Direction of Carbon Membrane Development

As demonstrated, CMS membranes have the potential to technically compete with polymer membranes and to advance the use of membranes in new and challenging separations. Traditionally, the majority of CMS research has dealt with synthesizing new CMS materials using (1) new polymer precursors, (2) new pyrolysis techniques, or (3) modifying existing precursors and/or CMS membranes. Unfortunately, there arc stiU only a limited number of studies that address the relalionship between the polymer precursor or formation parameters and the resulting CMS membranes. This will be very important for systematic development of these materials for new separations such as olefin/paraBin. 

The authors gratefully acknowledge the financial support of the Department of Energy under grant number DE-FG02-04ER15510 and the Georgia Research Alliance. The authors would also like to thank John Perry and Melissa Zubris-Williams for then-helpful comments. 

Acharya, M., Raich, B. A., Foley, H. C., Harold, M. R, and Lerou, J. J. (1997). Metal-supported carbogenic molecular sieve membranes Synthesis and applications. Ind. Eng. Chem. Res. 36, 2924-2930. 

Acharya, M., and Foley, H. C. (1999). Spray-coating of nanoporous carbon membranes for air separation. J. Membr. Sci. 161, 1-5. 

Langsam, M., Rao, M. B., and Sircar, S. (1997). Multicomponent gas separation by selective surface flow (SSF) and poly-trimethylpropyne (PTMSP) membranes. J. Membr. Sci. 123, 17-25. 

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Current Research and Future Direction of Carbon Membrane Development for Gas Separation... 

The concept of the reversed fuel cell, as shown schematically, consists of two parts. One is the already discussed direct oxidation fuel cell. The other consists of an electrochemical cell consisting of a membrane electrode assembly where the anode comprises Pt/C (or related) catalysts and the cathode, various metal catalysts on carbon. The membrane used is the new proton-conducting PEM-type membrane we developed, which minimizes crossover. 

A number of different methods exist for the production of catalyst layers [97-102]. They use variations in composition (contents of carbon, Pt, PFSI, PTFE), particle sizes and pds of highly porous carbon, material properties (e.g., the equivalent weight of the PFSI) as well as production techniques (sintering, hot pressing, application of the catalyst layer to the membrane or to the gas-diffusion layer, GDL) in order to improve the performance. The major goal of electrode development is the reduction of Pt and PFSI contents, which account for substantial contributions to the overall costs of a PEFC system. Remarkable progress in this direction has been achieved during the last decade [99, 100], At least on a laboratory scale, the reduction of the Pt content from 4.0 to 0.1 mg cm-2 has been successfully demonstrated. 

The authors intend to make a historic overview of carbon-related membranes in this book. It will cover the development of carbon related membranes and membrane modules from its onset to the latest research on carbon mixed matrix membranes. After the review of the progress in the field, they also intend to show the future direction of R D. 

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