Synthesis of a self-supporting faujasite zeolite membrane using geopolymer gel for separation of alcohol/water mixture

Abstract A self-supporting faujasite (FAU) zeolite membrane was synthesized by in situ hydrothermal method at 90 °C for 15 h from a Na 2 O–3SiO 2 –Al 2 O 3 geopolymer gel that was prepared from the raw materials metakaolin and sodium silicate solutions (molar ratio of SiO 2 /Na 2 O=1). The results revealed that the BET surface area and the compressive strength of the FAU zeolite membrane were 63.31 m 2 /g and 19.6 MPa, respectively. The pervaporation study of its separation performance in a C 2 H 5 OH/H 2 O mixture demonstrated that the permeate flux and separation factor can reach 1.41 kg/(h·m 2 ) and 16.8, respectively, at a feed temperature of 50 °C and an alcohol composition of 70 wt%, making it an effective pervaporation membrane for the separation of alcohol/water mixtures.