Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Phase Behavior and Structural Analyses of the THF + H2 Binary Clathrate Hydrate

THF + H2 이성분계 크러스레이트 하이드레이트의 상거동 및 구조 분석

  • Cha, Jong-Ho (Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology) ;
  • Park, Youngjune (Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology) ;
  • Cha, Min-Jun (Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology) ;
  • Yeon, Sun-Hwa (Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology) ;
  • Lee, Huen (Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology)
  • 차종호 (한국과학기술원 생명화학공학과) ;
  • 박영준 (한국과학기술원 생명화학공학과) ;
  • 차민준 (한국과학기술원 생명화학공학과) ;
  • 연순화 (한국과학기술원 생명화학공학과) ;
  • 이흔 (한국과학기술원 생명화학공학과)
  • Received : 2008.12.04
  • Accepted : 2008.12.08
  • Published : 2008.12.31
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Abstract

In this study, we investigated that hydrate formation and phase behavior of the $THF+H_2$ binary clathrate hydrates. In order to confirm the binary clathrate hydrate formation we employed the Raman and NMR spectroscopies that are known to be quite powerful tools, particularly for examining the cage occupancy pattern of guest molecules. In addition, we traced the P-T profiles from clathrate hydrate formation and dissociation process, which made it possible for the resulting phase equilibrium boundary to be clearly established. In the binary clathrate hydrate matrix we further identified that the relatively large THF molecules can only occupy the large $5^{12}6^4$ cavities, while the small $H_2$ molecules are entrapped in the empty $5^{12}$ cavities in structure-II, making the hydrate to be stable above 273 K even at relatively low pressure condition. Considering that pure $H_2$ hydrate can be produced at the extreme pressures higher that 1,000 bar, we can conclude that the water-soluble second guest inclusion induces $H_2$ storage and transportation to be readily achievable under much milder conditions.

본 연구에서는 $THF+H_2$ 이성분계 하이드레이트 형성과 이에 따른 상거동을 살펴보았다. 이성분계 하이드레이트 형성을 확인하기 위하여 핵자기 공명 장비와 라만 분광 분석 장비를 이용하여 수소 분자의 하이드레이트 동공 점유 현상과 하이드레이트의 형성 및 해리 과정에서의 온도 압력 변화를 추적함으로써 상평형 영역을 확인하였다. 이에 따라 하이드레이트 형성 시 THF는 구조-II의 51264 동공에 $H_2$는 512 동공을 채우게 되며 비교적 상압과 상온의 조건에서 안정한 구조를 유지함을 알 수 있었다. 순수한 $H_2$ 하이드레이트는 1000 기압 이상의 매우 높은 압력 조건에서 형성된다는 사실을 고려한다면 THF는 훨씬 온화한 조건에서 쉽게 $H_2$ 저장을 유도할 수 있다는 사실을 알 수 있다.

Keywords

Acknowledgement

Supported by : 한국학술진흥재단

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