Separation of Aromatic Isomers by Supercritical Fluid Phase Adsorption

为阐明超临界吸附分离2，6-二甲基萘（DMN）和2，7-二甲基萘（DMN）的机理，研究了NaY型分子筛对溶解于超临界CO2中的DMN异构体混合物（双组分体系和单组分体系）的吸附行为。在不同的温度和压力下进行了实验，考察了温度和压力对吸附行为的影响。结果表明，在较高的压力和较低的温度下，2，6-DMN和2，7-DMN的分离效率较高，吸附量较低，穿透时间较短。此外，所有系统获得的实验穿透曲线相关的模型，使用传质系数，假设线性吸附平衡。该模型对所有的实验穿透曲线都给出了良好的关联结果。

Adsorption behaviors of the isomeric mixture of 2,6- and 2,7-dimethylnaphthalene (DMN) (two-component systems and single-component systems) dissolved in supercritical carbon dioxide using NaY-type zeolite as the adsorbent were studied in order to clarify the mechanism of separation by supercritical phase adsorption. The experiments were performed at the several temperatures and pressures and the effects of temperature and pressure on the adsorption behaviors were examined. It was shown that the higher separation efficiency, the lower adsorption amounts, and the shorter breakthrough times for both 2,6-and 2,7-DMN were obtained at higher pressure or lower temperature in two-component systems. Moreover, the experimental breakthrough curves obtained for all systems were correlated by a model using mass-transfer coefficient by assuming a linear adsorption equilibrium. The model gave good correlation results for the all experimental breakthrough curves.