外甩油浆对渣油催化裂化性能影响的研究(下)

STUDIES OF SLURRY DISCHARGE EFFECTS ON RESIDUE CATALYTIC CRACKING PERFORMANCE(Ⅱ)

本文描述了石家庄炼油厂渣油催化裂化装置外甩油浆的实验室研究。通过对油浆物理性质的分析和裂化性能的研究,并在固定流化床装置上模拟了部分回炼的试验,表明油浆的可裂化性明显低于新鲜原料,而生焦量比新鲜原料高得多。在相同转化率下,油浆的生焦量是新鲜原料的3～5倍,而且油浆外甩量越小,其裂化性能越差。对于二连渣油,其适宜的油浆外甩量为5～7w％,这和工业试验的结果是一致的,而最佳油浆外甩量为6.0w％左右。当油浆外甩量由4.56w％加大至6.0w％时,装置的生焦量可降低1个百分点,而新鲜原料处理量可以提高6w％。

This paper presents the studies on the slurries discharged from the FCC unit in Shiji- azhuang Refinery. The compositions of the slurries were analyzed and the catalytic cracking performances of the slurries were investigated in a fixed--fluidized bed reactor. The crackabil- ities of slurries are significantly lower than the fresh feed and its coke formation are much higher. At constant conversion,the coke yields of the slurries are 2～4 times higher than the fresh feed. The cracking performance is even worse when less slurry is descharged. The pi- lot plant result shows that the proper slurry discharge is 5～7 w%, which is in consistent with the commercial operation, and the optimal slurry discharge is about 6.0 w%. When the slurry discharge increases from 4.56 to 6.0w%, the coke yield drops by 1 w% whereas the fresh feed throughput can be increased by 6w%.