Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Spectroscopic Identifications and Phase Equilibria of THF + 3-OH THF + CH4 Clathrate Hydrates

삼성분계 THF + 3-OH THF + CH4 크러스레이트 하이드레이트의 상평형 거동 해석 및 분광학적 분석

  • Kim, Heejoong (School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST)) ;
  • Ahn, Yun-Ho (Department of Chemical and Biomolecular Engineering (BK21+ program), Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Moon, Seokyoon (School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST)) ;
  • Hong, Sujin (School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST)) ;
  • Park, Youngjune (School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST))
  • 김희중 (광주과학기술원 지구환경공학부) ;
  • 안윤호 (한국과학기술원 생명화학공학과) ;
  • 문석윤 (광주과학기술원 지구환경공학부) ;
  • 홍수진 (광주과학기술원 지구환경공학부) ;
  • 박영준 (광주과학기술원 지구환경공학부)
  • Received : 2017.01.11
  • Accepted : 2017.02.13
  • Published : 2017.06.01
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Abstract

In this study, the inclusion phenomena of tetrahydrofuran + 3-hydroxytetrahydrofuran + $CH_4$ clathrate hydrates were explored via thermodynamic and spectroscopic approaches. The phase equilibria of the double hydrates - THF + $CH_4$ and 3-OH THF + $CH_4$ clathrate hydrates - were determined by pressure-temperature trace during hydrate formation and dissociation, and the result revealed that the equilibrium pressures were shifted to lower pressure region compared to pure $CH_4$ hydrate. The powder X-ray diffraction patterns revealed that the double hydrates of THF + 3-OH THF formed structure II type clathrate hydrates with $CH_4$. The dispersive Raman spectra of the double clathrate hydrates also exhibited that $CH_4$ can be trapped in both $5^{12}6^4$ and $5^{12}$ cages whereas THF and 3-OH THF were encaged in $5^{12}6^4$ cage.

본 연구에서는 THF + 3-OH THF + $CH_4$ + $H_2O$ 시스템에서의 크러스레이트 하이드레이트의 형성 과정과 이에 따른 상 거동을 열역학 및 분광학적 방법을 통해 분석하였다. 정적 반응기에서의 온도 변화에 따라 THF와 3-OH THF를 포함하는 유기 분자들의 큰 동공 내 점유에 의해 크러스레이트 하이드레이트가 형성 및 해리되는 현상을 압력 변화를 관찰함으로써 확인하였다. 또한, 이들 유기 분자의 상대 조성에 따라 크러스레이트 하이드레이트가 안정적으로 존재할 수 있는 상평형 영역이 순수 메탄 하이드레이트 대비 보다 낮은 압력 및 높은 온도 조건으로 이동될 수 있음을 확인하였다. 엑스선 회절 분광 분석을 통해 이들 조성에서의 크러스레이트 하이드레이트는 구조-II를 형성 하는 것을 확인하였으며, 라만 분광 분석을 통해 구조-II의 큰 동공과 작은 동공에 각각 메탄이 점유되어 있음을 또한 확인하였다.

Keywords

References

  1. Sloan, E. D. and Koh, C. A., "Clathrate Hydrates of Natural Gases," CRC press., 3rd ed. (2008).
  2. Kim, D. and Lee, H., "Phase Behavior of Gas Hydrates in Nanoporous Materials: Review," Korean J. Chem. Eng., 33(7), 1977-1988(2016). https://doi.org/10.1007/s11814-016-0064-z
  3. Veluswamy, H. P., Prasad, P. S. R. and Linga, P., "Mechanism of Methane Hydrate Formation in the Presence of Hollow Silica," Korean J. Chem. Eng., 33(7), 2050-2062(2016). https://doi.org/10.1007/s11814-016-0039-0
  4. Thomas, S. and Dawe, R. A., "Review of Ways to Transport Natural Gas Energy from Countries Which do Not Need the Gas for Domestic Use," Energy, 28, 1461-1477(2003). https://doi.org/10.1016/S0360-5442(03)00124-5
  5. Lee, Y. J., Kawamura, T., Yamamoto, Y. and Yoon, J. H., "Phase Equilibrium Studies of Tetrahydrofuran $(THF)\;+\;CH_4,\;THF\;+\;CO_2,\;CH_4\;+\;CO_2,\;and\;THF\;+\;CO_2\;+\;CH_4$ Hydrates," J. Chem. Eng. Data., 57, 3543-3548(2012). https://doi.org/10.1021/je300850q
  6. Sloan, E. D., "Fundamental Principles and Applications of Natural Gas Hydrates," Nature, 426, 353-359(2003). https://doi.org/10.1038/nature02135
  7. Sloan, E. D., Koh, C. A., Sum, A., Ballard, A. L., Creek, J., Eaton, M., Lachance, J., McMullen, N., Palermo, T., Shoup, G. and Talley, L., "Natural Gas Hydrates in Flow Assurance," Gulf Professional Publishing: Houston, TX, 87-97(2011).
  8. Ahn, Y. H., Kang, H., Koh, D. Y., Park, Y. and Lee, H., "Gas Hydrate Inhibition by 3-hydroxytetrahydrofuran: Spectroscopic Identifications and Hydrate Phase Equilibria," Fluid Phase Equilibr., 413, 65-70(2016). https://doi.org/10.1016/j.fluid.2015.12.005
  9. Kim, D., Ahn, Y. H. and Lee, H., "Phase Equilibria of $CO_2$ and $CH_4$ Hydrates in Intergranular Meso/Macro Pores of MIL-53 Metal Organic Framework," J Chem Eng Data, 60, 2178-2185(2015). https://doi.org/10.1021/acs.jced.5b00322
  10. Nixdorf, J. and Oellrich, L. R., "Experimental Determination of Hydrate Equilibrium Conditions for Pure Gases, Binary and Ternary Mixtures and Natural Gases," Fluid Phase Equilibr., 139, 325- 333(1997). https://doi.org/10.1016/S0378-3812(97)00141-6
  11. de Deugd, R. M., Jager, M. D. and Arons, J. D., "Mixed hydrates of Methane and Water-soluble Hydrocarbons Modeling of Empirical Results," Aiche J., 47, 693-704(2001). https://doi.org/10.1002/aic.690470316
  12. Rodriguezcarvajal, J., "Recent Advances in Magnetic-Structure Determination by Neutron Powder Diffraction," Physica B, 192, 55-69(1993). https://doi.org/10.1016/0921-4526(93)90108-I