FCC油浆精制前后焦化蜡油产物的组成和结构分析

运用GC-FID/MS和NMR从分子水平表征FCC油浆加氢精制前后焦化蜡油产物的详细组成和结构。对其中121种芳烃单体化合物进行分子识别，基本实现该焦化蜡油中多环芳烃、氢化多环芳烃、噻吩和咔唑以及这些化合物的烷基取代物的定量，并考察了油浆精制前后焦化蜡油的结构及其变化。结果表明，尽管FCC油浆加氢精制前后焦化蜡油产物的烃族组成相近，但化合物组成和结构有较大变化。FCC油浆精制后再焦化，蜡油产物中无取代母核多环芳烃加氢转化及缩合减少，烷基桥链的多芳核结构裂化减少，硫、氮杂原子芳香化合物被较多地脱除，C₁和C₂取代芳烃、单环芳烃以及环烷芳烃含量增加，说明加氢精制对FCC油浆延迟焦化过程有利，其焦化蜡油产物的组成和结构得到改善。

Composition and Structure Characterization of Coker Gas Oils Derived From FCC Decant Oil Before and After Hydrotreating

Coker gas oils derived from FCC decant oil before and after hydrotreating were characterized by  GC-FID/MS and NMR. A total of 121 aromatic compounds in the coke gas oils were identified and quantitated, including polycyclic aromatic hydrocarbons (PAHs), hydrogenated PAHs, C₀-C₂ substituted PAHs, thiophenic compounds and carbazoles. The compositional and structural changes in process of hydrotreating-delayed coking of FCC decant oil were also investigated. Coker gas oils derived from FCC decant oils with and without hydrotreating had different compound compositions, though their hydrocarbon group composition were quite similar. The gas oil from hydrotreated FCC decant oil had less unsubstituted polycyclic aromatic and hetero-aromatic hydrocarbons, while more alkyl substituted aromatics and naphthenic aromatics than that from the unhydrotreated one, implying that hydrotreating is beneficial for enhancing cracking and condensation reactions and improving liquid products in delayed coking of FCC decant oil.