Separation of Aromatic Isomers by Supercritical Fluid Phase Adsorption

以nay型沸石为吸附剂，研究了2,6-和2,7-二甲基萘（DMN）（双组分体系和单组分体系）异构体混合物在超临界二氧化碳中的吸附行为，以阐明超临界相吸附分离机理。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，在双组分体系中，在较高的压力或较低的温度下，2,6- dmn和2,7- dmn的分离效率更高，吸附量更少，突破时间更短。此外，在假设线性吸附平衡的条件下，用传质系数建立了各体系的实验突破曲线的关联模型。该模型对各试验突破曲线均具有较好的相关性。

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.