Pervaporation of aroma compounds: Comparison of membrane performances with vapour-liquid equilibria and engineering aspects of process improvement

The performances of aroma compounds recovery by pervaporation were analysed through an exhaustive review of the literature. Pervaporation is a separation process based on a selective transport through a dense membrane associated with recovery of the permeate from the vapour phase. Thus, the effective selectivity of organophilic membranes was discussed referring to the vapour-liquid equilibria (VLE) of the aroma compounds, which were estimated using thermodynamic data. Firstly, the importance of the nature of the aroma compounds to be extracted in relation with the type of membrane used was emphasized and some chemical groups of molecules were observed to be better separated through the available pervaporation membranes. Secondly, attention was given to the engineering aspects of pervaporation which have to be well-controlled in accordance with industrial aims.