Palladium alloy membranes hydrogen separation

Roa F, Way D, Paglieri SN. Process for preparing palladium alloy composition membranes for use in hydrogen separation, palladium alloy composite membranes and products incorporation or made from the membranes. United States Patent 8119205 2012. 

A wide variety of materials (polymers, zeolites, ceramics and metals) have been reported for various gas separation applieations. Polymeric membranes are the only ones whieh are extensively used. Inorganic and metallic membranes have limited applieations in the gas separations. Palladium alloy membranes have been applied for the purifieation of hydrogen and mixed metal oxide membranes have been developed for high temperature air separations by ion transport meehanism. The state-of-the-art of gas separation membrane materials is presented in a reeent review article. ... 

Hopkins, S., High-Performance, Durable, Palladium-Alloy Membrane for Hydrogen Separation and Purification, Proceedings of 2007 U.S. DOE Hydrogen Annual Merit Review Meeting, Arlington, VA, May 2007. 

Ma, Y., Mardilovich, I.P. and Engwall, E.E. (2003) Thin composite palladium and palladium/alloy membranes for hydrogen separation. Annals of the New York Academy of Sciences, 984, 346—360. 

The key problem of the cross-flow reactor is not how to construct an effective separation of the two flowing phases. It is instead connected with how to design the porosity and location of the catalytic active zones of the separating walls so that the transport resistance across the wall does not limit the conversion and the selectivity of the chemical reactions. Palladium-alloy membranes, or thin films of these alloys on porous ceramic tubs, seem to have the potential to be good solutions of the separating-wall problem for cross-flow reactors used for hydrogenation reactions. 

Evans, J., Harris, I.R., and Ross, D.K., A proposed method of hydrogen isotope separation using palladium alloy membranes, J. Less-Comm. Met., 89, 407, 1983. 

Darling, A. S., Hydrogen separtaion by diffusion through palladium alloy membranes. Symposium on the less common means of separation. Institution of chemical engineers 1963. 

Ma YH, Engwall EE, Mardilovich IP. Composite palladium and palladium-alloy membranes for high temperature hydrogen separations. ACS Fuel Chem Div Prepr. 2003 48(1) 333. 

S. Tosti, V. Violante, Numerical approach for a study of the hydrogen isotopes separation by palladium alloy membranes. Fusion Eng. Des. 1998,... 

Conventional production of vitamin K consists of four steps hydrogenation of 2-methylnaphthoquinone-l,4 to 2-methylnaphthohydroquinone-l,4 in a solvent in the presence of Raney nickel separation of the product from the catalyst by filtration evaporation of the solvent and boiling with acetic anhydride. Because the anhydride is highly corrosive, it tends to attack the nickel, and hence complete separation of the catalyst is necessary. On the other hand, use of a palladium alloy membrane reactor eliminates corrosion and makes it possible to complete the whole process in a single step (Gryaznov et al., 1986). The overall reaction is... 

Hatlevik, S. K. Gade, M. K. Keeling, P. M. Thoen, A. P. Davidson and J. D. Way, Palladium and palladium alloy membranes for hydrogen separation and production History, fabrication strategies, and current performance, Sep. Purif. TechnoL, 2010, 73, 59-64. 

Tokyo Gas Co., Ltd. (TGC) has developed a 40 Nm /h-class membrane reformer system with the world s highest efficiency (a value of 81.4%). The company has demonstrated the use of the hydrogen produced to refuel fuel cell vehicles (FCV), together with CO2 capture at the hydrogen station. An advanced hydrogen separation membrane module consisting of a palladium alloy membrane on a structured porous catalyst, which can be used to produce a membrane reformer that is more compact and less expensive, has also been developed. This chapter introduces the development of these two membrane reformer technologies. 

Okazaki, J., Ikeda, T., Tanaka, D. A. P., Sato, K., Suzuki, T. M., Mizukami, F. (2011). An investigation of thermal stability of thin palladium—silver alloy membranes for high temperature hydrogen separation. Journal of Membrane Science, 366(1), 212—219. 

Pinacci P, Broglia M., RadaeUi M., Bottino A., Capannelli G. and Comite A., Development of Palladium Alloy Membranes for Hydrogen Separation from Synthesis Gas in Membrane Reactors, Proc. of 3 Int. Conf on Clean Cod Technologies for our Future, Caghari (I), May 15-17,2007. 

The cost of Pd-alloy membranes used for hydrogen separation may be reduced by depositing a thin Pd-alloy film on a suitable porous substrate to form a composite membrane. Almost all of the Pd-alloy membrane development efforts are, thus, focused on preparing thin yet defect-free Pd-alloy composite membranes (e.g., Hopkins, 2007 Coulter, 2007 Delft et al., 2005 Damle et al., 2005 Mardilovich et al., 2002). A detailed review of the Pd-alloy membrane research has been prepared by Paglieri and Way (2002) with an extensive bibliography of the palladium membrane research to date. An updated review has been recently prepared by Collot (2003) and Paglieri (2006). 

An integrated proof-of-concept (POC) size fluidized-bed methane reformer with embedded palladium membrane modules for simultaneous hydrogen separation is being developed for demonstration (Tamhankar et al., 2007). The membrane modules will use two 6 in. X 11 in. Pd-alloy membrane foils, 25-pm thick, supported on a porous support. The developmental fluidized-bed reactor will house a total of five (5) membrane modules with a total membrane area of about 0.43 m2 and is scheduled for demonstration by September 2007. 

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