SET Proceedings 2978-4387 Caravel Press 10.65582/set.2008.323 2008.323 Phase Equilibrium Conditions of Gas Hydrates for Natural Gas Solid Transportation and Storage KimNam-Jin jnkim@cheju.ac.kr ParkSung-Seek pss5153@cheju.ac.kr SeoHyang-Min shoo5029@cheju.ac.kr LeeYoon-Joon leeyj@cheju.ac.kr ChunWon-Gee wgchun@cheju.ac.kr College of Engineering, Cheju National University, Jeju, Korea 24082008 7 1 978-1-995850-08-5 2280 2287 24 August 2008 © 2008 Copyright WSSET 2008

Natural gas hydrates are ice-like solid substances, which are composed of water and natural gas, mainly methane. They have three kinds of crystal structures of five polyhedra formed by hydrogen-bonded water molecules, and are stable at high pressures and low temperatures. They contain large amounts of organic carbon and widely occur in deep oceans and permafrost regions. Therefore, they are expected as a potential energy resource in the future. Especially, 1m3 natural gas hydrate contains up to 172Nm³ of methane gas, depending on the pressure and temperature of production. Such large volumes make natural gas hydrates can be used to store and transport natural gas. In this study, three-phase equilibrium conditions for forming natural gas hydrate were numerically obtained in pure water. The results show that the predictions match the previous experimental values very well. And, help gases such that ethane, propane, i-butane, and n-butane reduce the hydrate formation pressure at the same temperature.

 Gas hydrate Natural gas Transportation Storage Phase equilibrium 24 to 27 August 2008 7th International Conference on Sustainable Energy Technologies SET2008 7 Seoul, Korea Chang, D. G., Kim, N. J., Lee, J. Y., and Kim, C. B., 2000, "Simulation of two phase flow in porous media after dissociation of methane hydrate," Proceeding of the KSME 2000 Fall Annual Meeting, pp. 241-246. Englezos, P., Kalogerakis, N., Dholabhai, P. D., and Bishnoi, P. R., 1987, "Kinetics of formation of mathane and ethane gas hydrate," Chemical Engineering Science, Vol. 42, No. 11, pp. 2647-2658. Gudmundsson, J. S., Andersson, V., and Levik, O. I., 1997, "Gas storage and transport using hydrates," Offshore Mediterranean Conference. Hammerschmidt, E. G., 1934, "Form ation of gas hydrates in natural gas transmission Lines," Int. Eng. Chem., Vol. 26, pp. 851-855. Kim, N. J., Lee, J. Y., Seo, T. B., and Kim, C. B., 2000, "Dissolution Characterist ics of Liquid CO2 Injected at the Intermediate Depth of the Ocean," KSME Int. J. Vol. 14, No. 11 pp. 1276-1285. Kvenvolden, K, A., 1988, "Methane hydrate-a major reservoir of carbon in the shallow geosphere?," Chem. Geol., Vol. 71, pp. 41-51. Kuhs, W. F., Chazallon, B., Radaelli, G., and Pauer, F, 1997, "Cage occupancy and compressibility of deuterated N2-hydrate by neutron diffraction," J. Incl. Phenom. Vol. 29, pp. 65-77. Okuda, Y., 1996, "Exploration research on gas hydrates in Japan," 5th Petroleum exploration and development symposium, pp. 62-98. Sloan, E. D., 1998, Clathrate hydrates of natural gases, Marcel Dekker, inc., New York, pp. 1-318. H. Kanda, 2006, Economics study on natural gas transportation with natural gas hydrate pellets, 23rd world gas conference, Amsterdam. Parrish, W. R. and Prausnitz, J. M., 1972, Dissociation Pressure of Gas Hydrates Formed by Gas Mixtures, Ind. Eng. Chem. Process Des. Dev., Vol. 11, pp. 26-34.