Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Study on the Separation of N2/SF6 Mixture Gas Using Polyimide Hollow Fiber Membrane

폴리이미드 중공사 막을 이용한 N2/SF6 혼합기체 분리에 관한 연구

  • 김대훈 (한국에너지기술연구원) ;
  • 김광림 (중국 연변과학기술대학교 화학공학과) ;
  • 조항대 (한국에너지기술연구원) ;
  • 박종수 (한국에너지기술연구원) ;
  • 이형근 (한국에너지기술연구원)
  • Received : 2010.04.20
  • Accepted : 2010.08.16
  • Published : 2010.10.31
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Abstract

In this research polyimide, Matrimid 5218, hollow fiber membrane was used to recover sulfur hexafluoride($SF_6$) which is one of the six greenhouse gases from $N_2/SF_6$ mixture gas. Fibers were spun from using dry-wet phase inversion method. The module was manufactured by fabricating fibers after surface coating with silicone elastomer. The scanning electron microscopy(SEM) studies showed that the produced fibers typically had an asymmetric structure; a dense top layer supported by a sponge-like substructure. The developed module had a permeance of 0.78-1.36 GPU for $N_2$ with $N_2/SF_6$ selectivity of 2.44-5.08 at various pressure and temperature. For recovery of $SF_6$, a membrane module and 10 vol.% $SF_6$ from $N_2/SF_6$ mixture gas was used. The effects of various operating condition such as pressure, temperature, and retentate side flow rate were tested. When pressure and temperature were increased and retentate flow rate was decreased, the $SF_6$ purity in recovered gas was increased up to 37.5 vol.% with decreasing recovery ratio. When retentate flow rate was increased pressure and temperature was decreased, the $SF_6$ recovery ratio in retentate side was increased up to 89% with decreasing the $SF_6$ purity in retentate side.

본 연구에서는 고분자 막을 이용하여 6대 온실가스 중 가장 높은 지구온난화지수를 갖는 육불화황(sulfur hexafluoride, $SF_6$)의 회수에 관한 연구를 실시하였다. 막 소재로 이미드 계열의 Matrimid 5218 소재를 건/습식 상전이 법을 이용하여 중공사 형태로 제조하고, 표면 실리콘 코팅 후 모듈을 제조하였다. 제조된 중공사 막은 전자주사현미경 관찰을 통하여 외부 표면에 치밀한 선택층과 망상구조의 하부로 이루어진 비대칭 구조를 확인하였다. 막의 기체투과 특성 확인을 위하여 온도와 압력 변화에 따른 $N_2$, $SF_6$ 단일 기체투과를 실시하였으며, 운전 조건에 따라서 0.78~1.36 GPU의 $N_2$ 투과도와 2.44-5.08의 $N_2/SF_6$ 선택도를 나타냈었다. 제조된 모듈의 혼합기체 분리거동 관찰을 위하여 10 vol.% $SF_6$ 농도를 갖는 $N_2/SF_6$ 혼합기체를 이용하여 온도, 압력, retentate 유량을 달리하여 실시하였으며, 실험을 통하여 압력과 온도 증가 및 retentate 유량 감소에 따라서 회수된 가스 중에 $SF_6$의 농도는 증가되어 최고 37.5 vol.%를 나타낸 반면 회수율은 감소되는 경향을 나타내었으며, 동일한 온도와 압력에서 retentate 유량 증가에 따라서 $SF_6$ 농도는 감소되는 반면 회수율이 증가하여 최고 89%의 회수율을 나타내었다.

Keywords

References

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