Effect of Magnetic Field on Rotating Packed Bed Distillation

Abstract

Distillation may be enhanced by an external magnetic field. A liquid mixture of ethanol in water was completely magnetized by permanent magnets with an induction intensity of 0.8 T, and both magnetized and nonmagnetized ethanol–water was used for total reflux distillation in a concentric ring rotating bed (CRRB) that served as a rotating packed bed (RPB). Results showed that the magnetized ethanol–water could significantly and hardly raise the separation efficiencies of the CRRB rotor with malposition and contraposition of holes on adjacent rings, respectively, compared to the nonmagnetized ethanol–water. This demonstrated that the structure of the rotor had a key influence on an increase in distillation separation efficiencies if a magnetized liquid mixture was used. And the gas pressure drop across the CRRB in the distillation also changed with the magnetized ethanol–water, compared to that with the nonmagnetized ethanol–water. In addition, after magnetization, the distillation separation efficiency of the CRRB increased significantly higher than that of the conventional packed column, which meant the high gravity in the CRRB augmented the intensified effect of magnetic field on distillation. Applying a magnetic field for RPB distillation is a novel method of distillation intensification, displaying good application prospects.