화학공학소재연구정보센터
Journal of Membrane Science, Vol.310, No.1-2, 161-173, 2008
Synthesis of industrial scale NaY zeolite membranes and ethanol permeating performance in pervaporation and vapor permeation up to 130 degrees C and 570 kPa
NaY zeolite tubular membranes in an industrial scale of 80 cm long were synthesized on monolayer and asymmetric porous supports. The quality of synthesized membranes were evaluated by pervaporation (PV) experiments in 80 em long at 75 degrees C in a mixture of water (10 wt.%)/ethanol (90 wt.%), resulting in higher permeation fluxes of 5.1 kg m(-2) h(-1) in the monolayer type membrane and of 9.1-10.1 kg m(-2) h(-1) in the asymmetric-type membranes, respectively. The uniformity with small performance fluctuation in longitudinal direction of the membranes were observed by PV for 10-12 cm long samples at 50 degrees C in a mixture of methanol (10 wt.%)/MTBE (90 wt.%). The ethanol single component permeation experiments in PV and vapor permeation (VP) Lip to 130 degrees C and 570 kPa were performed to determine the relations between the ethanol flux and the ethanol pressure difference across the membrane which is represented by permeance (171, mol m(-2) s(-1) Pa-1) for estimate of potential of ethanol extraction through the present NaY zeolite membranes applying feasible studies. Results indicate that (1) the permeation fluxes are linearly proportional to the driving force of vapor pressure for each sample in VP and PV. The permeances through an asymmetric support type membrane were rather constant of 0.6-1.2 x 10(-7) mol m(-2) s(-1) Pa-1 in the wide temperature range of 90-130 degrees C in PV and VP, indicating that the ethanol permeances have weak temperature dependency with the feed at the saturated vapor pressure. The results of superheating VP experiments showed that ethanol permeation fluxes are increased with increasing of the degree of superheating at a given constant feed vapor pressure. The ethanol permeances are increased with increasing of temperature at a given feed vapor pressure. The Superheating VP could be a feasible process in industry. (C) 2007 Elsevier B.V. All rights reserved.