Experimental Study of the Phase Equilibria for $CO_2$ in Liquified Natural Gas Components at 77-219K

  • Yun, Sang-Kook (Department of Refrigeration and Air Conditioning Engineering, Korea Maritime University)
  • Published : 2003.06.01

Abstract

In order to prevent roll-over and a rapid boil-off of LNG in tanks, the phase equilibria of carbon dioxide in liquefied natural gas components as binary mixtures at cryogenic temperatures have been experimentally measured using Fourier transform infrared spectroscopy in conjunction with a specially designed variable pressure/temperature cryostat cell (pathlength 2 mm; pressures up to 30 bar). Solid carbon dioxide has been found to be comparatively soluble in liquid nitrogen (3.25$\times$${10}^{-6}$ mole fraction), liquid methane (1.04$\times$${10}^{-4}$ mole fraction), liquid ethane (3.1$\times$${10}^{-2}$ mole fraction) and liquid propane (6.11$\times$${10}^{-2}$ mole fraction) at their normal boiling temperatures. The solubilities of carbon dioxide in various cryogens, which increased with increasing temperature, are much lower than those obtained by others using gas chromatography. The differences are attributed to infrared spectroscopy selectively measuring dissolved solute in situ whereas gas chromatography measures microscopic particulate solid in addition to dissolved solute.

Keywords

References

  1. Heestand, J., Shipman, C. W. and Meader, J. W., 1983, A predictive model for rollover instratified LNG tanks, AIChE Journal, Vol. 29, No. 2, pp. 199-201
  2. Sugawara, Y., Kubota, A. and Muraki, S., 1984, Rollover test in LNG storage tank and simulation model, Advances in Cryogenic Engineering, Vol. 29, pp. 1-7
  3. Rest, A. J., Warren, R. and Murray, S. C., 1996, Assignment of the overtones and combination bands for liquid methane across the near infrared spectrum, Spectrochimica Acta, Part A, 52, pp. 1455-1463
  4. Fedorova, M. F., 1940, KOX, 14, p. 422
  5. Ishkin, I. and Burbo, 1939, KOX, 14, p. 1337
  6. Wojtaszek, Z. and Szczepaniec, E., 1969, Solubility of solid carbon dioxide in liquid nitrogen, Roczniki Chemii Ann. Soc. Chim. Polonarum, 43, p. 1289
  7. Cheung, H. and Zander, E. H., 1968, Chem, Eng. Progr, Sym. Ser., Vol. 64, No. 88, p.34
  8. Davis, J. A., Rodewald, N. and Kurata, F., 1962, AIChE J. Vol. 8, p. 1582
  9. Jensen, R. H. and Kurata, F., 1971, Heterogeneous phase behavior of solid carbon dioxide in light hydrocarbons at cryogenic temperatures, AIChE J., Vol. 17, No. 2, p. 357