Polymeric Membranes for Vapor-Phase Concentrating Volatile Organic Products from Biomass Processing

One of the promising technologies in demand is biomass processing to obtain various organic substances including energy carriers and valuable chemicals. Developing processes for the bioprocessing of lignin suggest the use of a synthetic biological system that allows the production of lower aliphatic alcohols through the stage of formation of carboxylic acids. Due to the production of alcohols in the form of dilute aqueous solutions, their recovery and concentration are extremely energy-consuming steps. In this paper, we consider the membrane vapor separation method as applied to aqueous solutions containing alcohols and organic acids. The transfer of vapors of water and С₁–С₄ alcohols through commercial pervaporation and gas separation membranes that have not been studied for this purpose, as well as through a laboratory membrane, has been studied. The highest separation performance of water–alcohol mixtures was demonstrated by the Romakon^TM-PM 102 membrane, which was also investigated in the separation of mixtures with acetic acid. On the basis of the experimental data obtained, mathematical modeling of the process of ethanol recovery from the water/ethanol/acetic acid ternary mixture by the membrane vapor separation method was carried out.