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

Abstract To estimate the hydrogen mobility of solvents quantitatively, reactions of tetralin, decalin and naphthalene with tritiated gaseous hydrogen in the presence and absence of H 2 S were performed under the conditions generally used for coal liquefaction (400°C, initial hydrogen pressure 60 kg/cm 2 ). The conversions of tetralin and decalin to other organic structures in the presence and absence of H 2 S were very close to each other. However, the conversion of naphthalene in the presence of H 2 S was promoted about four times of that in the absence of H 2 S. In the absence of H 2 S, the hydrogen exchange ratio (HER: the ratio of hydrogen exchanged in a solvent to total hydrogen in the solvent) of naphthalene was highest among the solvents. However, in the presence of H 2 S, the HERs of tetralin and decalin were promoted about 10 times. In the presence of H 2 S, the HER of tretalin was highest in comparison with those of decalin and naphthalene. It was suggested that H 2 S promoted the hydrogen exchange through tetralyl radical.