Polymer fuel systems

Compatibility and Corrosion. Gas turbine fuels must be compatible with the elastomeric materials and metals used in fuel systems. Elastomers are used for O-rings, seals, and hoses as well as pump parts and tank coatings. Polymers tend to swell and to improve their sealing abiUty when in contact with aromatics, but degree of swell is a function of both elastomer-type and aromatic molecular weight. Rubbers can also be attacked by peroxides that form in fuels that are not properly inhibited (see Elastomers, synthetic Rubber, natural). 

D. Wilkinson, A. Steck, "General Progress in the Research of Solid Polymer Fuel Cell Technology at Ballard," Proceedings of the Second International Symposium on New Materials for Fuel Cell and Modern Battery Systems, Montreal, Quebec, Canada, July 6-10, 1997. 

K. Prater, "The Renaissance of the Solid Polymer Fuel Cell," Ballard Power Systems, Inc., Journal of Power Sources, p. 29, 1990. 

One of the major uses of activated carbon is in the recovery of solvents from industrial process effluents. Dry cleaning, paints, adhesives, polymer manufacturing, and printing are some examples. Since, as a result of the highly volatile character of many solvents, they cannot be emitted directly into the atmosphere. Typical solvents recovered by active carbon are acetone, benzene, ethanol, ethyl ether, pentane, methylene chloride, tetrahydrofuran, toluene, xylene, chlorinated hydrocarbons, and other aromatic compounds [78], Besides, automotive emissions make a large contribution to urban and global air pollution. Some VOCs and other air contaminants are emitted by automobiles through the exhaust system and also by the fuel system, and activated carbons are used to control these emissions [77,78],... 

Jensen, J., Li, Q., He, R., Xiao, G., Gao, J-A., Bjerrum, N. (2004). High temperature polymer fuel cells and their interplay with fuel processing systems. In "Hydrogen Power - Theoretical and Engineering Solutions, Proc. Hypothesis V, Porto Conte 2003" (Marini, M., Spazzafumo, G., eds.), pp. 675-683. Servizi Grafici... 

Major polymer applications automotive (fuel lines and connectors, fuel pump components, fuel tanks, filters, injection rails, air inlet, manifolds, gears, wheel covers), gears for business machines, liners for flexible fuel hoses, automotive fuel system components, industrial molded parts, film fibers... 

DaimlerChrysler s newest fuel cell is in the Mercedes-Benz b-class car. The fuel cell is a sandwich design with the polymer PEM cell between two gas permeable electrodes of graphite paper. Hydrogen is introduced to one side of the fuel cell while the other side is exposed to the air. Like the GM Hy-Wire platform, the fuel cells, fuel tank and fuel systems are under the floor. The compressor is in the front of the car to reduce the noise. There are four hydrogen sensors on the fuel cell stack, on each of the hydrogen tanks, another at the electric motor and another inside the cabin. 

R.F. Buswell, J. V. Clause, R. Cohen, C. Louie, and D.S. Watkins, Hydrocarbon fueled solid polymer fuel cell electric power generation system, Ballard U.S. Patent 5,360,679, 1994. 

Wul, G., Xu, J., and Miles, J., Polymer drag reduction in large diameter coal log pipeline. Proceedings of the International Technical Conference on Coal Utilization and Fuel Systems, 23, 889-900 (1998). 

The most common application of vegetable oil-modified polyamides is in the surface coatings and paints industry. The dimer acids of tall and soybean oils and amines are used to modify the flow behaviour of paints. This thixotropic flow prevents setting and sagging, enables easy application and improves surface appearance. Vegetable oil-based nylons are used as engineering polymers in the automotive and transport industry for fuel lines. Products are also used for the extruded and moulded components of fuel systems such as filler necks, gas tanks, reservoir modules, filters, fuel rails and vapour recovery systems. Nylon 11 is also used in power coatings to coat metals that must withstand abrasion, impact and corrosion. 

As is the case with fuel cells, depolarized cathodes have been considered for years but have not yet found wide commercial use in the chlor-alkali indusby. Reports of work in the 1970s and 1980s [117,118] described the use of solid-polymer electrolyte systems. Microporous electrodes are necessary for electrical continuity in these cells, and the cathode reaction takes place in the interior of the gas-diffiision electrode. Operating deficiencies include the gradual penetration of gas channels by caustic solution and the possibility of bulk flow of catholyte into the gas side of the electrodes. Section 17.2.2.2 describes more recent work that addresses these deficiencies. The first conunercial applications are beginning to appear. 

Joo and co-workers [22] have discussed a new type of composite membrane, consisting of functionalised carbon nanotubes (CNT) and sulfonated polyarylene sulfone (sPAS) for direct methanol fuel cell applications. The CNT modified with sulfonic acid or platinum-rubidium (PtRu) nanoparticles were dispersed within the sPAS matrix by a solution casting method to give SOs-CNT-sPAS or PtRu-CNT-sPAS composite membranes, respectively. Characterisation of the composite membranes revealed that the functionalised CNT were homogeneously distributed within the sPAS matrix and the composite membranes contained smaller ion clusters than the neat sPAS. The composite membranes exhibited enhanced mechanical properties in terms of tensile strength, strain and toughness, which leads to improvements in ion conductivity and methanol permeability compared with the neat sPAS membrane, which demonstrates that the improved properties of the composite membranes induce an increase in power density. The strategy for CNT-sulfonated composite membranes in this work can potentially be extended to other CNT-polymer composite systems. 

Ledjeff-Hey, K, Formanski, V, KaUc, T, Roes, J. Compact hydrogen production systems for solid polymer fuel cells. J. Power Sources 1998 71 199-207. 

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