TON分子筛上丁烷异构体吸附行为的分子模拟

MOLECULAR SIMULATION OF ADSORPTION BEHAVIOR OF BUTANE ISOMERS IN TON ZEOLITE

利用巨正则蒙特卡洛方法,对正丁烷和异丁烷在TON分子筛上的吸附行为进行模拟研究。模拟273,303,373 K下,正丁烷、异丁烷分子在TON分子筛上的单组分吸附等温线,并进行Langmuir,Langmuir-Freundlich,Toth吸附等温线模型拟合,分析其吸附势能、密度分布、吸附热等性质;然后对等物质的量比的正丁烷/异丁烷混合物的吸附进行模拟,考察丁烷异构体的吸附选择性。结果表明:正丁烷、异丁烷在TON分子筛上的吸附更符合Toth吸附模型;与异丁烷相比,正丁烷在TON分子筛上有更高的吸附量;当正丁烷/异丁烷混合组分在TON分子筛上发生竞争吸附时,正丁烷的吸附量远大于异丁烷的吸附量,可判断TON分子筛对正丁烷相比异丁烷有更好的吸附分离效果。

The adsorption behavior of n-butane and isobutane in TON zeolite was simulated by using the Grand Canonical Monte Carlo method.The adsorption isotherms of n-butane and isobutane in the TON zeolite at 273 K,303 K and 373 K were simulated and fitted with the Langmuir,Langmuir-Freundlich and Toth adsorption isotherm models;the adsorption potential,density distribution,adsorption heat were analyzed;the adsorption selectivity of butane isomers was also investigated by simulating the adsorption of n-butane/isobutane mixture with equal mass ratio.The results showed that the adsorption of n-butane and isobutane in TON zeolite was more in accordance with Toth adsorption model,and n-butane had higher adsorption amount in TON zeolite than isobutane.When the mixture of n-butane and isobutane was competitive adsorbed in TON zeolite,the adsorption amount of n-butane was much larger than that of isobutane,it can be concluded that TON zeolite has better adsorption separation effect for n-butane than isobutane.