In order to clarify swelling effect on liquefaction of coals, swelling ratios, liquefaction yield, heats of wetting, and water contents of coals with various carbon contents have been studied in methanol, tetralin, and mixtures of them.
The swelling ratios of Yallourn coal in all solvents we used were increased up to 60 minutes, and then became a consatant. The more coal swelled in the same solvent, the higher conversion of liquefaction became. The conversions of liquefaction of all dry coals were larger in mixtures of methanol and tetralin (1: 1 by weight) than in tetralin alone. Moreover, the conversion of liquefaction of wet Yallourn coal was also larger in the mixtures of methanol and tetralin than in tetralin alone. This may be contributed that, water molecules which exist in pore parts of Yallourn coal are replaced with methanol molecules; these methanol molecules increase penetration of tetralin into pore parts of it; as a result, the swelling ratio of Yallourn coal is considerably increased.
