不同条件下重油催化裂化产物的烃组成变化

Hydrocarbon Components of Products from Residue Fluid Catalytic Cracking under Different Reaction Conditions

利用气相色谱和质谱对重油在提升管催化裂化中试装置上反应前后烃组成进行了考察,探讨了在相近转化率时物料反应前后的烃组成变化特点。结果表明,在优化条件下,重油中大分子多环芳烃组分和胶质中的链烷基和环烷基有效裂化生成烯烃和环烷烃,并使双环和三环芳烃分子落入到柴油馏分;烯烃和环烷烃进一步发生芳构化和脱氢反应生成烷基苯。优化条件下热裂化的产物C_1和C_2的产率明显降低,催化反应产物C_3和C_4的产率基本不变;重油馏分中大分子多环芳烃组分和胶质中芳环之间的桥链或环烷基链的断裂导致汽油馏分中C_5～C_7小分子产物明显增加,烯烃的芳构化反应使C_7和C_8短支链的芳烃产率增加;柴油馏分中烷基苯和多环环芳烃增加,而环烷烃和环烷基苯含量减少。

The hydrocarbon components of residue fluid catalytic cracking （RFCC） feedstock and products processed with the technical pilot scale riser FCC apparatus were analyzed by gas chromatography and mass spectrometry, and the characteristics of change for the hydrocarbon components were discussed. In the nearly constant conversion, Alkyl groups and naphthenic groups in polycyclic aromatic hydrocarbons and resin of heavy oil are preferentially converted to olefins, naphthenes and aromatics with two or three rings at the optimal reaction conditions. And then these olefins and naphthenes are opting to be converted to alkylbenzene through aromatization and dehydrogenation. The yield of C1 and Cz as the product of the thermal reaction decreases while that of C3 and C4 as the product of the catalytic cracking remains constant. The content of C5 -C7 of gasoline increases apparently because of the more cracking of alkyl groups and naphthenic groups in polycyclic aromatic hydrocarbons and resin of heavy oil, and the content of C7 and C8 aromatics also increase for the aromatization of olefins. The yields of alkylbenzene and polycyclic aromatic of diesel increase while those of naphthene and naphthenic aromatic decrease.