Vapor Phase Separation of Water–Alcohol Mixtures with Industrial Nanofiltration Membrane NaRM

The recovery of lower aliphatic alcohols from dilute aqueous solutions presents a demanding task for solving a number of problems including the generation of energy from renewable raw materials. One of the promising processes for concentrating alcohols is the membrane vapor separation method using water-selective membranes. In this work, the transport and separation characteristics of the industrial nanofiltration membrane NaRM, manufactured by JSC RM Nanotech, in the separation of vapor mixtures of water and aliphatic C₁–C₄ alcohols at a temperature of 60°C have been studied. It has been shown that the transport and separation characteristics of the membrane used in the vapor phase process undergo a significant change, which is associated with the gradual removal of glycerol used as a preserving agent. The obtained stable values demonstrate high water vapor permeability, at the level of commercial pervaporation membranes, and the water/alcohol selectivity in the range of 25–45. The results of the study can help to expand the scope of practical application of the domestic membrane in the processes of recovery of alcohols from dilute aqueous solutions using the membrane vapor separation method.