催化裂化催化剂有机硫氮转化机理量子化学分析  

Quantum Chemical Analysis of Transformation Mechanism of Organic Sulfur and Organic Nitrogen in Catalytic Cracking Catalysts

作　　者：邢梦可 张璇[1] 董智鹤 栾辉 唐智和 王巍树 李巨峰[1] 孟祥海[2] 刘海燕[2] 张睿[2] Xing Mengke;Zhang Xuan;Dong Zhihe;Luan Hui;Tang Zhihe;Wang Weishu;Li Jufeng;Meng Xianghai;Liu Haiyan;Zhang Rui(CNPC Research Institute of Safety&Environment Technology,Beijing,102206;State Key Laboratory of Heavy Oil Processing,China University of Petroleum-Beijing,Bejing,102249)

机构地区：[1]中国石油天然气股份有限公司安全环保技术研究院,北京102206 [2]中国石油大学(北京)重质油国家重点实验室,北京102249

出　　处：《化学通报》2022年第10期1233-1242,共10页Chemistry

基　　金：中国石油直属院所基础科学研究和战略储备技术研究基金项目(2020D-5008)资助。

摘　　要：国家环保法规的日益严格使得对催化裂化(FCC)再生烟气提出了更高的管控要求,再生烟气中污染物组成复杂且转化机制尚不清楚,迫切需要深入理解FCC待生催化剂中污染物的转化机理。对待生催化剂中有机硫和有机氮进行合理简化,选取合适的模型化合物,采用Gassian09软件在B3LYP/def2-TZVP水平下对模型化合物进行几何优化得到最稳定构型,并进行振动分析。利用Multiwfn多功能波函数分析仪对优化后模型化合物进行Laplacian键级(LBO)分析,通过LBO计算结果,得到自由基在再生过程中的详细转化机理。结果表明,含氮化合物中C—N键和含硫化合物中C—S键与C—C键相比均较弱,在催化剂再生过程中会优先发生断裂,生成不同的含氮(NH_(3)、HCN)、含硫(H_(2)S、COS)中间体,随后进一步与氧气反应生成相应的NO_(x)、SO_(x)。Increasingly stringent national environmental protection regulations have put forward higher control requirements for fluid catalytic cracking(FCC) regenerated flue gas. The composition of pollutants in the regenerated flue gas is complicated and the transformation mechanism is unclear. It is urgent to understand the transformation mechanism of pollutants in FCC spent catalysts. The organic sulfur and organic nitrogen in the spent catalysts were reasonably simplified, and the most stable configuration was obtained by selecting the appropriate model compounds and using the Gassian09 software to optimize their geometry at the B3 LYP/def2-TZVP level. The vibration analysis was also carried out. Laplacian bond order analysis(LBO) of the optimized model compounds was performed by the multifunctional wave function analyzer(Multiwfn), and the detailed transformation mechanism of free radicals in the regeneration process was obtained through the calculation of the LBO. The results showed that both the C—N bond in the nitrogen-containing compounds and the C—S bond in the sulfur-containing compounds were weaker than C—C bond, and will preferentially break during the catalyst regeneration process to generate different nitrogen-containing intermediates(NH_(3), HCN) and sulfur-containing intermediates(H_(2)S, COS), which then further reacted with oxygen to generate corresponding NO_(x)and SO_(x).

关 键 词：Laplacian键级分析 待生催化剂 有机硫 有机氮 转化机理 

分 类 号：TE624.9[石油与天然气工程—油气加工工程]