates a synergistic effect of the methane-hydr ogen atmosphere for coal liquefaction using this catalyst system. (C) 1997 Elsevier Science Ltd.