APPLICATION OF PETROLEUM PROCESSING TECHNOLOGY TO THE UPGRADING OF COAL SYNCRUDE

The feasibility of producing distillate fuels (gasoline, diesel and aviation fuels) from coal syncrude was determined. A syncrude from direct liquefaction of subbituminous coal was first deasphalted by ultrasonic disaggregation in n-hexane, to reduce the heteroatom content. The oil was then catalytically hydrogenated in a continuous hydroprocessing unit at 450 degrees C and 10 MPa hydrogen pressure. The hydroprocessed oil was fractionated by vacuum distillation and the cuts obtained were characterized. The high aromaticity of the hydroprocessed oil necessitated a second hydrotreatment under conditions suitable for hydrogenation of aromatic structures. Deasphalting removed 39% of the N, 43% of the S and 47% of the O. The first hydrotreatment removed 99% of the S, 87% of the N and 37% of the O, and increased the H/C ratio. The second hydrotreatment provided an important reduction in aromaticity, necessary to achieve certain fuel quality specifications.