A Direct Carbon Fuel Cell (DCFC) is a
fuel cell
A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most batteries in re ...
that uses a carbon rich material as a fuel such as bio-mass or coal. The cell produces energy by combining carbon and oxygen, which releases carbon dioxide as a by-product. It is also called coal fuel cells (CFCs), carbon-air fuel cells (CAFCs), direct carbon/coal fuel cells (DCFCs), and DC-SOFC.
The total reaction of the cell is C + O
2 → CO
2.
The process in half cell notation:
* Anode: C + 2O
2− → CO
2 + 4e
−
* Cathode: O
2 + 4e
− → 2O
2−
Despite this release of carbon dioxide, the direct carbon fuel cell is more environmentally friendly than traditional carbon burning techniques. Due to its higher efficiency, it requires less carbon to produce the same amount of energy. Also, because pure carbon dioxide is emitted,
carbon capture techniques are much cheaper than for conventional power stations. Utilized carbon can be in the form of
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when dead ...
,
coke,
char, or a non-fossilized source of carbon.
At least four types of DCFC exist.
Solid oxide fuel cell based design
'' Anode reactions: ''
Direct electrochemical oxidation path:
: C + 2O
2− → CO
2 + 4e
−
: C + O
2− → CO+ 2e
−
Indirect electrochemical oxidation path: CO + O
2− → CO
2 + 2e
−
Boudouard reaction (indirect chemical reaction path): C + CO
2 → 2CO
'' Cathode reaction: '' O
2 + 4e
− → 2O
2−
Molten hydroxides fuel cell
William W. Jacques obtained US Patent 555,511 in this type of fuel cell in 1896. Prototypes have been demonstrated by the research group, SARA, Inc.
Molten carbonate fuel cell
William W. Jacques obtained a Canadian patent for the
molten carbonate fuel cell in 1897
It has been developed further at the
Lawrence Livermore Laboratory
Lawrence Livermore National Laboratory (LLNL) is a federal research facility in Livermore, California, United States. The lab was originally established as the University of California Radiation Laboratory, Livermore Branch in 1952 in response ...
.
Molten tin anode
This design utilizes molten tin and tin oxide as an inter stage reaction between oxidation of the carbon dissolving in the anode and reduction of oxygen at the solid oxide cathode.
[HyungKuk Ju, Sunghyun Uhm, Jin Won Kim, Rak-Hyun Song, Hokyung Choi, Si-Hyun Lee, Jaeyoung Lee, Enhanced anode interface for electrochemical oxidation of solid fuel in direct carbon fuel cells: The role of liquid Sn in mixed state, Journal of Power Sources 198 (2012) 36. doi:10.1016/j.jpowsour.2011.09.082]
See also
*
Glossary of fuel cell terms
The Glossary of fuel cell terms lists the definitions of many terms used within the fuel cell industry. The terms in this fuel cell glossary may be used by fuel cell industry associations, in education material and fuel cell codes and standards to ...
External links
CSIRO EnergyERTL, School of Environmental Science and Engineering, Gwangju Institute of Science and TechnologyCSIRO Advanced carbon powerDirect Carbon Fuel Cells an ultra low emission technology for power generation
*[http://www.sciencedirect.com/science/article/pii/S0378775311018532 DCFC Paper, Enhanced anode interface for electrochemical oxidation of solid fuel in direct carbon fuel cells: The role of liquid Sn in mixed state]
Science and Technology Review
References
{{Fuel cells
Fuel cells