Removal of Odorants by Selective Adsorption from Natural Gas for Protection of Steam Reforming Catalyst in Fuel Cell from Sulfur Poisoning

연료전지용 개질기 촉매의 피독방지를 위한 천연가스 중의 황성분 부취제의 선택적 흡착제거

  • 오상승 (인하대학교 생명화학공학부) ;
  • 김건중 (인하대학교 생명화학공학부)
  • Received : 2007.05.03
  • Accepted : 2007.06.26
  • Published : 2007.08.10

Abstract

The reforming catalyst and the electrodes in fuel cells can be poisoned by the organic sulfur compound which is added as an odorant for checking out the leakage of natural gas, and that makes a big problem of system degradation. In this study, various adsorbents, such as silica, ${\gamma}$-alumina, activated carbon, HZSM-5, Ultra-stable Y zeolite (USY), and beta zeolite (BEA), were utilized to remove tetra-hydrothiophene (THT) and tert-butylmercaptan (TBM), and to confirm the performance in the adsorption of those odorants by using a continuous adsorptive bed. The effects of Si/Al ratio of zeolites, adsorption temperature and the type of balance gas (methane or He) on the adsorption performance in the packed bed have been investigated. In addition, the competitive adsorption between TBM and THT on the adsorbents was also estimated. The result shows that H-type BEA zeolite exhibited the highest adsorption capacity for TBM and THT odorant, and the higher amount of THT was removed adsorptively on the same adsorbent than TBM. The physical and chemical adsorption of those compounds on acid sites of zeolite were confirmed by temperature programmed desorption (TPD) and infrared spectrum (IR) analyses.

천연가스의 누출을 감지하기 위해서 첨가되는 유기 황 화합물질인 부취제에 의해 연료전지 내의 스택 전극과 개질기 촉매들이 피독되어 시스템 성능저하의 큰 원인이 되고 있다. 본 연구에서는 실리카, 알루미나, 활성탄, HZSM-5, Ultra-stable Y 제올라이트(USY) 및 베타 제올라이트와 같은 흡착제들을 부취제 제거용 흡착제로 사용하여, tetra-hydrothiophene (THT)와 tert-butylmercaptan (TBM)에 대한 흡착 성능을 연속식 흡착시스템에서 얻은 흡착파과곡선을 비교하여 평가하였다. 제올 라이트의 Si/Al 비, 흡착온도 및 Balance Gas (메탄, 헬륨) 종류의 변화가 흡착성능에 미치는 영향을 조사하고, THT와 TBM의 경쟁적인 흡착특성을 비교하였다. 여러 흡착제 중에서 H형, beta-zeolite (BEA)가 부취제인 TBM과 THT에 대해서 가장 우수한 흡착능력을 나타내었으며, 동일한 흡착제 상에서는 THT가 TBM보다 많은 양으로 흡착제거되었다. Temperature Programmed Desorption (TPD) 및 Infrared 스팩트럼(IR) 분석결과 부취제 황화합물은 제올라이트 표면에서 물리흡착과 더불어 산점에 의한 화학흡착을 이루는 것을 확인하였다.

Keywords

References

  1. A. L. Dicks, J. Power source, 61, 113 (1996)
  2. J. Larmine and A. Dicks, Fuel Cell System Explained, 1st ed., 1, JOHN WIELY & SONS, Ltd., London (1996)
  3. T.-Y. Song, The report of characterization research on adsorbed odorants upon natural gas, Korean Gas Corporation, Seongnam (2002)
  4. R. H. Cunningham, M. Fowles, R.M. Ormerod, and J. Staniforth, The Report of Sulphur poisoning of the active materials used in SOFCs, DTI. Co. Ltd, Ohio (2004)
  5. C. Pereira, J.-M Bae, S. Ahmed, and M. Krumpelt, Proceedings of the 2000 Hydrogen Program review, California (2000)
  6. I. I. Novochinskii, C.-S. Song, X. Ma, X. Liu, L. Shore, J. Lampert, and R. J. Farrato, Energy & Fuels, 18, 576 (2004)
  7. P. J. de Wild, R. G. Nyqvist, F. A. de Bruijin, and E. R. Stobbe, The Proceedings of 1st European Hydrogen Energy Conference, Grenoble (2003)
  8. H. Wakita, Y. Tachibana, and M. Hosaka, Microporous and Mesoporous Materials, 46, 237 (2001) https://doi.org/10.1016/S1387-1811(01)00299-2
  9. J. Lampert, J. of Power Sources, 131, 27 (2004) https://doi.org/10.1016/j.jpowsour.2004.01.022
  10. L. Wang, K. Mutrata, and M. Inaba, Applied Catalysis A: General, 257, 43 (2004) https://doi.org/10.1016/S0926-860X(03)00590-8
  11. C. L. Garcia and J. A. Lercher, J. of Phy. Chem., 96, 2230 (1992)
  12. M. Suzuki, Adsorption Engineering, Kodansha Ltd., Tokyo, (1990)
  13. K. Sato and A. Maeda, JARI Research J., 25, 13 (2003)
  14. S. H. Lee, T. Y. Song, and Y. S. Baek, J. Korean Institute of Gas, 5, 36 (2000)
  15. Y.-W. Choi, J.-H. Kim, K.-H. Choi, and S.-S. Shin, J. Korean Society of Analytical Sciences, 7, 349 (1994)
  16. M. Sugioka, F. Sado, T. Kurosaka, and X. Wang, Catalysis Today 45, 327 (1998)