Abstract: In order to solve the problem of low load of hydrocracking unit and poor quality of secondary diesel, SINOPEC Beijing Yanshan Company adjusted the feedstock compositions of hydrocracking unit by blending a certain proportion of FCC diesel or coker diesel. The two solutions were compared. Blending coker diesel as feed, the outlet temperature of the second bed of refining reactor decreases by about 8.6 ℃, the total temperature drop of refining reactor declines by 19.4 ℃. The total pressure drop of refining and cracking reactors decreases. When the conversion is 68.0%, the hydrogen consumptions of blending FCC diesel and coker diesel are 3.48% and 3.10%, respectively. Aromatics content in aviation fuel is down from 15.7% to 6.1%, the smoke point increases 1.5 mm, the yield of diesel increases 7.26 percent points, the cetane number rises 3 points, and the BMCI value of tail oil reduces by 0.7, the overall energy consumption showed a slight increase of 1.6 MJ/t.

Key words: hydrocracking, FCC diesel, coker diesel, hydrogen consumption, jet fuel