催化裂化轻循环油生产高辛烷值汽油或轻质芳烃(LTAG)技术关键及实践

基于对催化裂化轻循环油(LCO)烃类组成分子水平表征、LCO中稠环芳烃加氢反应规律和加氢LCO中四氢萘类单环芳烃的催化裂化与氢转移反应规律的认识,开发了将LCO高效转化为高辛烷值汽油或轻质芳烃的LTAG技术。LTAG技术是LCO加氢与催化裂化的集成技术,其技术关键是将LCO中稠环芳烃通过选择性加氢饱和反应生成四氢萘类单环芳烃,再通过强化加氢LCO中四氢萘类单环芳烃的催化裂化反应和抑制氢转移反应,实现LCO的高值化利用。加氢单元可采用LCO单独加氢或LCO与蜡油或渣油混合加氢模式;催化裂化单元可采用以下两种模式:①加氢LCO单独催化裂化生产高辛烷值汽油馏分或轻质芳烃;②加氢LCO与重油原料分层顺序进料催化裂化生产高辛烷值汽油馏分。LTAG技术对于炼油企业降低柴汽比、调整产品结构和提升产品质量提供了有力的支撑。该技术既解决了劣质LCO的出路问题,又弥补了市场短缺的高辛烷值汽油馏分或轻质芳烃的不足,具有显著的经济效益,在炼油企业得到广泛的应用。

Technical key and practice of producing high octane number gasoline or light aromatics (LTAG) from FCC light cycle oil

Based on the knowledge of hydrocarbon composition molecular level characterization of FCC light cycle oil (LCO), the hydrogenation reaction regularity of polycyclic aromatic hydrocarbons(PAHs) in LCO, and the catalytic cracking and hydrogen transfer reactions characteristics of monocyclic aromatic hydrocarbons(MAHs) like tetralin compounds in hydrotreated LCO, LCO to aromatics or gasoline with high octane number (LTAG) technology was successfully developed. The LTAG technology is the integration technology of LCO selective hydrogenation and fluidized catalytic cracking. The key of LTAG technology is to generate MAHs like tetralin compounds from PAHs in LCO by selective hydrogenation saturated reaction. Then by strengthening hydro-LCO catalytic cracking reaction and inhibiting the hydrogen transfer reaction, hydro-LCO can be converted efficiently to high octane number gasoline or light aromatics. LCO can be hydrogenated individually, or mixed with vacuum gas oil (VGO) or residue oil in hydrogenation unit. Two models could be used in catalytic cracking unit:(1) The high-octane number gasoline fraction or light aromatics is produced by hydro-LCO individual catalytic cracking. (2) The high octane number gasoline fraction can be produced by hydro-LCO and heavy oil feedstock stratified sequential feeding. LTAG technology supports greatly for refineries to reduce the diesel to gasoline ratio, adjust products mix, and enhance products quality. It not only provides a way out for inferior LCO, but also makes up the shortage of high octane number gasoline fraction and light aromatics. Therefore, LTAG has apparent economic benefits and has been widely applied in refineries.