Hydrogen separation membranes annual report for FY 2008.

Hydrogen separation membranes annual report for FY 2010.

“…Due to the presence of H 2 S (see Table 1), the flux decreased slowly during test 2a, but it stabilized at a value only ≈10% lower than its initial value. We have reported similar behavior for Argonne's cermet membranes during their exposure to H 2 S concentrations that were not high enough to cause formation of Pd 4 S [4]. During test 2b, the flux also decreased ≈10% from its initial value and then appeared to reach a stable value.…”

“…At 540ºC, the phase boundary appeared at a slightly lower H 2 S concentration for ANL-3e thin film (10-20 ppm) than Pd foil (30-32 ppm). 4. We also monitored the hydrogen flux of an ANL-3e thin film for ≈4 months during exposure to simulated "coal gas" (51% H 2 /31% CO 2 /1% CO/17% He) at 400°C-600°C.…”

“…Hydrogen sulfide (H 2 S) is a particularly corrosive contaminant that HTMs are expected to encounter. When H 2 S reacts with palladium, palladium sulfide (Pd 4 S) forms on the HTM's surface and impedes hydrogen permeation; therefore, the conditions for Pd 4 S-formation largely determine an ANL-3e membrane's tolerance for H 2 S. We determined the temperatures at which Pd 4 S forms in specific feed gases containing 10-73% H 2 and ≈8-400 ppm H 2 S [1] and located the Pd/Pd 4 S phase boundary at 500-600°C in feed gas with 10% H 2 [3,4]. We correlated phase boundary data and hydrogen flux data for Pd foils and ANL-3e disks by measuring hydrogen flux while increasing the H 2 S concentration in the feed gas.…”

Hydrogen separation membranes annual report for FY 2009.

“…Hydrogen sulfide (H 2 S) is a particularly corrosive contaminant that HTMs are expected to encounter. When H 2 S reacts with palladium, palladium sulfide (Pd 4 S) forms on the HTM's surface and impedes hydrogen permeation; therefore, the conditions for Pd 4 S-formation largely determine an ANL-3e membrane's tolerance for H 2 S. We determined the temperatures at which Pd 4 S forms in specific feed gases containing 10-73% H 2 and ≈8-400 ppm H 2 S [1] and located the Pd/Pd 4 S phase boundary at 500-600°C in feed gas with 10% H 2 [3,4]. We correlated phase boundary data and hydrogen flux data for Pd foils and ANL-3e disks by measuring hydrogen flux while increasing the H 2 S concentration in the feed gas.…”