Alkaline fuel cells production

As the synergistic hydrogen production process using natural gas and nuclear heat is efficient and economic, and also the subsequent electro-chemical conversion of hydrogen into electricity in an alkaline fuel cell is efficient, electricity generation by combining these two processes have the following possibilities ... 

Electrode preparation methods significantly affect fuel cell performance. A variety of methods have been developed. For example, Bevers et al. [17] produced electrodes using a simple and less costly procedure, a modified rolling technique, formerly used in the production of electrodes for alkaline fuel cells and batteries. With these new electrodes, the same power output was obtained as that using commercial ones. 

This is an example of the use of alkaline fuel cells for production of industrially interesting compounds rather than for electricity production (Alcaide et al, 2004). 

In cases where high purity hydrogen is valued, dense metal membranes are an attractive option over polymeric membranes and porous membranes that exhibit much lower selectivities. Two examples where this is true are low-temperature fuel cells (e.g., proton exchange membrane fuel cells [PEMFCs] and alkaline fuel cells [AFCs]) and hydrogen-generating sites where the product hydrogen is to be compressed and stored for future use. 

Europe s first fuel cell bus, the Eureka, made its much-delayed debut in Brussels near the end of 1994. First announced in 1988, the Eureka was an articulated 59-foot 80-passenger device whose fuel cell and other components were housed in a two-wheeled trailer almost as long as the bus itself. A hybrid with an 87-kilowatt alkaline fuel cell made by the Belgian Elenco company plus NiCad batteries from French battery maker SAFT, it had electrical traction equipment from Italy s Ansaldo and a liquid-hydrogen fuel system contributed by Air Products of the Netherlands. The bus itself came from Van Hool. In all, the partners and the member governments spent about 8 million to get the bus on the road before its demise a few months later. Elenco was forced into bankruptcy in the spring of 1995 when the shareholders refused to come up with additional cash its assets... 

The reaction product of this reaction is water, which is formed at the cathode in acidic fuel cells. It can be formed at the anode, if an oxygen ion (or carbonate) conducting electrolyte is used, as in the case of high temperature fuel cells or in the case of the liquid alkaline fuel cell (see Section 8.1.4). The reaction product water has to be removed from the cell. 

The ORR catalysts are used in either acidic or basic electrolyte solutions, and when they are used in either acidic or alkaline fuel cells in the presence of high oxidizing oxygen, electrochemical stabilities of both the catalysts and their support materials are very important for their practiced applications. In the presence of O2, the potential of electrode coated with a catalyst (or the catalyst s potential) will be higher than 1.2 V vs RHE. This potential is higher than the oxidation potentials of almost all metal and carbon materials, or in other words, almost all metal and carbon materials are thermodynamically unstable in the sense of electrochemistry. However, due to the slow kinetics of the oxidation process, or the oxidation product is less soluble, the carbon and Pt-based materials can still be used as ORR catalysts for fuel cells even at acidic or basic environment and high temperatures such as 70-80 °C. 

Fuel cells must carry the costs of conditioning the two reactant gases as well as their own capital charges. Hydrogen requires transport to the anode side of the fuel cells. This is usually by rotary blower, but it also should be possible to operate membrane cells at some positive pressure and then to deliver the hydrogen without mechanical aid. The temperature and water content of the hydrogen must be considered in the overall heat and mass balance. Air and oxygen are candidates for use at the cathodes. The classical balance between cost and efficiency determines the choice. Wth alkaline fuel cells, the carbon dioxide in the air is of concern. It can consume the hydroxide value and contaminate the end product. It is possible to scrub the air to remove the CO2 before... 

Al-air fuel cells, Zn-Mn02 and Al-Mn02 cells, were assembled with anodes, cathodes and alkaline solid polymer electrolyte membranes. The electrochemical cells showed excellent cell power density and high electrode utilization. Therefore, these PVA-based solid polymer electrolyte membranes have great advantages in the applications for all-solid-state alkaline fuel cells. Some other potential applications include small electrochemical devices, such as supercapacitors and 3C electronic products. 

Much less attention has been given to ethanol oxidation in DEFC in alkaline medium. A problem with alkaline fuel cells is the carbonation of the solution due to CO2 production of the fuel oxidation and from air, which can cause solid... 

The local appearance of the reaction product is determined by the current-carrying ion. While for acidic fuel cells the reaction product shows up at the cathode (oxidant side), it is the anode (fuel side) for alkaline fuel cells. In case of C-containing fuels, e.g., methanol, a second reaction product containing the oxidized carbon appears at the... 

Jenseit W, Khalil A, Wendt H. Material properties and processing in the production of fuel cell components I. Hydrogen anodes from Raney nickel for lightweight alkaline fuel cells. J Appl Electrochem 1990 20(6) 893. 

Hydrogen produced from the decomposition of anunonia (600 °C) can be often used for feeding alkaline fuel cells, particularly suited for portable power applications. The performance of this reaction was developed by Ganley et al. [79] over a proper MSR configuration (Ru supported on aluminum-anodized alumina microchannels) resulting in a H2 production equivalent to 60W with an ammonia conversion of 99%, all in a volume of 0.35 cm, which exceeded the specifications for practical use laid out until that moment. 

A rechargeable Li-air battery requires that the ORR and OER be highly reversible. In the aqueous electrolyte, the ORR products (H2O2 and H2O as shown in Eqs. 1-3) are miscible (soluble) with the electrolyte solution, which makes the OER reversible. The aqueous electrolyte Li-air battery can share the same catalyst as those used in the alkaline fuel cells and metal-air batteries, which have been intensively... 

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