Desalination of crude glycerol obtained from biodiesel production by electrodeionization

Abstract

Crude glycerol, which is a by-product from transesterification of vegetable oil in biodiesel production was first filtered through ultrafiltration filters to remove any particles, organic impurities, or matter organic non-glycerol (MONG). Subsequently, the crude glycerol was fed to an electro deionization (EDI) module that used a combination of electricity and ion-exchange resin for desalination in order to prevent reboiler fouling and reduce the energy requirement of glycerol purification by distillation. Furthermore, the effect of water content on inorganic salts removal and power consumption of EDI were studied. The salt removal capability was proportional to the water content, and EDI energy efficiency was significantly increased when the salt concentration decreased. Moreover, the water content also affected the dissolution of organic impurities, which favorably affected the removal of these impurities by the ultrafiltration membrane. All experiments were carried out at room temperature.