In order to get information on liquefaction reactivity of coal, effect of pretreatment on transferable hydrogen in coal was studied. The amount of transferable hydrogen in coal was estimated by the method of formation of hydroanthracenes through heattreatment with anthracene. Deashing pretreatment and CO2/H2O treatment increased transferable hydrogen for Taiheiyo and Illinois No.6 coals. From IR measurements the bulk structure of coal was found to be hardly changed by these pretreatments. It can be said that transferable hydrogen is sensitive to the slight change of coal structure. On the other hand, transferable hydrogen was decreased with preheating for Wyoming and Morwell coals. Transferable hydrogen is an evaluating parameter of the pretreatment.
