Abstract: To realize the resource utilization of light slurry produced in the C₈ processing industrial chain, the process route of recycling light slurry at the top of the coke drum in the delayed coking unit was selected. The operation results show that processing light slurry by injecting it into the top of the coke drum through the defoamer line has solved the outlet problem of light slurry. A total of 21 793.8 t of light slurry was processed in 2025, increasing economic benefit by 27.93 million yuan, which demonstrates significant industrial application value.After recycling light slurry, high vibration occurred at the outlet pipeline of the light slurry blending pump, which was significantly improved by adjusting and reinforcing pipeline supports and replacing with a larger accumulator. The liquid level in the overhead circulating oil collection tank of the fractionation column fluctuated, and the filter of the overhead circulating oil reflux pump was blocked; the operation of the overhead circulation system was improved through operation adjustment and equipment maintenance.The color of coker gasoline and coker diesel became darker, while their distillation ranges showed no obvious change. The reaction temperature in the coke drum decreased, and the volatile matter of petroleum coke increased significantly, with a maximum rise of 2.0 percentage points.

Key words: delayed coking unit, light slurry, overhead circulation, petroleum coke, fouling, economic benefit