ELUCIDATION OF HYDROGEN MOBILITY IN COAL USING A TRITIUM TRACER METHOD .1. HYDROGEN-EXCHANGE REACTION OF COAL WITH TRITIATED-WATER

The hydrogen exchange of coals with water was investigated using a tri tium tracer method to estimate the mobility of hydrogen in coals. The reactions at several temperatures between 50 and 300 degrees C were ca rried out using a glass batch reactor and a pulse flow reactor, respec tively. At lower temperatures, the ratio of hydrogen exchange of coal with water increased with a decrease in rank of coals and tended to ch ange with respect to the content of functional groups such as hydroxyl group, thiol, amino group, and carboxylic acid in coal. From the resu lts obtained from the hydrogen exchange of model compounds of the func tional groups present in coal, it is proposed that the hydrogen only i n the functional group was exchangeable at lower temperature while the hydrogen in aromatic ring substituted by functional groups also becam e exchangeable at 300 degrees C. It was found that the use of the puls e flow reactor as well as the glass batch reactor was very useful faci le and convenient methods to trace the hydrogen exchange between coal and water.