Supported membranes hydrogen purification

The separation factors are relatively low and consequently the MR is not able to approach full conversion. With a molecular sieve silica (MSS) or a supported palladium film membrane, an (almost) absolute separation can be obtained (Table 10.1). The MSS membranes however, suffer from a flux/selectivity trade-off meaning that a high separation factor is combined with a relative low flux. Pd membranes do not suffer from this trade-off and can combine an absolute separation factor with very high fluxes. A favorable aspect for zeoHte membranes is their thermal and chemical stability. Pd membranes can become unstable due to impurities like CO, H2S, and carbonaceous deposits, and for the MSS membrane, hydrothermal stability is a major concern [62]. But the performance of the currently used zeolite membranes is insufficient to compete with other inorganic membranes, as was also concluded by Caro et al. [63] for the use of zeolite membranes for hydrogen purification. 

In this work for the first time magnetron sputtering (technologically effective method) was used for the modification of the tubular a-alumina ceramic support of the composite Pd - membrane. This modification could be realized due to the choice of Ni as hydrogen permeable metal instead of y-Al203 layers. It allows to use total effective cross section of the surface porous structure of the support in high temperature process of hydrogen purification by Pd membrane. 

SLM. See hydrogen, purification, membrane, supported liquid SMART. See sulphur, minimization by ART... 

Johnson Matthey Technology Centre, Thin Supported Pd-alloy Membranes for Hydrogen Purification. Report ETSU F/02/00034/REP, 1995. 

Even small amounts of carbon monoxide or other contaminants can poison a fuel cell. Sandia National Laboratories (SNL) is working on developing gas-selective thin film membranes to improve and lower the cost for hydrogen purification. Defect-free aluminosilicate and silicalite zeolite thin films supported on commercially available alpha and gamma alumina disk substrates were developed. In tests using SNL s permeation unit, which can test both pure and mixed gases from room temperature to 250°C, excellent separation values for hydrogen were achieved. 

Deshpande, K., Meldon, J.H., Schmidt, M.A. and Jensen, K.F. (2010) SOI-Supported microdevice for hydrogen purification using palladium-silver membranes. Journal of Microelectromechanical Systems, 19,402 09. 

Deshpande K, Meldon J H, Schmidt M A and Jensen K F (2010), SOI-supported microdevice for hydrogen purification using palladium-silver membranes , J... 

Kirchner, A., Brown, I.W.M., Bowden, M.E., Kemmitt, T. (2007b). Hydrogen Purification using Ultra-thin Palladium Films supported on Porous Anodic Alumina Membranes, in Functional Nanoscale Ceramics for Energy Systems, ed. E. Ivers-Tiffee and S. Barnett (Mater. Res. Soc. Symp. Proc. 1023E, Warrendale, PA, 2007), Paper 1023-JJ09-02. 

Lin, Y.M. and M.H. Rei, Separation of hydrogen from the gas mixture out of a catalytic reformer by using supported palladium membrane, Sep. Purif. Technol., 25,87-95,2001a. 

E. Kikuchi and S. Uemiya, Preparation of supported thin palladium-silver alloy membranes and their characteristics for hydrogen separation. Gas Sep. Purif. 5 261 (1991). 

Uemiya S, Kato W, Uyama A, et al.. Separation of hydrogen from gas mixtures using supported platinum-group metal membranes, Sep. Purif Technol. 2001 22—23 309-317. 

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