LAUSR

Abstract Glycerol, as a by-product of biodiesel industries, can be converted into a broad range of high value-added products chemically in the presence of hetero/homogeneous catalysts and also electrochemically in electrolyzers. Using an alkaline medium for glycerol conversion increases the yield of the electrochemical reaction. In several glycerol valorization reactions, water is used as a solvent or is produced as a by-product. Excess water reduces the reaction conversion and hinders the efficiency in alkaline solutions, and hence must be maintained at a low concentration. The removal of water from aqueous salt solutions containing soluble organic species is a very challenging extraction due to the low activity of water. This research seeks to separate excess water from the highly alkaline ternary mixture composed of glycerol, water, and potassium carbonate (K2CO3) by pervaporation. The performance of three commercial hydrophilic PVA-based membranes namely PERVAP™ 4100, PERVAP™ 4101, and PERVAP™ 4155 from DeltaMem AG, Switzerland, was studied in terms of stability, permeability, selectivity, and also lifetime by considering the effect of temperature (25 °C, 45 °C, 55 °C, and 70 °C), water content, and K2CO3 content. Results show that the membranes rejected glycerol and K2CO3 completely. The presence of the K2CO3 in the solution decreased water flux, in part due to reducing water activity.