Direct carbon fuel cell

A Direct Carbon Fuel Cell (DCFC) is a fuel cell that uses a carbon rich material as a fuel such as bio-mass^[1] or coal.^[2] The cell produces energy by combining carbon and oxygen, which releases carbon dioxide as a by-product.^[3] It 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 + O₂ → CO₂. The process in half cell notation:

• Anode: C + 2 O²⁻ → CO₂ + 4 e⁻
• Cathode: O₂ + 4 e⁻ → 2 O²⁻

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, coke, char, or a non-fossilized source of carbon.^[4][5][6]

At least four types of DCFC exist:

• The first one is based on the Solid oxide fuel cell (SOFC) concept.^[7][8]

Overall reaction in the solid oxide electrolyte based DCFC

C + O₂ → CO₂.

Anode reaction

<Direct electrochemical oxidation path>

C + 2O²⁻ → CO₂ + 4e⁻

C + O²⁻ → CO+ 2e⁻

<Indirect electrochemical oxidation path>

CO + O²⁻ → CO₂ + 2e⁻

<Boudouard reaction:indirect chemical reaction path>

C + CO₂ → 2CO

Cathode reaction

O₂ + 4e⁻ → 2O²⁻

• The second one is molten hydroxides fuel cell. William W. Jacques obtained an US Patent 555,511 in this type of fuel cell in 1896. Prototypes have been demonstrated by the research group, SARA, Inc.^[9]
• The third one is based on the Molten Carbonate Fuel Cell (MCFC) concept. William W. Jacques obtained a Canadian patent in this type of fuel cell in 1897.^[10] It has been developed further at the Lawrence Livermore Laboratory.^[11]
• The fourth is a molten tin anode solid oxide fuel cell design, which 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.^[12][13]

See also

• Glossary of fuel cell terms
• ERTL, School of Environmental Science and Engineering, Gwangju Institute of Science and Technology
• Advanced carbon power^[14]

References

1. Munnings, C.; Kulkarni, A.; Giddey, S.; Badwal, S.P.S. (August 2014). "Biomass to power conversion in a direct carbon fuel cell". International Journal of Hydrogen Energy 39 (23): 12377–12385. doi:10.1016/j.ijhydene.2014.03.255.
2. Rady, Adam C.; Giddey, Sarbjit; Kulkarni, Aniruddha; Badwal, Sukhvinder P.S.; Bhattacharya, Sankar (October 2014). "Degradation Mechanism in a Direct Carbon Fuel Cell Operated with Demineralised Brown Coal". Electrochimica Acta 143: 278–290. doi:10.1016/j.electacta.2014.07.088.
3. Giddey, S; Badwal SPS; Kulkarni A; Munnings C (2012). "A comprehensive review of direct carbon fuel cell technology". Progress in energy and combustion science 38 (3): 360–399. doi:10.1016/j.pecs.2012.01.003.
4. Rady, Adam C.; Giddey, Sarbjit; Kulkarni, Aniruddha; Badwal, Sukhvinder P.S.; Bhattacharya, Sankar (October 2014). "Degradation Mechanism in a Direct Carbon Fuel Cell Operated with Demineralised Brown Coal". Electrochimica Acta 143: 278–290. doi:10.1016/j.electacta.2014.07.088.
5. Munnings, C.; Kulkarni, A.; Giddey, S.; Badwal, S.P.S. (August 2014). "Biomass to power conversion in a direct carbon fuel cell". International Journal of Hydrogen Energy 39 (23): 12377–12385. doi:10.1016/j.ijhydene.2014.03.255.
6. HyungKuk Ju, Jiyoung Eom, Jae Kwang Lee, Hokyung Choi, Tak-Hyoung Lim, Rak-Hyun Song, and Jaeyoung Lee, Durable power performance of a direct ash-free coal fuel cell, Electrochimica Acta 115 (2014) 511. doi:10.1016/j.electacta.2013.10.124
7. A Kulkarni, FT Ciacchi, S Giddey, C Munnings, SPS Badwal, JA Kimpton, D Fini (2012). "Mixed ionic electronic conducting perovskite anode for direct carbon fuel cells". International Journal of Hydrogen Energy 37 (24): 19092–19102. doi:10.1016/j.ijhydene.2012.09.141.
8. Tubular Solid Oxide Fuel Cell Technology, US Dept of Energy, retrieved 2012-01-01
9. Abundant Pollution-free Electricity Generation, retrieved 2012-01-01
10. http://patents.ic.gc.ca/cipo/cpd/en/patent/55129/summary.html
11. Turning carbon directly into electricity, 2001, retrieved 2012-01-01
12. http://web.archive.org/web/20090302040721/http://celltechpower.com:80/technology.htm. Archived from the original on March 2, 2009. Retrieved February 18, 2009. Missing or empty |title= (help)
13. 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
14. CSIRO. "Advanced carbon power". Retrieved 2015-02-12.

See also

• Direct Carbon Fuel Cells an ultra low emission technology for power generation
• Direct Carbon Fuel Cells, Alternative to a Hydrogen Economy?
• Direct Carbon Fuel Cell Workshop
• A closer look at Direct Carbon Fuel Cells: the ultimate biomass conversion technology?
• DCFC Paper, Enhanced anode interface for electrochemical oxidation of solid fuel in direct carbon fuel cells: The role of liquid Sn in mixed state

External links

• Science and Technology Review
• Direct Carbon Fuel Cell workshop