Molten carbonate Direct conversion

Ghezell-Ayagh et al. (1999) Development of a stack simulatioin model for control study on direct reforming molten carbonate fuel cell power plant, IEEE Trans. Energy Conversion, Vol. 14, No. 4. 

Note PAFC phosphoric acid fuel cell PEMFC proton exchange membrane fuel cell/polymer electrolyte membrane fuel cell MBFC microbiological fuel cell DMFC direct methanol conversion fuel cell AFC alkaline fuel cell MCFC molten carbonate fuel cell SOFC solid oxide fuel cell ZAFC zinc air fuel cell. 

Fuel cells (FCs) are electrochemical devices able to convert the chemical energy of reactions directly into electric energy [1]. The electrochemical conversion is possible in molten carbonate fuel cells (MCFCs) thanks to a ceramic matrix consisting of LiAl02 filled with a combination of molten alkali metal carbonates, which acts as an electrolyte and allows the transfer of carbonate ions from the cathode to the anode [2]. The electrochemical reactions occurring in MCFCs are as follows ... 

Direct Carbon Fuel Cells (DCFC). In direct carbon fuel cells, solid carbon (presumably a fuel derived from coal, pet-coke or biomass) is used directly in the anode, without an intermediate gasification step. Concepts with solid oxide, molten carbonate, and alkaline electrolytes are all under development. The thermodynamics of the reactions in a DCFC allow very high efficiency conversion. Therefore, if the technology can be developed into practical systems, it could ultimately have a significant impact on coal-based power generation. 

The polarization curve shown in Fig. 7 is of particular interest in the extension of direct carbon conversion to coal char conversion. The sample of coal was chemically cleaned by a process developed to manufacture carbon particulate fuel for gas turbines. (Ultra Clean Coal Pty. Ltd. Langley, 2004). Ash may be removed by a modified Bayer caustic digestion down to the level of 0.17%. At this level, the accumulation of ash necessary to reach 10%-volume criterion found by Weaver would require 1.5 yrs of operation at 0.1 A cm. The particulate coal (10 pm size) was charred in situ at 750°C in the presence of molten carbonate. The coal showed no tendency to agglomerate and flowed freely following pyrolysis as melt-wetted slurry. 

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