Abstract: Using Daqing coker gas oil as feedstock, a complex denitrogenation agent was developed and the effect of reaction temperature and reaction time on the removal of nitrogen in coker gas oil was investigated to obtain the optimal denitrogenation conditions. Under the optimal conditions of a denitrogenation agent to oil volume ratio of 1:150, a reaction temperature of 80 ℃ and a reaction time of 30 min, compared with feed the treated oil exhibited lower contents of basic nitrogen and aromatic hydrocarbon, cetane number increased by 0.5 units and the treated oil yield was 99.2%. A comparative evaluation was carried out using coker gas oil and treated oil as feedstock respectively, with the same hydrofining catalyst and process conditions: a reaction temperature of 360℃, a reaction pressure of 6.0 MPa, a LHSV of 1.5 h-1 and H2/oil volume ratio of 800. The evaluation results showed that with similar hydrofined oil yields the properties of the hydrofined oil using denitrogenation agent treated oil as feed was better: the contents of nitrogen, sulfur and aromatics was lower 31.5 μg/g, 17.1 μg/g and 6.9%, respectively; cetane number was increased by 7.7 units.

Key words: coker gas oil, complex denitrogenation, hydrofining