Abstract: According to the requirements of the China VI oil product standard and reducing the diesel/gasoline ratio, PetroChina Karamay Petrochemical Company expanded and upgraded the existing 1.2 Mt/a diesel hydrogenation upgrading unit in May 2018. By a series of means such as adding a new reactor, revamping the fractionation system, adding an absorption stabilization system, and adjusting the catalyst gradation scheme, the processing scale of the unit was expanded from 1.2 Mt/a to 1.5 Mt/a. The full load calibration results showed that the naphtha yield was increased from 14.53% to 32.90%, the diesel yield was reduced from 46.80% to 39.43%, and the diesel/gasoline ratio of the unit was reduced from 3.22 before the modification to 1.20. It is proved that the new catalyst grading system exhibited excellent performance in hydrodesulfurization, denitrogenation, and flexible selectivity, which could meet the needs of oil quality upgrading and lower diesel/gasoline ratio in refineries.

Key words: hydro-upgrading, diesel fuel, diesel/gasoline ratio, China Ⅵ standard diesel