Deep Hydrotreatment of Middle Distillates Obtained by Pyrolysis of Oil Shale and Oil Sands Bitumen

Abstract

Middle distillates obtained by pyrolysis of oil shale and oil sands bitumen were denitrogenated by complex formation with CuCl2·2H2O, which reduced the nitrogen contents from 9900 to 2700 wtppm and from 1300 to 700 wtppm, respectively, without any change in the sulfur contents. The original and denitrogenated oils were hydrotreated over a conventional NiMo catalyst in a fixed-bed continuous flow reactor. The pre-removal of nitrogen compounds greatly enhanced hydrodenitrogenation (HDN) and hydrodesulfurization (HDS), and the rate constants were increased by 4.9-27 for HDN and 2.8-5.4 for HDS. As a result, the nitrogen and sulfur contents of the denitrogenated oils were reduced to < 1 and < 10 wtppm, respectively, under the conditions of H2 8 MPa, LHSV 1 h−1 and 350°C.