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Correlation Between Surface Properties of Fuel and Performance of Direct Carbon Fuel Cell by Acid Treatment

석탄 산처리에 따른 연료의 표면 물성 변화와 직접탄소 이용 연료전지 성능 간의 상관관계 분석분석

  • Received : 2016.05.10
  • Accepted : 2016.08.24
  • Published : 2016.11.01

Abstract

Coal modified by acid treatment was investigated to analyze the correlation between the cell performance and electrochemical parameters in a direct carbon fuel cell (DCFC). The fuels were subjected to thermogravimetry analysis, gas adsorption test, and X-ray photoelectron spectroscopy to investigate the fuel properties and surface characteristics. After the treatment of raw coal, the thermal reactivity of the treated fuels increased, and the specific surface area decreased, though the mean pore diameters of three fuels were similar. The coal treated by $HNO_3$ showed the highest ratio of oxygen to carbon, and also an increase in the surface oxygen groups on the fuel surface. Through comparison between the fuel surface properties and electrochemical performance, it was confirmed that the surface oxygen groups have an influence on the improvement in the DCFC performance.

본 논문에서는 역청탄인 Glencore 탄을 염산과 질산수용액을 이용하여 산 처리하고 원탄과 산 처리 된 석탄의 물리, 화학적 비교분석과 직접탄소 이용 연료전지(Direct Carbon Fuel Cell, DCFC)의 성능 비교 분석을 수행하였다. 석탄의 물성들을 분석하기 위해 열중량 분석과 가스 흡착법, X선 광전자 분광법을 수행하였다. 열중량 분석을 통해 연료의 열적 반응성이 증가하였음을 알 수 있었고, 가스 흡착법 결과로 기공의 평균지름은 변화가 없었지만 표면적은 감소함을 알 수 있었다. X선 광전자 분광법에서는 $HNO_3$ 처리의 경우 가장 높은 산소/탄소 비율을 보였고, 이를 통해 다양한 표면 산소작용기가 증가한 것을 확인하였다. 연료의 표면 물성과 전기화학 성능을 비교한 결과, 표면의 산소 성분의 변화가 DCFC의 성능 향상에 가장 큰 영향을 미침을 알 수 있었다.

Keywords

References

  1. Ahn, S., Eom, S., Rhie, Y., Moon, C., Sung, Y., Choi G. and Kim, D., 2012, "A Study on the Effect of Coal Properties on the Electrochemical Reactions in the Direct Carbon Fuel Cell System," Trans. Korean Soc. Mech. Eng. B, Vol. 36, No. 10, pp. 1033-1041. https://doi.org/10.3795/KSME-B.2012.36.10.1033
  2. Giddey, S., Badwal, S. P. S., Kulkarni, A. and Munnings, C., 2012, "A Comprehensive Review of Direct Carbon Fuel Cell Technology," Progress in Energy and Combustion Science, Vol. 38, pp. 360-399. https://doi.org/10.1016/j.pecs.2012.01.003
  3. Cooper, J. F. and Selman, J. R., 2012, "Analysis of the Carbon Anode in Direct Carbon Conversion Fuel Cells," International Journal of Hydrogen Energy, Vol. 37, No. 24, pp. 19319-19328. https://doi.org/10.1016/j.ijhydene.2012.03.095
  4. Li, X., Zhu, Z., De Marco, R., Dicks, A., Bradley, J., Liu, S. and Lu, G., 2008, "Factors That Determine the Performance of Carbon Fuels in the Direct Carbon," Industrial & Engineering Chemistry Research, Vol. 47, No. 23, pp. 9670-9677 https://doi.org/10.1021/ie800891m
  5. Li, X., Zhu, Z., De Marco, R., Bradley, J. and Dicks, A., 2010, "Evaluation of Raw Coals as Fuels for Direct Carbon Fuel Cells," Journal of Power Source, Vol. 195, No. 13, pp. 4051-4058. https://doi.org/10.1016/j.jpowsour.2010.01.048
  6. Li, X., Zhu, Z., Chen, J., De Marco, R., Dicks, A., Bradley, J. and Lu, G., 2009, "Surface Modification of Carbon Fuels for Direct Carbon Fuel Cells," Journal of Power Source, Vol. 186, No. 1, pp. 1-9. https://doi.org/10.1016/j.jpowsour.2008.09.070
  7. Elleuch A., Halouani K. and Li Y., 2015, "Investigation of Chemical and Electrochemical Reactions Mechanisms in a Direct Carbon Fuel Cell using Olive Wood Charcoal as Sustainable Fuel," Journal of Power Source, Vol. 281, pp. 350-361. https://doi.org/10.1016/j.jpowsour.2015.01.171
  8. Ahn, S., Rhie, Y., Eom, S., Sung, Y., Moon, C., Kang, K., Choi, G. and Kim, D., 2012, "An Experimental Study on the Characteristics of Electrochemical Reactions of RDF/RPF in the Direct Carbon Fuel Cell," Transactions of the Korean Hydrogen and New Energy Society, Vol. 23, No. 5, pp. 513-520. https://doi.org/10.7316/KHNES.2012.23.5.513
  9. Rhie, Y., Eom, S., Ahn, S., Choi, G. and Kim, D., 2013, "A Study on Effect of Thermal Decomposition Products of Coal on Anodic Reactions in Direct Carbon Fuel Cell," Transactions of the Korean Hydrogen and New Energy Society, Vol. 24, No. 5, pp. 413-420. https://doi.org/10.7316/KHNES.2013.24.5.413
  10. Ahn, S., Eom, S., Rhie, Y., Sung, Y., Moon, C., Choi, G. and Kim, D., 2013, "Utilization of Wood Biomass Char in a Direct Carbon Fuel Cell (DCFC) System," Applied Energy, Vol. 105, pp. 207-216. https://doi.org/10.1016/j.apenergy.2013.01.023
  11. Fauth, D. J., Hoffman, J. S., Reasbeck, R. P. and Pennline, H. W., 2004, "CO2 Scrubbing with Novel Lithium Zirconate Sorbents," Preprints American Chemical Society Division Fuel Chemistry (SAUS), Vol. 49, pp. 310-311.
  12. Eom, S., Ahn, S., Rhie, Y., Kang, K., Sung, Y., Moon, C., Choi, G. and Kim, D., 2014, "Influence of Devolatilized Gases Composition from Raw Coal Fuel in the Lab Scale DCFC (Direct Carbon Fuel Cell) System," Energy, Vol. 74, pp. 734-740. https://doi.org/10.1016/j.energy.2014.07.039
  13. Lopez-Garzon, F. J., Domingo-Garcia, M., Perez-Mendoza, M., Alvarez, P. M. and Gomez-Serrano, V., 2003, "Textural and Chemical Surface Modifications Produced by Some Oxidation Treatments of a Glassy Carbon," Langmuir, Vol. 19, No. 7, pp. 2838-2844. https://doi.org/10.1021/la026848d
  14. Thommes, M., Kaneko, K., Neimark, A. V., Olivier, J. P., Rodriguez-Reinoso, F., Rouquerol, J. and Sing, K. S., 2015, "Physisorption of Gases, with Special Reference to the Evaluation of Surface Area and Pore Size Distribution (IUPAC Technical Report)," Pure and Applied Chemistry, Vol. 87, No. 9-10, pp. 1051-1069.
  15. Zhou, F., Liu, S., Pang, Y., Li, J. and Xin, H., 2015, "Effects of Coal Functional Groups on Adsorption Microheat of Coal Bed Methane," Energy & Fuels, Vol. 29, No. 3, pp. 1550-1557. https://doi.org/10.1021/ef502718s
  16. Figueiredo, J. L., Pereira, M. F. R., Freitas, M. M. A. and Orfao, J. J. M., 1999, "Modification of the Surface Chemistry of Activated Carbons," Carbon, Vol. 37, No. 9, pp. 1379-1389. https://doi.org/10.1016/S0008-6223(98)00333-9
  17. Karr, C., 2013, Analytical Methods for Coal and Coal Products, Vol. 2, Academic Press, pp. 256-258.
  18. Eom, S., Cho, J., Ahn, S., Sung, Y., Choi, G. and Kim, D., 2016, "Comparison of the Electrochemical Reaction Parameter of Graphite and Sub-bituminous Coal in a Direct Carbon Fuel Cell," Energy & Fuels, Vol. 30, No. 4, pp. 3502- 3508. https://doi.org/10.1021/acs.energyfuels.5b02904
  19. Hao, W., He, X. and Mi, Y., 2014, "Achieving High Performance in Intermediate Temperature Direct Carbon Fuel Cells with Renewable Carbon as a Fuel Source," Applied Energy, Vol. 135, pp. 174-181. https://doi.org/10.1016/j.apenergy.2014.08.055
  20. Chen, C. C., Maruyama, T., Hsieh, P. H. and Selman, J. R., 2012, "Wetting Behavior of Carbon in Molten Carbonate," Journal of The Electrochemical Society, Vol. 159, No. 10, pp. D597-D604. https://doi.org/10.1149/2.022210jes
  21. Tulloch, J., Allen, J., Wibberley, L. and Donne, S., 2014, "Influence of Selected Coal Contaminants on Graphitic Carbon Electro-oxidation for Application to the Direct Carbon Fuel Cell," Journal of Power Sources, Vol. 260, pp. 140-149. https://doi.org/10.1016/j.jpowsour.2014.03.026