Mass-production of tubular NaY zeolite membranes for industrial purpose and their application to ethanol dehydration by vapor permeation

Abstract

A fabrication method for tubular NaY zeolite membranes with 80 cm long for industrial purpose has been applied in mass-production to synthesize 99 membrane samples using two types of synthetic solutions with Al 2O 3:SiO 2:Na 2O:H 2O = 1:10:14:800 and = 1:20:14:1000. Sufficient reproducibility for industrial purpose with high membrane performance in mass-production were observed by pervaporation at 75 °C in a feed mixture of water(10 wt.%)/ethanol(90 wt.%), resulting in the average flux (1 − σ) and separation factor of 8.1 kg m −2 h −1 (1.5) and 220 for the SiO 2-rich synthetic solution and those of 9.9 kg m −2 h −1 (1.3) and 190 for the SiO 2-poor solution, respectively. Dehydration of hydrous ethanol by vapor permeation for the present membranes was studied at 90–110 °C to investigate an applicability of these membranes to ethanol purification. The ethanol products with concentration up to 98.5 wt.% and with 96.1 wt.% could be obtained at 110 °C by production rates at 5 kg h −1 and 20 kg h −1, respectively. It is also confirmed that concentration polarization could limit the permeation fluxes through the present high-performance membranes for the feed flow rates at 5.5–22 kg h −1 with the Reynolds number of 5000–20,000.