Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
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An Experimental Guide to Predictable Fuel Cell Operations by Controlling External Gas Supply

외부 유입 가스 조절을 통한 연료전지 구동 성능 안정화

  • Jang, Hansaem (School of Earth Sciences and Environmental Engineering, Ertl Center for Electrochemistry and Catalysis, Gwangju Institute of Science and Technology (GIST)) ;
  • Park, Youngeun (School of Earth Sciences and Environmental Engineering, Ertl Center for Electrochemistry and Catalysis, Gwangju Institute of Science and Technology (GIST)) ;
  • Lee, Jaeyoung (School of Earth Sciences and Environmental Engineering, Ertl Center for Electrochemistry and Catalysis, Gwangju Institute of Science and Technology (GIST))
  • 장한샘 (광주과학기술원 지구.환경공학부, Ertl 탄소비움연구센터) ;
  • 박영은 (광주과학기술원 지구.환경공학부, Ertl 탄소비움연구센터) ;
  • 이재영 (광주과학기술원 지구.환경공학부, Ertl 탄소비움연구센터)
  • Received : 2018.08.22
  • Accepted : 2018.09.06
  • Published : 2018.10.10
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Abstract

Fuel cell is one of the promising electrochemical technologies enabling power production with various fuel sources such as hydrogen, hydrocarbon and even solid carbon. However, its long-term performance is often unstable and unpredictable. In this work, we observed that gasification-driven hydrocarbons were the culprit of unpredictability. Therefore, we controlled the presence of hydrocarbons with the help of external gas supply, i.e. argon and carbon dioxide, and suggested the optimal amount of carbon dioxide required for predictable fuel cell operations. Our optimization strategy was based upon the following observations; carbon dioxide can work as both an inert gas and a fuel precursor, depending on its amount present in the reactor. When deficient, the carbon dioxide cannot fully promote the reverse Boudouard reaction that produces carbon monoxide fuel. When overly present, the carbon dioxide works as an inert gas that causes fuel loss. In addition, the excessive carbon monoxide may result in coking on the catalyst surface, leading to the decrease in the power performance.

연료전지는 높은 연료유연성을 갖고 있어, 탄소 및 탄화수소 등을 통해서도 전기를 생산할 수 있다. 하지만 이러한 연료원을 사용한 경우, 불안정한 장기 구동성능이 종종 관측된다. 본 연구에서는 반응기 내부에 존재하는 탄화수소가 장기 구동성능을 불안정하게 함을 밝힌다. 본 연구진은 비활성기체인 아르곤을 이용하여 산화극 반응기 내부의 가스화경로를 예측하고, 이를 통해 탄화수소의 영향을 억제하여 불안정한 장기 구동성능을 극복한다. 더 나아가, 산화극 반응기 내부에 이산화탄소를 공급하여 역부드아반응을 유도한다. 역부드아반응을 통해 탄소연료전지에서 연료로 사용될 수 있는 일산화탄소를 만들어낸다. 과도한 이산화탄소의 주입은 오히려 연료손실 등의 문제를 야기함을 확인한다. 따라서, 본 연구에서는 이산화탄소 공급량의 최적화가 중요함을 밝히고, 이를 통해 연료전지 구동 성능을 안정화한다.

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