The effect of CO and O2 on hydrogen permeation through a palladium membrane

Amandusson, Helena; Ekedahl, Lars-Gunnar; Dannetun, Helen

doi:10.1016/s0169-4332(99)00357-8

Cited by 125 publications

(56 citation statements)

References 11 publications

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“…Alloying Pd with Ag or Cu is necessary to prevent embrittlement when the membrane is exposed to hydrogen at temperatures below 573K (critical temperature), and at pressures below 2MPa (critical pressure) (2) . Nevertheless, for application in gas mixture, hydrogen permeation through both types of membrane deteriorates, which is caused by the competitive adsorption and resistance by other gas species such as CO, CO 2 , excessive methanol and steam (17)- (18) . The experimental and simulation studies that were conducted at moderate temperature (498-573K) and pressure (0.3-0.5MPa) ranges revealed that the decrease in transmembrane H 2 flux through the Pd/Ag membrane is mainly caused by the competitive adsorption of CO, followed by CH 3 OH, CO 2 and H 2 O (19) .…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on a Compact Methanol Steam Reformer with Pd/Ag Membrane

Faizal

Kuwabara

Kizu

et al. 2012

JTST

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The performance of high purity hydrogen production from methanol for a compact steam reformer with a hydrogen purification membrane was investigated experimentally. A 77 wt.% Pd/23 wt.% Ag membrane with 25µm thickness and CuO/ZnO/ Al 2 O 3 catalyst were used. Heating was performed by a Bunsen type burner using City Gas 13A. The methanol reforming and purification of H 2 were investigated at different reference catalyst zone temperatures (589-689K), pressures at the retentate side (0.2-0.5MPa), steam to methanol(S/C) ratios (0.8-1.6) and reactant flow rates (1.7 ×10 -4 to 4.4 ×10-4 mol/s). The results show that at high reference temperature, high pressure and certain points of the reactant flow rate, the maximum hydrogen permeation rate is obtained when the S/C ratio is around 1. The modified Sieverts' equation which considers the decrease in H 2 concentration at the membrane surface, was proposed. The experimental result was lower than the permeation rate estimated by the modified Sieverts' equation, which is probably caused by the adsorption of non-H 2 species during permeation. It is further demonstrated that the modified Sieverts' equation is able to estimate a more reasonable hydrogen permeation rate in comparison to the estimation by the ordinary Sieverts' equation. In addition, it is shown that the compact methanol steam reformer with a Pd/Ag membrane is able to produce high purity hydrogen with very low CO concentration, which fulfills the Polymer Electrolyte Fuel Cell (PEFC) requirement (<10ppm).

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Section: Introductionmentioning

confidence: 99%

Experimental Study on a Compact Methanol Steam Reformer with Pd/Ag Membrane

Faizal

Kuwabara

Kizu

et al. 2012

JTST

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“…Thus, one can conclude that the reduction in the permeation rate is primarily due to the fact that CO, in particular, blocks the active sites for the dissociation of hydrogen. This is supported by the fact that CO adsorbs less strongly at higher temperatures so that hydrogen permeation is less hindered, resulting in a decreased influence of the additional gases for T = 450°C [39]. The influence of the additional gases like CO on membrane performance is reversible within the temperature range considered.…”

Section: Membrane Testing and Characterizationmentioning

confidence: 89%

Ceramic Supported Capillary Pd Membranes for Hydrogen Separation: Potential and Present Limitations

et al. 2006

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Composite ceramic capillaries coated with thin palladium membranes are developed for the production of CO‐free hydrogen for PEM fuel cells, via alcohol steam reforming. The composite membranes are tested for pure H2 and N2, as well as for synthetic reformate gas. The aim is to develop a heat‐integrated compact membrane reformer for decentralized hydrogen production. In this context, a deep knowledge of the performance, behavior, and necessary treatment of the composite palladium membranes plays a decisive role in process design. The current contribution focuses on the main hurdles met while attempting to exploit the potential of ceramic supported capillary palladium membranes.

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“…The poisoning is due to blocking of hydrogen surface sites by strongly adsorbing species. The extent of the competitive sorption on the H 2 permeation is a function of the temperature and, for low concentration, this is normally a reversible process [53]. The poisoning effect of these components and others, may also become more severe with increasing pressure and decreasing membrane thickness [40].…”

Section: Stability Of Composite Pd Alloy Membranesmentioning

confidence: 99%

“…The poisoning effect of these components and others, may also become more severe with increasing pressure and decreasing membrane thickness [40]. Reduction in permeance in the presence of water has been observed even up to 600 8C [53], while effects of CO adsorption are still important at 400 8C [40]. Hydrocarbon adsorption and C dissolution also negatively affect the permeance, and may cause membrane failure [54].…”

Section: Stability Of Composite Pd Alloy Membranesmentioning

confidence: 99%