The relationship between intermetallic diffusion and flux decline in composite-metal membranes: implications for achieving long membrane lifetime

Edlund, David; McCarthy, J.M.

doi:10.1016/0376-7388(95)00110-x

Cited by 135 publications

(55 citation statements)

References 9 publications

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“…In fact, the hydrogen fl ux tends to improve slightly with time when held at high temperature, possibly due to the reduction or removal of trace amounts of impurities that may adsorb during exposure to the atmosphere between fabrication and testing. By comparison, a palladium-coated vanadium membrane would be expected to lose 50% of its hydrogen permeability within 90 minutes of exposure to hydrogen at 700 ° C. [ 19 ] This indicates that the carbide catalyst is not reduced to metallic molybdenum which would be expected to alloy with the bulk vanadium.…”

Section: Doi: 101002/adma201100931mentioning

confidence: 98%

Dense Carbide/Metal Composite Membranes for Hydrogen Separations Without Platinum Group Metals

et al. 2011

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Section: Doi: 101002/adma201100931mentioning

confidence: 98%

Dense Carbide/Metal Composite Membranes for Hydrogen Separations Without Platinum Group Metals

et al. 2011

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“…Other gases such as CO and H 2 O can also be detrimental to long-term membrane performance. The highest measured permeabilities of these materials are of the order of 10 -9 to 10 -8 mol H 2 m -1 s -1 Pa -n , where typically n = 0.5 [104][105][106].…”

Section: Comparison With Metalsmentioning

confidence: 99%

Dense Ceramic Membranes for Hydrogen Separation

Norby

Haugsrud

2006

Nonporous Inorganic Membranes

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“…In fact, the hydrogen flux tends to improve slightly with time when held at high temperature, possibly due to slow reduction of trace amounts of molybdenum oxides formed by exposure to the atmosphere between fabrication and testing. By comparison, a palladium-coated vanadium membrane would be expected to lose 50% of its hydrogen permeability within 90 minutes of exposure to hydrogen at 700 °C [58]. This indicates that the carbide catalyst is not reduced to metallic molybdenum which would be expected to alloy with the bulk vanadium.…”

Section: Resultsmentioning

confidence: 99%

Nanoporous, Metal Carbide, Surface Diffusion Membranes for High Temperature Hydrogen Separations

Way¹,

Wolden²

2013

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Colorado School of Mines (CSM) developed high temperature, hydrogen permeable membranes that contain no platinum group metals with the goal of separating hydrogen from gas mixtures representative of gasification of carbon feedstocks such as coal or biomass in order to meet DOE NETL 2015 hydrogen membrane performance targets. We employed a dual synthesis strategy centered on transition metal carbides. In the first approach, novel, high temperature, surface diffusion membranes based on nanoporous Mo 2 C were fabricated on ceramic supports. These were produced in a two step process that consisted of molybdenum oxide deposition followed by thermal carburization. Our best Mo 2 C surface diffusion membrane achieved a pure hydrogen flux of 367 SCFH/ft 2 at a feed pressure of only 20 psig. The highest H 2 /N 2 selectivity obtained with this approach was 4.9. A transport model using "dusty gas" theory was derived to describe the hydrogen transport in the Mo 2 C coated, surface diffusion membranes. The second class of membranes developed were dense metal foils of BCC metals such as vanadium coated with thin (< 60 nm) Mo 2 C catalyst layers. We have fabricated a Mo 2 C/V composite membrane that in pure gas testing delivered a H 2 flux of 238 SCFH/ft 2 at 600 °C and 100 psig, with no detectable He permeance. This exceeds the 2010 DOE Target flux. This flux is 2.8 times that of pure Pd at the same membrane thickness and test conditions and over 79% of the 2015 flux target. In mixed gas testing we achieved a permeate purity of ≥99.99%, satisfying the permeate purity milestone, but the hydrogen permeance was low, ~0.2 SCFH/ft 2 .psi. However, during testing of a Mo 2 C coated Pd alloy membrane with DOE 1 feed gas mixture a hydrogen permeance of >2 SCFH/ft 2 .psi was obtained which was stable during the entire test, meeting the permeance associated with the 2010 DOE target flux. Lastly, the Mo 2 C/V composite membranes were shown to be stable for at least 168 hours = one week, including cycling at high temperature and alternating He/H 2 exposure.4

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The relationship between intermetallic diffusion and flux decline in composite-metal membranes: implications for achieving long membrane lifetime

Cited by 135 publications

References 9 publications

Dense Carbide/Metal Composite Membranes for Hydrogen Separations Without Platinum Group Metals

Dense Carbide/Metal Composite Membranes for Hydrogen Separations Without Platinum Group Metals

Dense Ceramic Membranes for Hydrogen Separation

Nanoporous, Metal Carbide, Surface Diffusion Membranes for High Temperature Hydrogen Separations

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