Progress in Membrane Materials of Pervaporation During Extraction Process of Bio-Ethanol

Distillation is the most common separation operation for miscible liquid mixtures in the chemical industry,including producing bio-ethanol.The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant,particularly for an ethanol concentration of 5%.An alternative membrane process of pervaporation(PV) has been developed in separating ethanol-water mixtures,either alone or in combination with the conventional processes.As a membrane separation technology,pervaporation is especially attractive in the separation of ethanol/water mixtures due to high separation efficiency,low energy consumption and feasible assembly with fermentor.In this paper,membrane separation processes of pervaporation and ethanol extraction technology are reviewed and compared,with an emphasis on the pervaporation membranes as the core of membrane separation processes.Especially the design and advantages of membrane materials reported in the literature are discussed,including hydrophilic and hydrophobic membranes.And further research and development on pervaporation process of bio-ethanol are prospected.