Microwave-induced spray evaporation process for separation intensification of azeotropic system

Abstract

The microwave-induced film evaporation process has recently been reported as a promising method for separation intensification of polar/nonpolar mixtures. However, the relatively low separation efficiency and evaporation amount caused by massive intermolecular heat transfer with limited evaporation area restrict its industrial application. To this end, an innovative microwave-induced spray evaporator was developed to overcome the current defects. Furthermore, the experiments demonstrated an excellent separation efficiency of alcohol-water azeotropic systems are achieved via microwave-induced spray evaporator (such as the relative volatility of EtOH was more doubled). Moreover, the experiments of several mixtures with different permittivity and dielectric loss were performed to elucidate the mechanism of microwave-induced relative volatility change (MIRVC). The experimental results revealed that the increase of high dielectric loss components in the vapor phase under microwave heating in comparative experiments verifies the inference that dielectric loss determines the direction of MIRVC.