Experimental Measurement of Methane and Ethane Mole Fractions during Gas Hydrate Formation

Document Type: Research Article


Ahwaz Petroleum Faculty, Petroleum University of Technology (PUT), P.O. Box 6314661118 Ahwaz, I.R. IRAN


The super-saturation condition has to be provided to form gas hydrates. Consequently, the prediction of the guest molecule fraction in the aqueous phase is crucial in the study of the gas hydrate kinetics. In the present work, several experiments were carried out in a semi-batch reactor in order to determine the mole fraction of methane and ethane during gas hydrates formation (growth stage). The temperature ranged from 274.15 to 284.15 K. The experiment pressure ranges were 3100 to 7765 kPa and 950 to 2635 kPa for methane and ethane, respectively. The mole fraction is proportional to pressure while it is not affected by temperature to a great extent. Furthermore, the amount of guest dissolved in the liquid water was observed in the aqueous phase which was fairly constant during hydrates formation.


Main Subjects

[1] Sloan Jr, E.D., Koh, C., “Clathrate Hydrates of Natural Gases”, CRC Press, (2007).

[4] Vysniauskas A., Bishnoi P., A Kinetic Study of Methane Hydrate Formation. Chemical Engineering Science, 38(7): 1061-1072 (1983).

[5] Englezos P., Kalogerakis N., Dholabhai P., Bishnoi P., Kinetics of Formation of Methane and Ethane Gas Hydrates, Chemical Engineering Science, 42(11): 2647-2658 (1987).

[6] Englezos, P., Kalogerakis, N., Dholabhai, P.D., Bishnoi, P.R., Kinetics of Gas Hydrate Formation From Mixtures of Methane and Ethane, Chemical Engineering Science, 42(11): 2659-2666 (1987).

[7] Skovborg P., Rasmussen P., A mass Transport Limited Model for the Growth of Methane and Ethane Gas Hydrates, Chemical Engineering Science, 49(8): 1131-1143 (1994).

[8] Hashemi, S., Macchi, A., Servio, P., Gas hydrate Growth Model in a Semi Batch Stirred Tank Reactor. Industrial & Engineering Chemistry Research, 46(18): 5907-5912 (2007).

[9] Bergeron S., Servio P., Reaction Rate Constant of Propane Hydrate Formation, Fluid Phase Equilibria, 265(1): 30-36 (2008).

[10] Mohebbi V., Naderifar A., Behbahani R., Moshfeghian, M., Investigation of Kinetics of Methane Hydrate Formation During Isobaric and Isochoric Processes in an Agitated Reactor, Chemical Engineering Science, 76: 58-65 (2012).

[11] Sarshar M., Fathikalajahi J., Esmaeilzadeh F., Kinetic of Hydrate Formation of Propane and Its Mixture with Methane in a Circulating Flow Reactor, Fluid Phase Equilibria, 298(1): 38-47 (2010).

[12] Varaminian F., Abbasi nia Z., Modeling of Methane Hydrate Decomposition by Using Chemical Affinity, Iranian Journal Chemistry and Chemical Engineering (IJCCE), 29: 125-131 (2010).

[13] Yang S., Cho S., Lee H., Lee C., Measurement and Prediction of Phase Equilibria for Water+ Methane in Hydrate Forming Conditions, Fluid Phase Equilibria, 185(1): 53-63 (2001).

[14] Servio P., Englezos P., Measurement of Dissolved Methane in Water in Equilibrium with Its Hydrate, Journal of Chemical & Engineering Data, 47(1): 87-90 (2002).

[15] Seo Y., Lee H., Ryu B.J., Hydration Number and Two‐Phase Equilibria of CH4 Hydrate in the Deep Ocean Sediments, Geophysical Research Letters, 29(8): 85-81-85-84 (2002).

[16] Kim Y., Ryu S., Yang S., Lee C., Liquid Water-Hydrate Equilibrium Measurements and Unified Predictions of Hydrate-Containing Phase Equilibria for Methane, Ethane, Propane, and Their Mixtures, Industrial & Engineering Chemistry Research, 42(11): 2409-2414 (2003).

[17] Lang F., Servio P., Solubility Measurements for the CH4 + C2H6 + H2O System under Hydrate-Liquid-Vapour Equilibrium, Journal of Natural Gas Science and Engineering, 26: 130-134 (2015).

[19] Najafi M., Mohebbi V., Solubility Measurement of Carbon Dioxide in Water in the Presence of Gas Hydrate, Journal of Natural Gas Science and Engineering, 21: 738-745 (2014).

[20] Green D., Perry R., “Perry's Chemical Engineers' Handbook”, 8th Ed. McGraw-Hill Education, (2007).

[21] Mohebbi V., Naderifar A., Behbahani R., Moshfeghian M., Determination of Henry’s Law Constant of Light Hydrocarbon Gases at Low Temperatures, The Journal of Chemical Thermodynamics, 51: 8-11 (2012).

[22] Mohammadi A.H., Richon D., Development of Predictive Techniques for Estimating Liquid Water-Hydrate Equilibrium of Water-Hydrocarbon System, Journal of Thermodynamics, 2009: 1-12 (2009).

[23] Soave G., Equilibrium Constants From A Modified Redlich-Kwong Equation of State, Chemical Engineering Science, 27(6): 1197-1203 (1972).

[24] Someya S., Bando S., Chen B., Song Y., Nishio M., Measurement of CO2 Solubility in Pure Water and the Pressure Effect on it in the Presence of Clathrate Hydrate, Int. J. Heat Mass Transfer, 48(12): 2503-2507 (2005).

[25] Hashemi S., Macchi A., Bergeron S., Servio P., Prediction of Methane and Carbon Dioxide Solubility in Water in the Presence of Hydrate, Fluid Phase Equilibria, 246(1): 131-136 (2006).

[26] Bergeron S., Macchi A., Servio P., Theoretical Temperature Dependency of Gas Hydrate Former Solubility under Hydrate-Liquid Water Equilibrium. The Journal of Chemical Thermodynamics, 39(5): 737-741 (2007).

[27] Herri J.-M., Gruy F., Pic J.-S., Cournil M., Cingotti B., Sinquin A., Interest of in Situ Turbidimetry for the Characterization of Methane Hydrate Crystallization: Application to the Study of Kinetic Inhibitors, Chemical Engineering Science, 54(12): 1849-1858 (1999).

[28] Ribeiro C.P., Lage P.L., Modelling of Hydrate Formation Kinetics: State-of-the-Art and Future Directions, Chemical Engineering Science, 63(8): 2007-2034 (2008).

[29] Clarke M.A., Bishnoi P., Determination of the Intrinsic Kinetics of CO2 Gas Hydrate Formation Using in Situ Particle Size Analysis, Chemical Engineering Science, 60(3): 695-709 (2005).

[30] Naseh M., Mohebbi V., Behbahani R., Investigation of Ethane Hydrate Formation during Isobaric and Isothermal Conditions, Journal of Chemical & Engineering Data, 59: 3710-3716 (2014). doi:10.1021/je500588v

[31] Shagapov V.S., Zapivakhina M., Numerical Modeling of Gas Hydrates Decomposition in Gas Injection Into a Porous Medium, Theor. Found. Chem. Eng., 46(3): 248-257 (2012).