ELUCIDATION OF COAL-LIQUEFACTION MECHANISMS USING A TRITIUM TRACER METHOD - HYDROGEN-EXCHANGE REACTION OF SOLVENTS WITH TRITIATED MOLECULAR-HYDROGEN IN THE PRESENCE AND ABSENCE OF H2S

To estimate the hydrogen mobility of solvents quantitatively, reaction s of tetralin, decalin and naphthalene with tritiated gaseous hydrogen in the presence and absence of H2S were performed under the condition s generally used for coal liquefaction (400 degrees C, initial hydroge n pressure 60 kg/cm(2)). The conversions of tetralin and decalin to ot her organic structures in the presence and absence of H2S were very cl ose to each other. However, the conversion of naphthalene in the prese nce of H2S was promoted about four times of that in the absence of H2S . In the absence of H2S, the hydrogen exchange ratio (HER: the ratio o f hydrogen exchanged in a solvent to total hydrogen in the solvent) of naphthalene was highest among the solvents. However, in the presence of H2S, the HERs of tetralin and decalin were promoted about 10 times. In the presence of H2S, the HER of tretalin was highest in comparison with those of decalin and naphthalene. It was suggested that H2S prom oted the hydrogen exchange through tetralyl radical. (C) 1998 Elsevier Science Ltd. All lights reserved.