正戊烷和正己烷在无黏结剂5A分子筛上的吸附动力学特性  

Adsorption Kinetics of n-Pentane and n-Hexane on Binder-Free 5A Molecular Sieve

作　　者：沈本贤[1] 孙辉[1] 

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237

出　　处：《石油化工》2008年第8期805-809,共5页Petrochemical Technology

基　　金：国家重点基础研究发展规划(973)资助项目(2006CB202501);中国石油化工股份有限公司资助项目(105032)

摘　　要：测定了正戊烷和正己烷在无黏结剂和有黏结剂5A 分子筛上的吸附动力学,采用简化的扩散动力学模型计算了扩散系数,并估算了扩散活化能。实验结果表明,正构烷烃在无黏结剂和有黏结剂5A 分子筛颗粒上的吸附分别受微孔扩散控制和大孔扩散控制。黏结剂的存在降低了正构烷烃的扩散速率。在300～480 K,正戊烷和正己烷在无黏结剂5A 分子筛上的微孔扩散系数分别为(4.71～11.34)×10^(-12),(1.23～5.19)×10^(-12)cm^2/s;在有黏结剂5A 分子筛上的大孔扩散系数分别为(6.68～26.35)×10^(-6),(2.40～11.51)×10^(-6)cm^2/s。正戊烷和正己烷在无黏结剂5A 分子筛上的扩散活化能分别为7.87,10.15 kJ/mol;在有黏结剂分子筛上的扩散活化能分别为9.02,10.92 KJ/mol。Adsorption kinetics of n-pentane and n-hexane on 5A molecular sieve with/without binder were studied. Diffusivities were derived from simplified model and diffusion activation energies were evaluated. Adsorption rate of n-paraffins on 5A molecular sieve pellets without binder is controlled by micropore diffusion while on 5A molecular sieve pellets with binder is controlled by macropore diffusion. In temperatures range of 300 - 480 K, diffusivities of n-pentane and n-hexane on binder-free pellets are （4. 71 - 11. 34） 10^-12 and （ 1. 23 - 5. 19） 10^-12 cm^2/s, respectively. Diffusivities of n-pentane and n-hexane on the pellets with binder are （ 6.68 - 26. 35 ） 10 ^-6 and （2.40 - 11.51 ） 10 ^-6 cm^2/s respectively. The diffusion activation energies of n-pentane and n-hexane are 7. 87 and 10. 15 kJ/mol for binder-free 5A molecular sieve respectively, and 9. 02 and 10.92 kJ/mol for 5A molecular sieve with binder respectively.

关 键 词：正戊烷 正己烷 5A分子筛 吸附动力学 扩散控制机理 

分 类 号：TQ028.15[化学工程]