Dense membranes for hydrogen separation and

Chapter 6 Dense Membranes for Hydrogen Separation and Purification..147... 

Tong, J., Matsumura, Y., Suda, H., and Haraya, K. Thin and dense Pd/Ce02/MPSS composite membrane for hydrogen separation and steam reforming of methane. Separation and Purification Technology, 2005, 46 (1-2), 1. 

The separation layer may be dense (non-porous), such as Pd or Pd-alloy membranes for hydrogen separation and mixed (electronic, ionic) conducting oxide membranes for oxygen separation, or porous, such as metal oxides, silicalite, or zeolite membranes. Inorganic membranes are generally named for this separation layer, since it determines the properties and application of the membrane. The flux and selectivity of inorganic membranes are mainly determined by the quality of the separation layer, which is required to be defect-free and as thin as possible. 

Balachandran, U., T.H. Lee, S. Wang, G. Zhang, and S.E. Dorris, Current Status of Dense Ceramic Membranes for hydrogen Separation, 27th International Technical Conference on Coal Utilization and Fuel Systems, Clearwater, FL, March 2002. 

Dorris, S.E., T.H. Lee, S. Wang, J.J. Picciolo, J.T. Dusek, and U. Balachandran, Dense Cermet Membranes for Hydrogen Separation, 19th Annual International Pittsburgh Coal Conference, Pittsburgh,... 

Dense palladium membranes are the most investigated membranes for hydrogen separation. They are investigated by several research groups as the group of Gryaznov [26-28] and the group of Uemiya and Kikuchi [29,30],... 

A. Li, W. Liang and R. Hughes, Fabrication of Dense Palladium Composite Membranes for Hydrogen Separation, Calal. Today, 56, 45-51 (2000). 

Balachandran U, Ma B, Lee T, Chen L, Song SJ, Dorris SE. Development of dense ceramic membranes for hydrogen production and separation. Proceedings of the lClM-8, Cindnnati, OH, 2004, pp. 163-6. 

On the other hand, if a dense supported membrane (as Pd-based membranes for hydrogen separation) is assembled, a stringent temperature threshold (T > 500 °C) has to be respect to guarantee a proper selective layer-support adherence. For IMR, this leads to a limit for reaction operating conditions, as well. In SMR, reaction and separation operating conditions can be defined, and optimized, separately, leading to crucial performance benefits. 

Li, A., Liang, W. and Hughes, R. (2000) Eabrication of dense palladitun composite membranes for hydrogen separation. Catal. Today, 56, 45-51. 

BalachandrianU.,LeeT. H.,Chen L.,Song S. J. and Dorris S.E.,Dense Ceramic-Metal Composite Membranes for Hydrogen Separation, Proc. 9 Int. Conf. on Inorganic membranes, LiUehammer (Norway), June 25-29,2006. 

There are essentially four different types of membranes, or semipermeable barriers, which have either been commercialized for hydrogen separations or are being proposed for development and commercialization. They are polymeric membranes, porous (ceramic, carbon, metal) membranes, dense metal membranes, and ion-conductive membranes (see Table 8.1). Of these, only the polymeric membranes have seen significant commercialization, although dense metal membranes have been used for commercial applications in selected niche markets. Commercial polymeric membranes may be further classified as either asymmetric (a single polymer composition in which the thin, dense permselective layer covers a porous, but thick, layer) or composite (a thick, porous layer covered by a thin, dense permselective layer composed of a different polymer composition).2... 

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