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碱性氮化物(如吡啶、喹啉等)在沸石分子筛上的吸附作用是催化裂化催化剂中毒的重要原因,吸附过程复杂,研究费时且费用高。本文采用巨正则蒙特卡罗方法(GCMC)研究了373 K,473 K和573 K时吡啶、2,6-二甲基吡啶、2,4,6.三甲基吡啶在八面沸石分子筛中的吸附性能,得到了有关吸附平衡常数、吸附热、吸附等温线等信息。计算得到的吸附热顺序为:2,4,6-三甲基吡啶(64.2 kJ/mol)>2,6-二甲基吡啶(59.6 kJ/mol)>吡啶(49.3 kJ/mol),吸附热数值处于文献报道的范围内;在373 K、473 K时,吡啶的饱和吸附量高于其他两种衍生物,吸附等温线能够较好地用Langumir模型拟合;573 K时,2,6-二甲基吡啶的吸附量最高,吡啶的吸附量最低,吸附等温线能够很好地用Freundlich模型拟合。吡啶衍生物在八面沸石分子筛上的吸附热和吸附量不同是由于它们的碱性和分子结构不同造成的。模拟所得吸附数据对于生产、研发、设计具有指导意义。
The adsorption of basic nitrides (such as pyridine, quinoline, etc.) on the zeolite molecular sieve is an important reason for the poisoning of the catalytic cracking catalyst. The adsorption process is complex, time consuming and costly. In this paper, GCM was used to study the adsorption of pyridine, 2,6-lutidine, 2,4,6-trimethylpyridine in faujasite zeolites at 373 K, 473 K and 573 K. Adsorption properties, get the adsorption equilibrium constant, adsorption heat, adsorption isotherms and other information. The calculated order of adsorption heat was: 2,4,6-trimethylpyridine (64.2 kJ / mol)> 2,6-lutidine (59.6 kJ / mol)> pyridine (49.3 kJ / mol) The adsorption values of pyridine were higher than that of the other two derivatives at 373 K and 473 K, and the adsorption isotherms were better fitted by the Langumir model. At 573 K, 2,6- The adsorption amount of lutidine is the highest, the adsorption amount of pyridine is the lowest, and the adsorption isotherm can be fitted well by Freundlich model. The difference of adsorption heat and adsorption amount of pyridine derivatives on faujasite zeolite is due to their different basicity and molecular structure. The simulated adsorption data is of guiding significance for production, R & D and design.