催化裂化柴油氮化物分布及其加氢反应行为研究

摘要

选择不同来源的催化裂化柴油(LCO),对其全馏分和窄馏分的氮化物进行深入分析,并研究其加氢脱氮(HDN)反应规律,深入探讨LCO中氮化物的分布规律及不同氮化物的加氢反应行为.结果表明:劣质LCO中的氮化物主要以吲哚类氮化物和咔唑类氮化物为主,苯胺类氮化物的含量比较小,且苯胺类氮化物和吲哚类氮化物主要分布在轻馏分段,咔唑类氮化物主要集中在重馏分段;当馏程大于320℃时,LCO中的氮化物含量剧增,且以咔唑类氮化物为主;不同LCO的氮化物分布有较好的一致性.LCO的HDN反应研究表明,咔唑类氮化物的HDN活性明显低于苯胺类氮化物和吲哚类氮化物的HDN活性,且碳数越多越难被脱除;劣质LCO经HDN反应后,产物中出现新的氮化物——苯基吲哚,而随着LCO终馏点的降低,原料中咔唑类氮化物的比例减小,HDN活性增强,产物中没有苯基吲哚生成.%Catalytic cracking diesels(LCOs)from different sources were used to analyze the nitrogen compound distributions in the full fraction and narrow fractions.The hydrodenitrogenation(HDN)reactions of different nitrogen compounds in LCO were investigated.The results showed that indoles and carbazoles are the major components in poor LCO,where anilines account for a small fraction.Additionally,anilines and indoles are mainly in the light fraction,while carbazoles in heavy fractions.The total nitrogen content increases as the boiling point increase,meanwhile a strong increase of carbazoles is observed in over 320 ℃ distillates.The nitrogen distributions of different LCOs have good consistency.The HDN of LCO showed that the reactivity of carbazoles is lower than that of anilines and indoles.The more carbon number in carbazole molecules,the more difficult it is to be removed.In HDN reaction of inferior LCO,a new nitrogen compound,phenylindole,is identified.With the decrease of final boiling point of LCO,the content of carbazoles decreases,HDN activity increases,while no phenylindole is detected.