KINETICS OF HIGH-CONVERSION HYDROCRACKING OF BITUMEN

To determine the kinetics of residue conversion and yields of distilla tes at very high conversions, bitumen and bitumen fractions were react ed in a 1-L CSTR in a multipass operation. Product from the first pass was collected, then run through the reactor again, and so on. Experim ents were conducted both with Ni/Mo on gamma-alumina hydrocracking cat alyst and without added catalyst, Products were analyzed by distillati on, elemental analysis, microcarbon residue content, and C-13 NMR, The apparent first-order rate constants for residue conversion decreased with increasing level of conversion, once the liquid phase residence t ime had been corrected for flashing of Liquid product at reactor tempe ratures. These decreasing rate constants correlated with the fraction of aromatic carbon in the residue fraction, both with and without adde d catalyst. Sulfur conversion kinetics in the presence of a catalyst w ere consistent with a simple model for conversion of thiophenic specie s into sulfides.