Separation of Aromatic Isomers by Supercritical Fluid Phase Adsorption

为阐明超临界相吸附分离机理，以NaY型沸石为吸附剂，研究了2，6-和2，7-二甲基萘(DMN)异构体混合物在超临界二氧化碳中的吸附行为。实验在不同的温度和压力下进行，考察了温度和压力对吸附行为的影响。结果表明，在压力较高或温度较低的两组分体系中，2，6-DMN和2，7-DMN的分离效率较高，吸附量较小，穿透时间较短。此外，在假设线性吸附平衡的前提下，用传质系数模型关联了所有体系的实验穿透曲线。该模型对所有实验穿透曲线均给出了较好的关联结果。

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.