Leak growth mechanism in composite Pd membranes prepared by the electroless deposition method

Guazzone, Federico; Hua, Yi

doi:10.1002/aic.11397

Cited by 83 publications

(52 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The He leak growth rates for N_03 and N_02 were 7*10 -6 and 3*10 -6 m 3 /(m 2 *h)/h respectively making the growth rate of N_02 and N_03 more than an order of magnitude less than the rate reported previously for pure Pd membranes. Indeed, the leak growth rates at 500°C of N_02 and N_03 were even slightly less than the growth rates measured at 450°C for pure Pd membranes [37].…”

Section: Pd/cu Membrane Fabrication and Characterizationmentioning

confidence: 66%

“…Since the majority of the membranes tested by Guazzone and Ma [37] were pure Pd, it appeared that the presence of Cu increased the leak stability of N_02 and N_03.…”

Section: Pd/cu Membrane Fabrication and Characterizationmentioning

confidence: 99%

“…Guazzone et al [47] observed that microstrains and stresses in the deposit released upon heating caused pinhole formation and growth. Indeed, past research [37,39,47] indicated that the He leak of electroless deposited Pd membranes increased over the time period of the membrane characterization.…”

Section: Ppm H 2 S/h 2 At 450ºcmentioning

confidence: 99%

See 2 more Smart Citations

Sulfur Tolerant Pd/Cu and Pd/Au Alloy Membranes for H2 Separation with High Pressure CO2 for Sequestration

Hua¹,

Pomerantz²,

Chen³

2008

View full text Add to dashboard Cite

The effect of H 2 S poisoning on Pd, Pd/Cu, and Pd/Au alloy composite membranes prepared by the electroless deposition method on porous Inconel supports was investigated to provide a fundamental understanding of the durability and preparation of sulfur tolerant membranes. X-ray photoelectron spectroscopy (XPS) studies showed that the exposure of pure Pd to 50 ppm H 2 S/H 2 mixtures caused bulk sulfide formation at lower temperatures and surface sulfide formation at higher temperatures. Lower temperatures, longer exposure times, and higher H 2 S concentrations resulted in a higher degree of sulfidation. In a Pd membrane, the bulk sulfide formation caused a drastic irrecoverable H 2 permeance decline and an irreparable loss in selectivity.Pd/Cu and Pd/Au alloy membranes exhibited permeance declines due to surface sulfide formation upon exposure to 50 ppm H 2 S/H 2 gas mixtures. However in contrast to the pure Pd membrane, the permeances of the Pd/Cu and Pd/Au alloy membranes were mostly recovered in pure H 2 and the selectivity of the Pd alloy layers remained essentially intact throughout the characterization in H 2 , He and H 2 S/H 2 mixtures which lasted several thousand hours. The amount of irreversible sulfur poisoning decreased with increasing temperature due to the exothermicity of H 2 S adsorption. Longer exposure times increased the amount of irreversible poisoning of the Pd/Cu membrane but not the Pd/Au membrane.Pd/Au coupon studies of the galvanic displacement method showed that higher Au 3+ concentrations, lower pH values, higher bath temperatures and stirring the bath at a rate of 200 rpm yielded faster displacement rates, more uniform depositions, and a higher Au content within the layers. While 400ºC was found to be sufficient to form a Pd/Au alloy

show abstract

Section: Pd/cu Membrane Fabrication and Characterizationmentioning

confidence: 66%

“…Since the majority of the membranes tested by Guazzone and Ma [37] were pure Pd, it appeared that the presence of Cu increased the leak stability of N_02 and N_03.…”

Section: Pd/cu Membrane Fabrication and Characterizationmentioning

confidence: 99%

See 1 more Smart Citation

Sulfur Tolerant Pd/Cu and Pd/Au Alloy Membranes for H2 Separation with High Pressure CO2 for Sequestration

Hua¹,

Pomerantz²,

Chen³

2008

View full text Add to dashboard Cite

show abstract

“…The maximum membrane temperature, which coincides with the feed inlet temperature (no reaction occurs inside the reactor), is set at 400°C (Guazzone and Ma, 2008;Peters et al, 2009), requiring a waste heat boiler after the WGS. Higher temperature would reduce the membrane surface area, but it would have no impact on system efficiency since the maximum fuel temperature at combustor inlet is set at 350°C.…”

Section: Co 2 Feedingmentioning

confidence: 99%

Techno-economic assessment of two novel feeding systems for a dry-feed gasifier in an IGCC plant with Pd-membranes for CO2 capture

Gazzani¹,

Turi²,

Ghoniem³

et al. 2014

International Journal of Greenhouse Gas Control

View full text Add to dashboard Cite

This study focuses on the application of Pd-based membranes for CO 2 capture in coal fuelled power plants. In particular, membranes are applied to Integrated Gasification Combined Cycle with two innovative feeding systems. In the first feeding system investigated, CO 2 is used both as fuel carrier and back-flushing gas for the candle filters, while in the second case N 2 is the fuel carrier, and CO 2 the back-flushing gas. The latter is investigated because current dry feed technology vents about half of the fuel carrier, which is detrimental for the CO 2 avoidance in the CO 2 case. The hydrogen separation is performed in membrane modules arranged in series; consistently with the IGCC plant layout, most of the hydrogen is separated at the pressure required to fuel the gas turbine. Furthermore, about 10% of the overall hydrogen permeated is separated at ambient pressure and used to post-fire the heat recovery steam generator. This layout significantly reduces membrane surface area while keeping low efficiency penalties.The resulting net electric efficiency is higher for both feeding systems, about 39%, compared to 36% of the reference Selexol-based capture plant. The CO 2 avoidance depends on the type of feeding system adopted, and its amount of vented gas; it ranges from 60% to 98%. From the economic point of view, membrane costs are significant and shares about 20% of the overall plant cost. This leads in the more optimistic case to a CO 2 avoidance cost of 35 €/t CO2 , which is slightly lower than the reference case.

show abstract

“…Composite Pd membranes also suffer from a small window of operation with respect to temperature. Below 300 °C phase separation and hydrogen embrittlement occurs, while thin composite Pd films can reconstruct at temperatures >450 °C, limiting durability [61]. The BCC metals (V, Ta, Nb) have much greater theoretical permeability for hydrogen than Pd [62], but are unable to dissociate H 2 .…”

Section: Introductionmentioning

confidence: 99%

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

Way¹,

Wolden²

2013

View full text Add to dashboard Cite

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

show abstract

Leak growth mechanism in composite Pd membranes prepared by the electroless deposition method

Cited by 83 publications

References 21 publications

Sulfur Tolerant Pd/Cu and Pd/Au Alloy Membranes for H2 Separation with High Pressure CO2 for Sequestration

Sulfur Tolerant Pd/Cu and Pd/Au Alloy Membranes for H2 Separation with High Pressure CO2 for Sequestration

Techno-economic assessment of two novel feeding systems for a dry-feed gasifier in an IGCC plant with Pd-membranes for CO2 capture

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

Contact Info

Product

Resources

About