Abstract
The effects of red-mud and sulfur catalyst on the reaction process of coals treated with hydrogen under high pressure and the chemical structure of the resulting reaction products were dicussed on the basis of the changes in the chemical structure of benzene-solubles using high resolution NMR spectroscopy. These were compared against the results obtained when no catalysts were used.
The effects of red-mud and sulfur catalyst on the conversion were recognized in reaction temperatures (over 350°C in Oyubari coal and over 375°C in Taiheiyo coal) after the onset of the plastic state, namely after the reactants entered the liquid phase.
In the initial reaction course of hydrogen treatment under high pressure up to a conversion of 20 wt. % or thereabouts, it may be said that insofar as this process is concerned, regardless of the presence of red-mud and sulfur catalyst, the results are the same as that when no catalyst was used. Namely, up to a conversion of 20 wt. % or thereabouts the portion of the coal substance in which an uneven distribution of aromatic rings is seen in the structural units, can be dealt with thermal reaction resulting in separation and distillation to benzene-solubles. Red-mud and sulfur catalyst has no catalytic action such as hydrogenation in such a process. On the other hand, in the reaction course after 20 wt. % conversion, it may be said that the reaction of the sample coal proceeds through a plastic state on to a liquid phase, and the chemical structure of coal related to this process is comparatively uniform. In this reaction course the presence of red-mud and sulfur catalyst causes cleavage to occur at the mid Portions of the chains rather than at the bridge structures at the end of the chains.
