分离石脑油中单甲基异构烷烃吸附剂的制备及吸附性能研究

采用水热合成法制备用于分离石脑油中单甲基异构烷烃的ZSM-5分子筛吸附剂，以2-甲基戊烷/环己烷溶液为吸附体系，考察不同合成条件对分子筛吸附性能的影响。结果表明：在硅铝比为80、25 ℃、陈化时间为36 h、晶化时间为48 h的条件下，以正丁胺为模板剂，合成ZSM-5分子筛吸附剂对2-甲基戊烷吸附量为2.39 g/(100 g)，比参比ZSM-5分子筛对2-甲基戊烷吸附量高约20%；采用合成ZSM-5分子筛对石脑油进行吸附分离，吸附组分中正构烷烃和单甲基异构烷烃质量分数为97.47%；吸余油的芳烃潜含量从23.19%提高到34.21%；通过合成ZSM-5分子筛吸附分离可以将石脑油中质量分数约为30%的正构烷烃和约12%的单甲基异构烷烃分离出来。

SYNTHESIS AND ADSORPTION PROPERTY OF ZSM-5 ABSORBENT FOR SEPARATING MONOMETHYL ISOPARAFFIN FROM NAPHTHA

In order to improving the utilization efficiency of hydrocarbons in naphtha, zeolites ZSM-5 was synthesized by hydrothermal method to separate monomethyl isoparaffins from naphtha. The effects of preparation conditions on the properties of zeolites ZSM-5 were investigated using 2-methylpentane/cyclohexane as separation system. The optimum preparation conditions for zeolites ZSM-5 were using n-butylamine as the template, the SiO2/Al2O3 of 80, the aging time of 36h and the crystallizing time of 48 h. The static saturated adsorption capacity of zeolites ZSM-5 synthesized in this paper was 2.39 g 2-methylpentane/(100 g) zeolite at 25 ℃, which is 20% higher than the contrastive zeolites ZSM-5. The total content of normal paraffins and monomethyl isoparaffinsin naphtha was 97.47% after the adsorption separation by zeolites ZSM-5. The potential aromatic contents of naphtha was increased from 23.19% to 34.21%.The content of 30% of normal paraffins and 12% monomethyl isoparaffins was separated from naphtha with synthesized zeolites ZSM-5.