Experimental Dehydration of the Water-Ethanol Mixture by Pervaporation through Membranes Based on Polyvinyl Alcohol: What Conditions for Better Performance?

Abstract

Abstract: The separation processes are of paramount importance in the industrial field. The techniques used to obtain separation membranes depend on the type of membrane and the applications envisaged.
 Aim: The objective of the study is to focus on the master membrane allowing better pervaporation of the water-ethanol mixture by varying various parameters such as the polymer content, the polyacrylic acid (PAA) content and the operating variables such as the drying temperature and the stay in the oven. 
 Materials: We fabricated membranes to separate water-ethanol mixtures by the pervaporation process. First, films based on polyvinyl alcohol and acid polyacrylics were prepared using the appropriate solvent (water) with different PAA contents. We then characterized these films using the technique of infrared spectroscopy and the measurement of swelling of these membranes in water / ethanol mixtures. Pervaporation tests were carried out to measure the selectivity and flow of these films with respect to the mixture.
 Results: All the membranes exhibit a higher permeation flux than that of pure PVA, especially when the PAA content is high. The selectivity to water of these crosslinked membranes, represented by the water content in the permeate is appreciable.
 Conclusion: The addition of PAA to PVA makes possible the improvement of swelling, the flow is improved as well as the water selectivity and the permeability of the membrane which makes the PVA-PAA alloy a simple and effective method to ensure dehydration of the Water-Ethanol mixture.