The Molten Carbonate Fuel Cell

This type of fuel cell operates at a temperature of about 600 C, which is enough to enhance the rate of reaction at both electrodes and allow oxidation of most fuels, just 

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The PAFC is, however, suitable for stationary power generation, but faces several direct fuel cell competitors. One is the molten carbonate fuel cell (MCFC), which operates at "650°C and uses an electrolyte made from molten potassium and lithium carbonate salts. Fligh-teinperature operation is ideal for stationary applications because the waste heat can enable co-generation it also allows fossil fuels to be reformed directly within the cells, and this reduces system size and complexity. Systems providing up to 2 MW have been demonstrated. 

In order to describe the geometrical and structural properties of several anode electrodes of the molten carbonate fuel cell (MCFC), a fractal analysis has been applied. Four kinds of the anode electrodes, such as Ni, Ni-Cr (lOwt.%), Ni-NiaAl (7wt.%), Ni-Cr (5wt.%)-NijAl(5wt.%) were prepared [1,2] and their fractal dimensions were evaluated by nitrogen adsorption (fractal FHH equation) and mercury porosimetry. These methods of fractal analysis and the resulting values are discussed and compared with other characteristic methods and the performances as anode of MCFC. 

Just as the aqueous, alkaline fuel cell can be adopted to C02 separation and concentration, the molten carbonate fuel cell (MCFC) can function in this application as well. Recall that the MCFC cathode operates with the net reaction... 

Carbon dioxide supply, for the molten carbonate fuel cell, 72 220 Carbon dioxide ternary systems, phase behavior of, 24 4—5 Carbon diselenide, 22 75t Carbon disulfide, 4 822-842 23 567, 568, 621. See also CS2 in cellulose xanthation, 77 254 chemical reactions, 4 824—828 diffusion coefficient in air at 0° C, 7 70t economic aspects, 4 834-835 electrostatic properties of, 7 621t handling, shipment, and storage, 4 833-834... 

In the molten carbonate fuel cell, methane is used as the fuel. This cell runs at high temperatures and uses a molten mixture of lithium and potassium carbonates as electrolyte. In most such cells, the methane is reformed into hydrogen and carbon monoxide before reacting in the cell ... 

The molten carbonate fuel cells employ LijCOj-f CC (62.38 mol.%) electrolytes, porous Ni alloy, and lithiated nickel oxide as anodes and cathodes at an operating temperature of 723 K. The half-cell reactions of each side are, respectively... 

Fig. 2.1. Working principle of the Molten Carbonate Fuel Cell (MCFC) with direct internal reforming (DIR).

The electrolyte in this fuel cell is generally a combination of alkali carbonates, which are retained in a ceramic matrix of LiA102 [8], This fuel cell type works at 600°C-700°C, where the alkali carbonates form a highly conductive molten salt with carbonate ions providing ionic conduction. At the high operating temperatures in the molten carbonate fuel cell, a metallic nickel anode and a nickel oxide cathode are adequate to promote the reaction [9], Noble metals are not required. 

The most important fuel cells that are in use nowadays are the polymer electrolyte membrane fuel ceU (PEMFC), the molten carbonate fuel cell (MCFC), and the solid oxide fuel cell (SOFC). In a PEMFC, the electrolyte is a polymer membrane that conducts protons, in an MCFC the electrolyte is a carbonate melt in which oxygen is conducted in the form of carbonate ions, CO , and in an SOFC the electrolyte is a solid oxide that conducts oxygen ions, While a PEMFC can be operated at low temperatures of about 80 °C, an MCFC works at intermediate temperatures of about 650 °C, and an SOFC needs relatively high temperatures of 800-1000 °C (see next sections). 

Similar efforts in solid-state electrochemistry for SOFC development focus on the exploration of new perovskites not only for the ORR but also for the anodic oxidation of hydrocarbons [182]. In this area, the discovery that Cu-based anodes present a viable alternative to the classical Ni-YSZ cermet anodes is particularly noteworthy [166, 183, 184], owing to the significant enhancement of performance by avoiding coke deposition. Similar important advances have occurred in the molten carbonate fuel cell (MCFC) area [9]. 

Iwase, Y. Okada, H. Kuroe, S. Mitsuishima, S. Takeuchi, M. Enhancement and stabilization of the molten carbonate fuel cell performance by optimization of electrode pore distributions. Denki Kagaku 1994, 62 (2), 152-157. 

Legergren, C. Lundblad, A. Bergman, B. Synthesis and performance of LiCo02 cathodes for the molten carbonate fuel cell (MCFC). J. Electrochem. Soc. 1994, 141 (11), 2959-2966. 

Smith, D.S. Winnick, J. Cesium-containing electrolyte for the molten carbonate fuel cell. Electrochem. Solid State Lett. 1999, 2 (5), 207-209. 

In the molten carbonate fuel cell (MCFC) a mixture of potassium and lithium carbonate is used as an electrolyte. It is thus possible to reach a far higher temperature, about 650°C, than in the three types already mentioned. 

Finally we come to the fuel cell itself. We have already mentioned the original Grove fuel cell, and the alkaline and phosphoric acid fuel cells used in space technology. Three other types of cell are the molten carbonate fuel cell (with a molten Li2C03/Na2C03 electrolyte), the solid oxide fuel cell (containing a solid metal oxide electrolyte) and the... 

Molten carbonates have been receiving attention due to the development of the molten carbonate fuel cell that uses CO2 as a reactant. CO2 easily reacts with salts and other impurities to form highly corrosive products. 

Cassir M and Belhomme C (1999), Technological applications of molten salts the case of the molten carbonate fuel cell . Plasmas Ions, 2,3-15. 

Thermal management of the molten carbonate fuel cell plane. 

Bosio, B., Costamagna, P., Parodi, F., and Passalacqua, B. (1998) Industrial experience on the development of the molten carbonate fuel cell technology. 

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