ESTIMATION OF HYDROGEN MOBILITY OF COAL WITH TRITIATED WATER AND GASEOUS HYDROGEN

摘要

To obtain useful fuels and chemicals from coal by liquefaction and pyrolysis, it is important to know the coal structure. Especially, the heteroatom functionalities in coal such as hydroxyl group, thiol, and amino group, etc. play a critical role in the processing of coal because they constitute the more polar fraction of the coal and stabilize free radicals. Recently, we have reported that the tritium tracer methods are effective to determine the amount of hydrogen in the functional group of coal through the reaction of coal with tritiated water and tritiated gaseous hydrogen in a pulse flow reactor as well as a batch reactor. In the pressurized system with tritiated water using the batch reactor, it was assumed that aromatic hydrogen in coal could be exchanged with hydrogen in water. Further, in the reaction of naphthol with deuterium oxide, it was confirmed that aromatic hydrogens at ortho- and para-positions of the hydroxyl group were exchangeable and that no hydrogen in an aromatic ring without the hydroxyl group was exchangeable. According to these findings, in this study, aromatic hydrogens at ortho- and para-positions of functional groups in several Argonne Premium Coal Samples were determined in the reaction with tritiated water using the batch reactor. The results were compared with those from the reaction of coals with tritiated gaseous hydrogen in the presence of a Pt/Al_2O_3 catalyst.