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

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. (C) 1997 Elsevier Science Ltd.