Pervaporative separation of ethanol from an alcohol—ester quaternary mixture

As part of a research project focusing on the development of a sustainable biocatalytic process for production of chiral secondary alcohols, the pervaporative separation of ethanol from ethanol/ethyl acetate/1-methoxy-2-propanol/1-methoxy-2-propyl acetate-mixtures through a commercial PVA-based membrane was investigated. Separation behavior of this mixture was studied in a range of mol fractions (10–70%), temperatures relevant for biocatalytic conversions (35–55 °C) and downstream pressures (35–200 mbar).

Pervaporation of the non-diluted multicomponent mixture was shown to be strongly influenced by interactions between the permeants and the membrane. Investigation of these interactions contributed to the understanding of the mass transport mechanism of this mixture. Overall, high fluxes were obtained, but small differences between the fastest permeating species were found. The fastest permeating species was ethanol, ethyl acetate or 1-methoxy-2-propanol depending on the feed composition.