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Effect of synthesis conditions on performance of a hydrogen selective nano-composite ceramic membrane

Amanipour, M ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1016/j.ijhydene.2012.07.085
  3. Publisher: Elsevier , 2012
  4. Abstract:
  5. A hydrogen-selective nano-composite ceramic membrane was prepared by depositing a dense layer composed of SiO2 and Al2O 3 on top of a graded multilayer substrate using co-current chemical vapor deposition (CVD) method. The multilayer substrate was made by dip-coating a macroporous α-alumina tubular support by a series of boehmite solutions to get a graded structure. Using DLS analysis, it was concluded that decreasing hydrolysis time and increasing acid concentration lead to smaller particle size of boehmite sols. XRD analysis was carried out to investigate the structure of intermediate layer and an optimized calcination temperature of 973 K was obtained. SEM images indicated the formation of a graded membrane with a porous intermediate layer having a thickness of about 2 μm and a dense top selective layer with a thickness of 80-100 nm. Permeation tests showed that H2 permeance flux decreased from 5 × 10-5 mol m-2 s-1 Pa-1 for a fresh substrate to 6.30 × 10 -7 mol m-2 s-1 Pa-1 after 6 h of deposition, but H2 selectivity over N2 increased considerably from 5.6 to 203
  6. Keywords:
  7. Nano-composite membrane ; Permeance flux ; Acid concentrations ; Boehmite sol ; Calcination temperature ; Chemical vapor deposition methods ; CVD method ; Dense layer ; Dip coating ; Graded multilayers ; Graded structure ; Intermediate layers ; Macroporous ; Multilayer substrate ; Permeation test ; Selective layers ; SEM image ; Synthesis conditions ; XRD analysis ; Alumina ; Calcination ; Ceramic membranes ; Composite membranes ; Hydrogen ; Multilayers ; Nanocomposites ; Sols ; Chemical vapor deposition
  8. Source: International Journal of Hydrogen Energy ; Volume 37, Issue 20 , October , 2012 , Pages 15359-15366 ; 03603199 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0360319912017156