Browsing by Keyword "Membrane preparation"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item N2, He and CO2 diffusion mechanism through nanoporous YSZ/γ-Al2O3 layers and their use in a pore-filled membrane for hydrogen membrane reactors(2016-06-01) Arratibel, Alba; Astobieta, Uxue; Pacheco Tanaka, David Alfredo; Van Sint Annaland, Martin; Gallucci, Fausto; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSNanoporous ceramic supports for pore filled membranes were prepared on ceramic supports (α-Al2O3) with pore size of 100 nm by adding additional layers with different proportions of YSZ/γ-Al2O3 (ranging from 50% to 90% of YSZ) by dip-coating and the effect of different parameters in the preparation method have been investigated. The diffusion mechanisms of N2, He and CO2 through the supported nanoporous layers have been studied in detail with permeation measurements at a temperature range of 50-400°C and pressure difference of 30-100 kPa. It was observed that as the amount of γ-Al2O3 in the nanoporous layers increases, the adsorption of CO2 is favored at low temperatures and pressures. Finally, a pore-filled Pd/YSZ/γ-Al2O3 (60 wt%YSZ-40 wt. γ-Al2O3) membrane was successfully prepared and its permeation performance was tested over 900 h at 500 and 550 C, showing relatively low ideal H2/N2 perm-selectivity of about 50 due to low hydrogen flux.Item Unravelling the transport mechanism of pore-filled membranes for hydrogen separation(2018-09-12) Arratibel, Alba; Pacheco Tanaka, David A.; Slater, Thomas J.A.; Burnett, Timothy L.; van Sint Annaland, Martin; Gallucci, Fausto; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe permeation characteristics of palladium pore filled (PF) membranes have been investigated with gas permeation and structural characterization of the membranes. PF membranes have been prepared by filling with Pd the nanoporous γ-Al2O3/YSZ (or pure YSZ) layer supported onto porous α-Al2O3 and ZrO2. The number of nanoporous layers and the applied vacuum level during the electroless plating process have been studied. Gas permeation properties of the PF membranes have been determined in a temperature range of 300-550 °C. The measured hydrogen permeances have been found to be lower than previously reported for similar membranes. It has been found that the hydrogen fluxes do not depend on the thickness of the nanoporous layers (γ-Al2O3/YSZ or pure YSZ) or on the vacuum pump employed for filling with Pd. The physicochemical characterization performed showed that the palladium deposited does not form a percolated network across the mesoporous layer(s), leading to low hydrogen permeances and thus low H2/N2 perm-selectivities.