Reaction mechanism of coal hydrogenation. 3. Effect of coal type

Seven coals have been hydrogenated in naphthalene and phenanthrene under 10 MPa (initial pressure) of hydrogen with a stabilized niekel catalyst at 400°C for 15 min. Preasphaltene, asphaltene and oil conversions and solvent conversion were measured. The amounts of hydrogen absorbed by coal and by solvent were calculated. Coal conversion and the amount of hydrogen absorbed by coal decreased, while the amount of hydrogen absorbed by solvent increased, with increase in coal rank. The ratio of the amounts of hydrogen absorbed by coal and by solvent showed a good correlation with conversion to benzene- and n-hexanesoluble materials. Naphthalene and phenanthrene gave similar results, suggesting that the coal was hydrogenated directly by gaseous hydrogen.