降低催化裂化汽油烯烃技术--FDFCC工艺

根据催化裂化过程中烯烃转化机理，提出了一种并联双提升管催化裂化反应体系——FDFCC工艺，其中一根提升管用于重油裂化，另一根用于汽油改质。工业实施结果表明，该工艺可以显著降低催化裂化汽油的烯烃含量，烯烃体积分数降低20～30个百分点，硫含量下降15％～20％，改质汽油诱导期增加，MON和RON略有增加，芳烃中苯含量基本维持不变，芳烃含量虽有所提高，但远远小于规定指标。与常规FCC工艺相比，FDFCC工艺的汽油产率下降4～5个百分点，液化气和柴油产率均增加2个百分点左右，(焦炭 干气)产率增加小于1个百分点。

TECHNOLOGY FOR REDUCING OLEFIN IN CRACKED NAPHTHA-FDFCC PROCESS

Based on the analysis of olefin conversion mechanism in fluid catalytic cracking, a novel reaction system with side-by-side dual-riser reactor was designed and evolved to FDFCC process. In the reaction system, one riser was for heavy feedstock cracking, and another one was used for cracked naphtha upgrading. The process can obviously decrease the olefin content in cracked naphtha. The results from pilot plant tests and commercial trials in comparison with conventional FCC showed that the olefin content in cracked naphtha dropped by 20-30 percentage points, its sulfur content reduced by 15%-20% with a significant extension of its induction period, and its MON and RON increased slightly while maintaining its benzene content nearly unchanged and its aromatics content far below the specification; the naphtha yield in FDFCC process decreased by 4-5 percentage points; the LPG and LCO yields all increased by around 2 percentage points; and the gas plus coke yield increased less than 1 percentage point.