关键词: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">重油催化裂化装置, 低负荷, 油浆回炼, 焦炭, 柴油, 油浆固含量, 烟气粉尘浓度

Abstract: A 2.8 MMTPY heavy oil catalytic cracking unit in a refinery has been undergoing slurry recycling for about six months under low processing capacity. The recycling method involves injecting the recycled slurry into the mixed feed oil at the feed self-protection assembly, and then into the feed oil nozzle. After calibration, the yield of coke increased from 7.86% to 8.41%, accounting for about 20% of the recycled slurry to produce coke. The diesel yield of the unit increased, and about 50% of the recycled slurry was converted into high-value diesel products. The overall conversion rate of the unit decreased due to slurry recycling, with a total reduction of 1.93 percentage points in the yields of dry gas, liquefied petroleum gas, and gasoline. During the slurry recycling process, the feed oil and reaction system were monitored, and no significant impact was found on the reaction system coking, flue gas turbine operation, feed oil pipeline, and nozzle wear. Subsequent defect elimination inspections also found no abnormalities. Overall, the recycling of slurry in the heavy oil catalytic cracking unit can increase the unit's coke yield, ensure steam balance in the entire plant under low processing capacity, and significantly reduce the solid content of slurry, which helps to reduce the unit's slurry yield.

Key words: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">heavy oil catalytic unit, low processing capacity, slurry recycling, coke, diesel, solid content of slurry, concentration of dust in flue gas