HYDROCRACKING OF PETROLEUM AND COAL OILS

Petroleum oils can be hydrocracked at lower hydrogen pressures than coalbased oils and both types of oils have almost similar naphtha yields of 77 to 80% at a pressure of 2000 p.s.i. and 500° C. Coal-based oils produce naphtha of superior quality but with higher hydrogen consumption. At about 80% yield, naphtha from coal oil had a clear research octane number of about 90 with a hydrogen consumption of about 1550 cu. feet per barrel of feed, whereas the product from gas oil had an octane rating of 78 with a hydrogen consumption of only about 1125 cu. feet per barrel. Both types of oils exhibited similar kinetic behavior, with activation energies ranging from about 14,000 to 16,000 cal. per mole. The hydrocracking of these feed stocks must be preceded by hydrorefining to ensure low coke deposition and longer catalyst life. Though the hydrocracking of petroleum oils has certain advantages, the disadvantages associated with coal-based oils could be offset by the superior quality of their products. © 1969, American Chemical Society. All rights reserved.