Higher-temperature polymer electrolyte membrane fuel cells

Higher-temperature polymer electrolyte membrane fuel cells

permeate, is obviated by grouping plural cassettes into racks, one or more of which may be isolated while permeate production from the remaining racks...

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permeate, is obviated by grouping plural cassettes into racks, one or more of which may be isolated while permeate production from the remaining racks is uninterrupted. Ancillary functions, such as back-pulsing, chemical cleaning and testing for defects in membranes (or integrity testing) in one or more racks may proceed while production of permeate continues. The number of racks in a bank is determined by the period of the overall filtration cycle. The racks make it possible to use automatic on/off valves which open and close more quickly than larger ones. The resulting savings in time, energy and equipment costs (when back-pulsing with permeate) are surprisingly good. In addition, the saving in cost of equipment and the avoidance of wear and tear on pumps, which are intermittently stopped and started, produces unexpected economic benefits. For even greater savings in operating costs, a bank of cassettes, or a bank of racks, may be operated with a gravity-flow system. Patent number." WO 01 / 16030 Inventors: EL. Cote, A.E Janson, S.K. Pedersen, I.S. Low Publication date: 8 March 2001

Semi-permeable membrane film Applicant: Myzee MDI, France The invention concerns a semi-permeable membrane film, which is selectively permeable to water vapour from a solvent in the presence of the corresponding liquid. The membrane layer, advantageously adherent to a support layer to enhance mechanical strength, consists of a polymer material formed from co-polymerized rigid and flexible sequences. These flexible sequences are based on an oligomer, with affinity for the solvent, and in sufficient proportion relative to the rigid sequences to ensure, through its vacant sites, the migration of the solvent molecules through the layer under the effect of the difference in osmotic pressure between its two surfaces. Patent number."W O 01 /15893 Inventors: P. Duhaut, I. Deschamps-Hulak, E. Wittich Publication date." 8 March 2001

humidity gas, and not to increase its contact resistance with the MEA. The fuel cell discussed in this patent includes a conductive separator comprising a metallic base and a conductive resin layer, provided on the metallic base made of a resin, which has a water-repellent, or basic group, and a conductive particulate material. Patent number." W O 01 / 18895 hwemors: H. Gyoten, O. Sakai, K. Hatoh, J. Niikura, H. Ohara, K. Nishida Publication date: 15 March 2001

Higher-temperature polymer electrolyte membrane fuel cells Applicant: Danish Power Systems, Denmark A method of preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a relatively high-temperature polymer electrolyte membrane (PEM) fuel cell. Blend polymer electrolyte membranes based on polybenzimidazole, and various thermoplastic polymers for high-temperature PEM fuel cells have also been developed. Miscible blends are used for solution-casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes. With the thermally resistant polymer, for example, polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled (with an aciddoped solid electrolyte membrane) by hotpressing. The fuel cell can operate at temperatures up to at least 200°C with hydrogen-rich fuel containing high ratios of" carbon monoxide (such as 3 vol% carbon monoxide or more), compared with the carbon monoxide tolerance of 10-20 ppm level for more conventional Nation-based PEM fuel cells. Patent number." WO 01 / 18894 Invemors: N.J. Bjerrum, Q. Li, H.A Hjuler Publication date.. 15 March 2001

Polymer electrolyte fuel cell

Chlorine dioxide generator

Applicant: Matsushita Electric Industrial, Japan

Applicant." International Dioxide, USA A vacuum-operated electrolytic generator can be used to produce a chlorine dioxide solution or a mist of chlorine dioxide from a buffered aqueous alkali metal chlorite solution in one pass through an electrolytic cell. The cell contains a high-surface-area anode, a corrosionresistant highly conductive cathode, and a cation-exchange membrane between the anode and cathode. An 'eductor' is used on the anolyte effluent line to create a vaccum and draw the anolyte through the cell. Either 'motive' water or a motive inert gas (such as air) is used in the eductor. Preferably, an eductor is used in the

Generally, a polymer electrolyte (PEM) fuel cell has a membrane-electrode assembly (MEA) comprising a polymer electrolyte film and a pair of gas-diffusing electrodes sandwiching the film. A conductive separator is provided on the outer face of the MEA. Although the conductive separator is made of a carbonaceous material, use of a metallic base material has been studied from the viewpoint of reducing the manufacturing cost. Such a conductive separator of a metallic base material is required to have strong corrosion resistance against long-term exposure to high-

MembraneTechnologyNo.136

catholyte effluent line. An ascending anolyte effluent line with a non-corrosive check valve leads from the cell to the anode eductor. Sensors are used to monitor the composition of the anolyte effluent and/or the anolyte feed. The final product is a chlorine dioxide solution when water is used for the eduction. The final product is a mist consisting essentially of gaseous chlorine dioxide, an inert gas, and water vapour when an inert gas is used for the eduction. The mist is useful for application to crops, soils, produce such as vegetables, fruit and tobacco, fields, storage cellars and the like. Patent number: W O 01/18279 Inventors: B.D. Krafton, J.C. Smedle); D.C. Kucher Publication date: 15 March 2001

Polysulfide production Applicants: Asahi Glass, Japan; Kawasaki

Kasei Chemicals, Japan; and Nippon Paper Industries, Japan A method of producing a polysultide, by subjecting a solution containing a sulfide to electrolytic oxidation, has been developed. It makes use of an electrolytic bath equipped with anode chambers with anodes, cathode chambers with cathodes, and diaphragms partitioning the anode chamber and a cathode chamber. Specific conditions for the electrolysis reaction are set, depending on the position adopted in the direction of the stream of a solution in the electrolytic bath. The method can be used for producing polysulfide sulfur in a high concentration while inhibiting the dissolution of an electrode material of an anode, and the byproduction of thiosulfate ions. Patent number: WO 01/18278 Inventors: E. Endoh, Z Shimohira, T. Andoh, J. Tanaka, K. Watanabe Publication date: I5 March 2001

Fuel-cell polymer membrane Applicant: DaimlerChrysler AG, Germany This invention relates to an ion-conductive polymer membrane for a fuel cell. The polymer membrane is configured from a polymer-forming hydrocarbon material. The membrane also has a metal-containing gel which has been hydrolysed and/or condensed from a metal alkoxide starting material, and which is deposited in the polymer and/or chemically bonded to the polymer. The proportion of metal alkoxide by weight, in relation to the membrane, lies between 25% and 1%. Patent plumber."WO 01/20700 Inventors: H. Biegert, P. Britz, G. Torh, P.. Urban Publication date: 22 March 200 l

Electro-deionization of water Applicant/Inventor: L. Mir (USA) An electro-deionization apparatus that can be used to purify water has been developed. It includes a cathode, an anode, and multiple alternating cation and anion permeable

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