催化裂化装置粗汽油作急冷油进提升管回炼改质效果及其影响分析

为降低稳定汽油烯烃含量，中海油惠州石化有限公司4.8 Mt/a催化裂化装置将部分粗汽油走急冷油线进提升管回炼改质。研究了粗汽油回炼对产品分布、产品性质、能耗、油气线路压力分布等的影响。结果表明：粗汽油回炼量达15 t/h时，稳定汽油烯烃体积分数降低了1.3百分点；与粗汽油回炼前相比，粗汽油回炼后转化率由76.07%增加到76.12%，焦炭产率由7.29%增加到7.74%，总液体收率略有下降，硫传递系数由2.89%降至2.28%，汽油产品中苯在芳烃中的占比由4.07%降低至3.93%；轻柴油密度（20℃）由948 kg/m³升至951 kg/m³；粗汽油回炼后，该装置能耗增加90 MJ/t以上，旋流式快分系统（VQS）罩外至气压机入口的压降增加2.5 kPa。粗汽油回炼还能够缓解分馏塔顶部塔盘和塔顶循环系统结盐问题。

EFFECT ANALYSIS OF FCC NAPHTHA USED AS QUENCH OIL IN RISER

In order to reduce the olefin content of stable gasoline,FCC naphtha was used as quench oil in riser in a 4.8 Mt/a FCC unit of CNOOC Huizhou Petrochemical Company.It was found that the recycle of FCC naphtha into riser as quench oil had influence on product property and distribution,pressure distribution of oil and gas pipeline as well as energy consumption.The results showed that the volume fraction of olefins in the stable gasoline decreased by 1.3 percentage points when the quench oil naphtha was 15 t/h.Compared with that before the recycle of FCC naphtha,FCC conversion rate increased from 76.07%to 76.12%,the yield of coke increased from 7.29%to 7.74%,and total liquid recovery decreased slightly;the ratio of benzene to aromatics in gasoline decreased from 4.07%to 3.93%,sulfur transfer coefficient decreased from 2.89%to 2.28%;density of light diesel(20℃)increased from 948 kg/m3 to 951 kg/m3;the energy consumption increased by more than 90 MJ/t;the pressure drop from the outside of VQS to the inlet of air compressor increased by 2.5 kPa.The problem of salt deposition in the top tray and top circulation system of the fractionator was alleviated by the recycle of FCC naphtha.