Separation of ethanol from water by pervaporation using mixed matrix copolymer membranes

• Copolymer membranes were prepared from butyl acrylate and styrene monomer.
• Mixed matrix membranes were also prepared by in situ incorporation of nano clay.
• The organo nano clay filled membranes showed good flux and ethanol selectivity.
• Sorption, permeation and diffusion characteristics of the membranes were studied.

Several ethanol selective mixed matrix membranes were prepared from the copolymer of butyl acrylate and styrene and an organophilic nano size clay filler. The clay was incorporated in the polymer during its synthesis from the butyl acrylate and styrene monomer by emulsion polymerization in water. These membranes were characterized and used for the separation of 2.5–15 wt% ethanols from water by pervaporation. The mixed matrix copolymer membrane containing 2% (wt% of total polymer) clay was observed to yield the best result, i.e., a flux of 0.34 kg/m2 h and an ethanol selectivity of 26.4 at 30 °C for 5 wt% ethanol in water. The permeability, intrinsic membrane selectivity and concentration average diffusion coefficients of the solvents were also determined.