Abstract: In order to realize the high value-added utilization of the diesel fraction from residue hydrotreating (RHT) unit and give full play to the role of hydrocracking units in reducing diesel fuel, a commercial test of RHT diesel fraction was carried out in a hydrocracking unit. The load rate of hydrocracking unit was 56%, and after blending 21.4% RHT diesel fraction, most of the RHT diesel fraction could be converted into non diesel components, with an apparent conversion rate of 48.34%. The mass fraction of sulfur and nitrogen in hydrocracking diesel products was 1.3 μg/g and less than 0.3 μg/g, respectively. Compared to that of the diesel hydroupgrading unit, the properties of diesel product were slightly improved, with the cetane number of 62.7, which increased by about 17, and the total output of diesel product decreased by 14.09 t/h. The hydrocracking unit was used to process RHT diesel fraction, the process route was optimized, the component of diesel fuel was effectively reduced, and the quality of diesel fuel was improved. It can provide an industrial case for the high value-added utilization of RHT diesel fraction.

Key words: hydrocracking, residue hydrotreating, diesel, cetane number