TRITIUM AS A TRACER IN COAL-LIQUEFACTION .3. REACTIONS OF MORWELL BROWN COAL WITH TRITIATED HYDROGEN MOLECULES

The liquefaction of Morwell brown coal was carried out with tritium-labeled gaseous hydrogen. The effects of Ni-Mo-Al2O3 catalyst, reaction time, and temperature on the hydrogen transfer were studied. The relationships between liquefaction conversions and hydrogen-tritium transfers were investigated. Morwell brown coal was easily liquefied at 350 °C, and the conversion reached ca. 100% at 400 °C even without catalyst. The liquefaction proceeded by the hydrogen donation from solvent to coal. Ni-Mo-Al2O3 was not so useful for the coal conversion but was effective for the cracking of the coal liquids. Furthermore, the catalyst promoted hydrogen exchange between the gas phase and the coal. At the initial stage of the reaction, tritium concentrations in heavy components were higher than those in light components, in both the presence and absence of the catalyst, which was reversed at the final stage. © 1990, American Chemical Society. All rights reserved.