Pervaporation study for different binary mixtures in the esterification system of lactic acid with ethanol

Pervaporation experiments were performed for some binary mixtures involved in the esterification of lactic acid with ethanol: water/ethanol, water/ethyl lactate and water/lactic acid. The effects of feed composition and operating temperature on the membrane performance were analyzed. Two different commercial hydrophilic membranes PERVAP® 2216 and PERVAP® 2201 were tested for the system water/ethanol. PERVAP® 2201 membrane was chosen for further experiments due to its better selectivity towards water. The permeation flux, as well as permeances, was found to increase with water feed concentration. The influence of temperature on the permeation flux can be described by an Arrhenius-type expression. However, not a great influence of temperature on the permeance was found. Separation factor and selectivity were found to depend on water feed concentration but not a clear influence of temperature was found on these two parameters.