Abstract: A new processing method for gas oil catalytic cracking unit is proposed. By introducing hydrogenated C₉ as a terminating agent into the riser reactor for recycling, the problem of the utilizing path of hydrogenated C₉ is solved, and the product distribution of the catalytic cracking unit is optimized. The experimental results show that this method significantly increase the yield of light oil by 1.58 percentage points, while ensuring stable operation of the unit, with a 1.38 percentage points increase in stable gasoline yield and a 0.20 percentage point increase in diesel yield. At the same time, it reduces dry gas yield by 0.13 percentage point and coke production by 0.20 percentage point. In addition, this method effectively controls the density and dry point of stable gasoline by adjusting process parameters such as reaction pressure and distillation tower top temperature, providing a new technological solution for integrated refining and chemical enterprises.

Key words: catalytic cracking, hydrogenated c₉, terminating agent, product distribution, light oil yield