基于ESI FT-ICR MS对焦化蜡油窄馏分及其催化裂化液体产物中碱性含氮化合物的表征

摘要

利用实沸点蒸馏装置对辽河焦化蜡油进行窄馏分切割,并利用电喷雾傅里叶变换离子回旋共振质谱对窄馏分及其催化裂化液体产物中的碱性含氮化合物进行表征,分别获得随馏分沸点的升高碱性含氮化合物的分布规律和在反应过程中的迁移规律.结果表明,不同窄馏分中都以N1类碱性含氮化合物为主,N1O1类次之,其它类型的相对丰度均较低;随馏分沸点的升高,DBE＞ 10的N1类碱性含氮化合物的总相对丰度明显增加,但其侧链所含碳原子数逐渐减小;DBE＜ 10的N1类碱性含氮化合物的总相对丰度变化不大,但其侧链所含碳原子数显著增加;经过催化裂化反应,不同窄馏分所得液体产物中N1类碱性含氮化合物的结构分布差异显著变小,DBE＜ 10的N1类碱性含氮化合物对催化剂活性位的毒害作用最大.%Liaohe coker gas oil (CGO)was cutted by true boiling point distillation.In order to get the changing rule following with the rising boiling point and transformation in the reaction process,the basic nitrogen compounds in narrow fractions and catalytic cracking products were characterized by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI FT-ICR MS).The results show that the N1 class basic nitrogen compounds are dominant in all the fractions,the relative abundances of other basic nitrogen compounds are so small except the N1O1 class.The relative abundances of N1 class basic nitrogen compounds with DBE ＞ 10 increase significantly with the rising boiling point,but the carbon number of side chains decreases slightly.The relative abundances of N1 class basic nitrogen compounds with DBE ＜ 10 change little,but the carbon number of side chains increases significantly.The distribution of N1 class basic nitrogen compounds in liquid catalytic cracking products derived from different fractions becomes similar.The basic nitrogen compounds with DBE ＜ 10 play a key role in the deactivation of catalytic cracking catalyst.