Preparation and characterization of zeolite membrane for bioethanol purification

Abstract

The use of bioethanol as an alternative fuel with a purity of more than 99.5% wt has prompted research on bioethanol purification. One of the promising methods used for bioethanol purification is pervaporation. This research is aimed to prepare and characterize zeolite membranes for pervaporation. The membrane preparation consisted of two stages, namely support layer preparation and zeolite deposition on the sup-port. In support preparation, α-alumina and kaolin with specific composition (50:30; 40:40; 50:30) was mixed with additives and water. After pugging and aging process, the mixture was extruded into a tubular shape. The tube was then calcined at temperature of 1250 °C for 3 hours. After that, zeolite 4A was deposit-ed on the tubes using clear solution made of 10 %wt zeolite and 90 %wt water and heated at temperature of 80 °C for 3 hours. Furthermore, the resulting zeolite membrane was washed with deionized water for 5 minutes and dried in oven at temperature of 100 °C for 24 hours. Characterization of zeolite membranes in-cluded mechanical strength test, XRD, and SEM. In the mechanical strength test, the membrane sample with α-alumina:kaolin = 50:30 (membrane A) had the highest mechanical strength of 46.65 N/mm2. Result of the XRD analysis for the membrane A indicated that mullite and corundum phases were formed, where mullite phase was more dominant. Meanwhile the result of SEM analysis showed that zeolite crystals have been formed and covered the pores support, but the deposition of zeolite has not been optimal yet. The etha-nol product concentration and permeate flux were influenced by the feed temperature, feed concentration and permeate pressure. The performance examination for bioethanol purification showed that the mem-brane could increase the purity of bioethanol with maximum purity was 98.5% wt. © 2013 BCREC UNDIP.