Quantitative evaluation of hydrogen transfer related to the appearance of coal plasticity

In order to investigate a relationship between chemical structural changes of coal and their thermoplasticity at the initial stage of coal carbonization process, we conducted the evaluation of donatable hydrogen in coal by the reaction of coal with hydrogen acceptable compounds. We also carried out the measurement of the ¹³C-NMR of coal followed by the estimation of carbon distributions of coal. To obtain more quantitative information, we applied the magic angle spinning method (this is now believed to be the most quantitative) for the measurement. Gieseler fluidity is known to be one of the representative parameters for coking coal. The tendency of the amount of donatable hydrogen of coal vs. coal rank was similar to that of Gieseler maximum fluidity vs. coal rank. In addition to this, it is interested to note that the behaviour of transferable hydrogen estimated based on ¹³C-NMR measurement also showed a close relationship to that of the above parameter These results strongly indicate that the donatable hydrogen seems to be important to the appearance of coal plasticity.