COKING AND CRACKING BEHAVIOR OF HEAVY OIL DERIVED FROM THE STUART DEPOSIT

The coking and cracking behaviour of a heavy oil fraction derived from Stuart shale oil was investigated in a moving packed-bed reactor. Exp eriments were performed to evaluate the conversion of heavy oil into l ower-boiling products, coke and gases when contacted with fully burnt shale ash and sand. The oil products were characterized by elemental c omposition, boiling point distribution and n.m.r. spectrometry. The ex perimental data show wide variations in the stoichiometry, depending o n the relative contributions of thermal cracking and coking/catalytic cracking reactions. N.m.r. analyses of the oil products provide insigh t into the mechanisms of heavy oil coking and cracking. The 1-ene:inte rnal-ene ratio of the product oil provides a reliable indicator of the relative importance of these two reactions.