Study on single-stage hydrocracking of vacuum residue in the suspension of Ni–Mo catalyst Original Research Article

Activity of the Ni–Mo/Al2O3 catalyst was studied in a single-stage hydrocracking process of vacuum residue (VR) of Ural crude. The process was carried out in a continuous flow reactor, at the temperature of 410–450 °C, at the pressure of 12–20 MPa, at the liquid space velocity of 0.25–0.75 h−1 and at the gas space velocity of 2500 h−1, and a suspension of the catalyst tested was used. The catalyst was found efficient for the hydrogenation processes, inclusive of hydrodesulphurisation processes, but its cracking activity was moderate. The catalyst concentration and hydrogen pressure did not affect significantly the VR hydrocracking process over the studied scope of parameters, and only some small effect was noticed on hydrodesulphurisation of the cracking products. On the other hand, the reaction temperature and LHSV were found to strongly affect the VR hydrocracking process and to reduce the contents of asphaltenes and CCR, while the impact on hydrodesulphurisation was lower. The reaction rates and activation energy values were determined for those reactions. The conversion figure for VR to distillates (bp < 538 °C) reached 61.6–88.7 wt.% at 430 °C, and sulphur was converted at 70–85 wt.%.