Performance of sodium A zeolite membranes synthesized via microwave and autoclave techniques for water–ethanol separation: Recycle-continuous pervaporation process

The performance of sodium A (NaA) zeolite membranes with a surface area of 4.91 cm2, synthesized on an alumina support via microwaving (MW) and autoclaving (AC, or conventional heating) using the recycle-continuous pervaporation of a water–ethanol mixture (10:90 vol.%), was studied. It was found that the process could produce ethanol having a concentration close to 100% (higher than 99.5%) after passing the mixture through the membrane for 120–140 h. The time-dependence separation factor and the total water flux were 3350–6050 and 0.4–1.0 kg/m2/h, respectively. The time-dependence separation factor of this process was increased to higher than 10,000 when the percentage of ethanol at the retentate side was higher than 98%. The overall results showed good stability of the membranes for the water–ethanol separation.

[1]  Prabir K. Dutta,et al.  Handbook of Zeolite Science and Technology , 2003 .

[2]  H. Kita,et al.  Synthesis of a zeolite NaA membrane for pervaporation of water/organic liquid mixtures , 1995 .

[3]  Dibakar Bhattacharyya,et al.  Pervaporation of alcohol–water and dimethylformamide–water mixtures using hydrophilic zeolite NaA membranes: mechanisms and experimental results , 2000 .

[4]  Chunshan Song,et al.  Microwave-assisted hydrothermal synthesis of hydroxy-sodalite zeolite membrane , 2004 .

[5]  Yanshuo Li,et al.  Microwave synthesis of LTA zeolite membranes without seeding , 2006 .

[6]  Robert Y. M. Huang,et al.  Pervaporation dehydration of ethanol–water mixtures with chitosan/hydroxyethylcellulose (CS/HEC) composite membranes: I. Effect of operating conditions , 2002 .

[7]  Tonghua Wang,et al.  Novel tubular composite carbon-zeolite membranes , 2004 .

[8]  A. Huang,et al.  Synthesis and pervaporation properties of NaA zeolite membranes prepared with vacuum-assisted method , 2007 .

[9]  S. Wongkasemjit,et al.  Preparation of uniform and nano-sized NaA zeolite using silatrane and alumatrane precursors , 2006 .

[10]  Hyeryeong Lee,et al.  Pervaporation of an aqueous ethanol solution through hydrophilic zeolite membranes , 2006 .

[11]  Shiro Ikeda,et al.  Dehydrating performance of commercial LTA zeolite membranes and application to fuel grade bio-ethanol production by hybrid distillation/vapor permeation process , 2008 .

[12]  Y. S. Lin,et al.  Synthesis and properties of A-type zeolite membranes by secondary growth method with vacuum seeding , 2004 .

[13]  Sudipta Bhattacharya,et al.  Concentration polarization, separation factor, and Peclet number in membrane processes , 1997 .

[14]  Jan Degrève,et al.  Pervaporation of water¿alcohol mixtures and acetic acid¿water mixtures , 2005 .

[15]  S. Wongkasemjit,et al.  Effects of synthesis parameters on zeolite membrane formation and performance by microwave technique , 2007 .

[16]  Yanshuo Li,et al.  Formation mechanism of microwave synthesized LTA zeolite membranes , 2006 .

[17]  S. Nakao,et al.  Ethanol/water transport through silicalite membranes , 1998 .

[18]  H. Kita,et al.  Tubular-type pervaporation module with zeolite NaA membrane☆ , 1997 .

[19]  H. M. Veen,et al.  Dewatering of organics by pervaporation with silica membranes , 2001 .

[20]  Yanshuo Li,et al.  Hydrothermal stability of LTA zeolite membranes in pervaporation , 2007 .