烷烃在分子筛孔中吸附和扩散的分子模拟  

Molecular simulation study of adsorption and diffusion on zeolites for alkanes

作　　者：陈玉平[1] 吕玲红[1] 陆小华[1] 

机构地区：[1]南京工业大学化学化工学院,江苏南京210009

出　　处：《计算机与应用化学》2007年第7期867-871,共5页Computers and Applied Chemistry

基　　金：国家杰出青年科学基金(29925616);海外青年学者合作研究基金(20428606);国家自然科学基金(20236010;20246002;20376032);江苏省自然科学基金(BK2002016);国重点基础研究发展计划(973计划:2003CB615700)资助.

摘　　要：用巨正则系综蒙特卡罗(grand canonical monte carlo,GCMC)和构型偏倚蒙特卡罗(configurational-bias monte carlo,CB- MC)相结合的模拟方法,研究300 K下,烷烃(甲烷、乙烷、丙烷、丁烷)在ISV、MEL型分子筛上的吸附,饱和吸附量的大小顺序为:甲烷>乙烷>丙烷>丁烷。模拟甲烷-乙烷、乙烷-丙烷混合物在分子筛(ISV、MOR、MEL型)中的吸附分离,结果甲烷-丙烷比乙烷-丙烷混合物更易分离。采用分子动力学(molecular dynamics,MD)模拟方法,研究甲烷在MEL、MOR分子筛上的扩散系数,分别为2.76-3.86 m^2·s^(-1)、3.14-13.30 m^2·s^(-1),烷烃在分子筛中的扩散与吸附相关,且扩散系数的大小与分子筛的结构有关。模拟所得的有关吸附扩散性质的数据对于化工生产、研发和设计具有指导意义。We employed Grand Canonical Monte Carlo（GCMC） combined with Configurational-Bias Monte Carlo （CBMC） technique to simulate the adsorption of alkanes in ISV, MEL at 300 K. The order of saturated adsorption quality is methane 〉 ethane 〉 propane 〉 butane. The separation of methane-propane, ethane-propane were studied by simulation. The result shows the separation of methanepropane is easier than ethane-propane in ISV, MOR and MEL zeolites. The diffusion coefficient for methane in MEL and MOR zeolites are 3.86 -2. 76 m^2·s^-1 , 13.30 -3.14 m^2·s^-1 by molecular dynamics （MD） simulation, respectively. It was found that the adsorbed amount of alkanes has a pronounced effect on the diffusion property and the size coefficient of diffusion has related to the structure of zeolites. The data of adsorption and diffusion is useful for production and studies and design.

关 键 词：烷烃 吸附 扩散 分子筛 分子模拟 

分 类 号：TQ424[化学工程]