LTAG-Ⅱ技术中LCO选择性加氢工艺过程

LCO Selective Hydrogenation Process of the LTAG-Ⅱ Technology

为了降低催化加氢工艺过程氢耗并提高技术经济性,根据催化裂化柴油(LCO)中不同类型芳烃的分布规律特点,在对LCO原料进行轻、重馏分切割分馏基础上,在加氢单元中进行LCO重馏分的选择性定向加氢饱和,然后将LCO轻馏分及LCO加氢重馏分在催化裂化装置进行分区进料,开发了在有效降低氢耗前提下的LCO高效转化为高辛烷值汽油或轻质芳烃的提质增效技术(LTAG-Ⅱ技术)。通过探索不同分馏温度下LCO轻、重馏分的性质特点以及芳烃分布规律,明确苊类、芴类及其衍生物是影响LCO重馏分选择性加氢反应性能的重要因素,确定较适宜的LCO原料分馏温度为240℃;在分馏温度240℃下,相比加氢处理-催化裂化生产高辛烷值汽油组分的单/双向组合技术(LTAG-Ⅰ技术),LTAG-Ⅱ技术在选择性加氢过程中氢耗降低17.7%,LCO原料的归一化转化率可提高4.76百分点,同时汽油收率及选择性均有所提高,具有良好的技术经济性。

To reduce hydrogen consumption in the catalytic hydrogenation process and improve the technical economy,according to the distribution characteristics of aromatics in catalytic cracking diesel oil(Light cycle oil,LCO),LCO feedstocks were fractionated,and then the LCO light fractions and the heavy fractions selectively hydrogenated in the hydrogenation unit were fed into corresponding injection zones of the catalytic cracking unit.The technology for improving quality and efficiency(LTAG-Ⅱtechnology)was developed,which can efficiently convert LCO into high octane gasoline or light aromatic hydrocarbons under the premise of reducing hydrogen consumption.By exploring the aromatics distribution law and reaction characteristics of LCO fractions at different fractionation temperatures,it is made clear that acenaphthene,fluorene and their derivatives are the significant factors affecting the selective hydrogenation reaction performance of heavy LCO fractions.The optimal fractionation temperature is determined to be 240℃.Under this optimal fractionation temperature,compared with the single/bidirectional combination technology of hydroprocessing-catalytic cracking to produce high-octane gasoline components(LTAG-Ⅰtechnology),the hydrogen consumption of LTAG-Ⅱtechnology is reduced by 17.7%,the conversion rate of LCO feedstock is increased by 4.76 percentage point,and the gasoline yield and selectivity are improved,demonstrating its good technical and economic performance.