Objective The effect of catalytic diesel blending ratio on mixed diesel hydrogenation process was investigated.

Methods Aiming at the requirement of material balance in a refinery and the requirement of increasing the blending ratio of catalytic diesel in diesel hydrogenation industrial unit, taking the hydrogenation process of mixed diesel as the research object, the effect of blending ratio of catalytic diesel on hydrogenation process parameters (average reaction temperature), product distribution and product properties were investigated on a hydrogenation pilot plant.The correlation between hydrogenation process parameters and blending ratio of catalytic diesel was established.

Results (1) The material composition tends to be heavier and inferior with the increase of catalytic diesel blending ratio, which leads to a significant increase for hydrogenation difficulty.(2) The established correlation formula between sulfur content in refined diesel, average reaction temperature and catalytic diesel blending ratio could guide the adjustment of process parameters in a certain range.(3) Under the same conditions, with the increase of catalytic diesel blending ratio, the conversion rate of mixed diesel decreased rapidly.Considering the catalyst lifetime, the demands of producing high quality reforming raw material as well as the requirement of producing 3^# jet fuel, it is more suitable to adjust the blending ratio of catalytic diesel to about 30%.The blending ratio could be appropriately increased when the product properties were surplus, and the calibration was completed in industrial plant at the same time.

Conclusions The influence of blending ratio of inferior raw materials on hydrogenation process parameters such as average reaction temperature, products distribution and product properties of hydrocracking were clarified, which can provide reference for similar industrial hydrogenation unit blending inferior raw materials.