DETERMINATION OF HYDROGEN DONOR ABILITY OF HEAVY OILS BITUMENS AND ITS EFFECT ON COAL DISSOLUTION

The hydrogen donor abilities of several heavy oils/bitumens used in CANMET coprocessing were determined using chemical methods (1,1'-binaphthyl and sulphur as hydrogen acceptors) and a C-13 n.m.r. technique. The degree of hydrogen donor ability (HDA) of each material was compared with values for model compounds such as tetralin, 9,10-dihydroanthracene and liquefaction solvents such as hydrogenated anthracene oil and raw anthracene oil. Results showed that the coprocessing heavy oil and bitumen solvents have similar hydrogen donor abilities regardless of their origin, as determined by the above methods. In support of these findings, solubilization of Forestburg subbituminous coal in these solvents both in nitrogen and hydrogen atmospheres was similar. Further, the coal conversion to THF solubles was not affected by either the saturate or the asphaltene contents in these oils/bitumens. However, depending on the method used, the measured HDA of heavy oils/bitumens was higher or lower than that of tetralin. Factors such as the physical interaction between solvent and coal are discussed.