A study on process for slurry-bed hydrotreating of distillate oil:
II Processing conditions and kinetics analysis of FCC diesel oil

Slurry-bed hydrogenation processing conditions of FCC diesel oil were optimized, and hydrodesulfurization(HDS) and hydrodenitrogenation(HDN) kinetics were also studied over slurry-bed hydrogenation catalyst (SP25). The results indicated that the catalyst activity increased with increase of reaction temperature(t), pressure(p), catalyst additional weight(w_catatlyst) and reaction time(t). The optimal process conditions were t=350℃, p=6MPa, w_catatlyst= 6%, t=2h. The results of catalyst recycling performance suggested that catalyst SP25 possessed good activity stability. Kinetic data showed that the FCC diesel oil HDS reaction could take place in two reaction stages. The first stage is HDS of benzothiophenes(BTs), which are easier to be hydrodesulfurized among sulfur-containing compounds in FCC diesel oil. The reaction activation energy is 70.00kJ/mol. The second is HDS of dibenzothiophenes(DBTs), which are more difficult to be hydrodesulfurized. The reaction activation energy is 85.65kJ/mol. The reaction activation energy for diesel HDN reaction is 79.91kJ/mol. Alkyl-DBTs, especially DMDBTs were the the most difficult to be removed heteroatom-containing(S and/or N) hydrocarbon compounds in hydrotreating reaction.