Upgrading of bitumen-derived heavy oils over a commercial HDN catalyst

Abstract

The hydrotreatment of PR Spring bitumen-derived heavy oils was achieved in a fixed-bed reactor over presulfided commercial NiMo/alumina hydrodenitrogenation catalysts. The extents of heteroatom and metal removal and of Conradson carbon residue (CCR) and residuum (> 811 K) conversion were determined as a function of process operating variables: temperature (625–685 K) and liquid hourly space velocity (0.14–0.80 h −1). Pressure and hydrogen/oil ratio were fixed at 13.7 MPa and 890 m 3 m −3 in all experiments. Differences between heteroatom removal and residuum conversion and between CCR conversion and metal removal were investigated and product distributions and yields were studied. The degree of Ni, N and S removal and of CCR and residuum conversion increased significantly as reciprocal LHSV and temperature increased. The residuum fraction (> 811 K) became significantly converted with increasing residence time and the yields of gas oil (617–811 K), distillate (477–617 K), naphtha (i.b.p.-477 K) and C 1-C 4 gases increased continuously. Residuum was significantly converted to volatiles at higher temperatures. The yields of distillate, naphtha and gas increased rapidly at higher temperatures.