Effect of Operating Variables on the Pervaporation of Ethanol Produced by Lignocellulosic Residue

The separation of organic components has become increasingly important as one of the applications of pervaporation membranes. This interest is due to their application in areas that include the recovery of ethanol from a fermentation broth as a lower-energy-cost alternative to classical separation processes such as distillation. The present work seeks to evaluate the separation of ethanol produced from banana waste (unused fruit and pulp) using pervaporation. Different operating conditions, such as flow rate, temperature, feed composition and permeate pressure were studied in commercial hydrophobic polydimethylsiloxane (PDMS) membranes. The experiments were compared to a standard solution (ethanol/water) to determine differences in the results due to the presence of fermentation by products. As expected, the best results for the recovery of ethanol were obtained at lower feed and the flux increases with increasing ethanol concentration in the feed, whereas the selectivity decreases. When the evaluated characteristics were compared with the fermentation broth, the following increases were observed: a 20% increase in the enrichment factor and a 75% increase in ethanol concentration in the permeate. The results are considered to be promising and indicate the feasibility of using pervaporation in the production of bioethanol from banana waste.