Experimental Investigation of Natural Gas Components During Gas Hydrate Formation in Presence or Absence of the L-Tyrosine as a Kinetic Inhibitor in a Flow Mini-loop Apparatus

Document Type: paper

Author

Chemical Engineering, Petroleum and Gas Department, Shiraz University of Technology, Shiraz, Iran

Abstract

Hydrates are crystalline compounds similar to ice, with guest molecules like methane and ethane trapped inside cavities or cages formed by the hydrogen bounded framework of water molecules. These solid compounds give rise to problems in the natural gas oil industry because they can plug pipelines and process equipments. Low dosage hydrate inhibitors are a recently developed hydrate control technology, which can be more cost-effective than traditional practices such as methanol and glycols.
The main objective of the present work is to experimentally investigate simple gas hydrate formation with or without the presence of kinetic inhibitors in a flow mini-loop apparatus.  For this purpose, a laboratory flow mini-loop apparatus was set up to measure the induction time and gas consumption rate during gas hydrate formation when a hydrate forming substance such as methane, ethane, propane, carbon dioxide and  iso- butane is contacted with water in the absence or presence of dissolved inhibitor at various concentration under suitable temperature and pressure conditions. In each experiment, a water blend saturated with pure gas is circulated up to a required pressure. Pressure is maintained at a constant value during experimental runs by means of the required gas make-up. The effect of pressure on gas consumption during hydrate formation is investigated with or without the presence of PVP (polyvinylpyrrolidone) and L-tyrosine as kinetic inhibitors at various concentrations. The experimental results show that increasing the pressure of the system, causes to increase the experimental gas consumption and decrease the induction time. Also, the extent of gas hydrate formation at a given time is clearly less in the presence of the inhibitors. Moreover, when comparing the gas consumption during the hydrate formation for simple gas hydrate formation in presence of PVP and L-tyrosine inhibitors, it is seen that the gas consumption in presence of L-tyrosine is lower than that of PVP for all experiments.

Keywords


[1] Davy, H. (1811). On a Combination of Oxymuriatic Gas and Oxygene Gas, Phil. Trans, R. Soc. London, Vol. 101, No. 1, PP. 155-162.

[2] Sloan, E.D. (2008). Clathrate Hydrates of Natural Gases. third ed., CRC Press, New York. 

[3] Tohidi, B., Danesh, A. and Todd, A.C. (1995). "Modelling single and mixed electrolyte solutions and its application to gas hydrates." Chem. Eng. Res. Design, 73, 464-472.

[4] Klug, P., Dahlmann, U. and Feustel, M. (2005). "Additives for inhibiting gas hydrate formation." United States Patent, 6,894,007.

[5] Lovell, A. C. and Pakulski, M. (2003). "Two low-dosage hydrate inhibitors." Journal of Petroleum Technology, 55, No. 4, 65 – 68.

[6] Bishnoi, P. and Dholabhai, P. D. (1993). "Solutions" Fluid Phase Equilibria, 83, 455-462.

[7] Hammerschmidt, E.G. (1934). "Formation of Gas Hydrates in Natural Gas Transmission Lines", Industrial Engineering Chemistry, Vol. 26, No. 8, PP. 851-855.

[8] Knox, W.G., Hess, M., Jones, G.E. and Smith, H.B. (1961). "The hydrate process." Chem. Eng. Prog., Vol 57(2), PP. 66-71.

[9] Vysniauskas, A. and Bishnoi, P. R. (1983). "A kinetic study of methane hydrate formation." Chemical Engineering Science, Vol. 38, PP.1061-1072.

[10] Barker, J.W. and Gomez, R.K. (1989). “Formation of hydrates during deepwater drilling operation.” Journal of Petroleum Technology, 41, 297.

[11] Stergaard, K. K., Tohidi, B., Danesh, A., and Todd, A. C. (2000). "Gas Hydrates and Offshore Drilling Predicting the Hydrate Free Zone." Annals of the New York Academy of Sciences, 912, 411-419.

[12] Javanmardi, J., Moshfeghian, M. and Peters, C. J. (2002). "Modeling the Gas Hydrate Formation Conditions in the Mixture of Acetone and Water." Iranian Journal of Science and Technology, Vol. 26, No. B2, 241-248.

[13] Javanmardi, J., Nasrifar, Kh., Najibi, S. H. and Moshfeghian, M. (2003). “Considering of Natural Gas Transfer in the form of Hydrate and Operational Conditions Investigation.” Research on Science and Engineering of Petroleum, 12(46)

[14] Javanmardi, J., Nasrifar, Kh., Najibi, S. H., and Moshfeghian, M.(2007). “Natural Gas Transportation, NGH or LNG.” World Review of Science, Technology and Sustainable Development, 4(2).258-267.

[15] Javanmardi, J., Moshfeghian, M. and Maddox, R. N. (2001). "An accurate model for Prediction of Gas Hydrate Formation Conditions in Mixture of Aqueous Electrolyte Solutions and Alcohol." Canadian Journal of Chemical Engineering, 79(3), 367-373 .

[16] Kashchiev, D. and Firoozabadi, A. (2002). "Nucleation of gas hydrates", Journal of Crystal Growth, 243, 476-489.

[17] Makogan, Y.F.(1997). Hydrates of Hydrocarbon, Penn Well Books.

[18] Kashchiev, D. and Firoozabadi, A. (2003)." Induction time in crystallization of gas hydrates", J. Crys. Growth, 250, 499-515.

[19] Englezos, P., Kalogerakis, N., Dholabhai, P.D. and Bishnoi, P.R. (1987). "Kinetics of gas hydrate formation from mixtures of methane and ethane." Chem. Eng. Sci., 42, 2659-2666.

[20] Skovborg, P. and Rasmussen, P.(1994)."A mass transport limited model for the growth of methane and ethane gas hydrates." Chem. Eng. Sci., 49, 1131-1143.

[21] Gaillard, C. Monfort, J. P. and Peytavy. J. L. (1999). "Investigation of methane hydrate formation in a re-circulating flow loop: modeling of the kinetics and tests of efficiency of chemical additives on hydrate inhibition." Oil and Gas Science and Technology-, Rev., Vol. 54, No.3, PP. 365-374.

[22] Bishnoi, P.R. and Natarajan, V. (1996). " Formation and decomposition of gas hydrates." Fluid Phase Equilibria, 117, 168-177.

[23] Jensen, L., Thomsen, K. and Solms, N.V. (2008). "Propane hydrate nucleation: Experimental investigation and correlation.” Chem. Eng. Sci., 63, 3069-3080.

[24] Talaghat, M.R., Esmaeilzadeh, F. and Fathikalajahi, J. (2009). "Experimental and theoretical investigation of simple gas hydrate formation with or without presence of kinetic inhibitors in a flow mini-loop apparatus." Fluid Phase Equilibria, 279, 28-40.

[25] Talaghat, M.R., Esmaeilzadeh, F. and Fathikalajahi, J. (2009). "Experimental and theoretical investigation of double gas hydrate formation with or without presence of kinetic inhibitors in a flow mini-loop apparatus." Chemical Engineering and Technology, 32(5), 805-819

[26] Talaghat, M.R. (2009). "Effect of various types of equations of state for prediction of simple gas hydrate formation with or without the presence of kinetic inhibitors in a flow mini-loop apparatus.” Fluid Phase Equilibria, 286, 33-43.

[27] Costello, C. A., Berluche, E., Oelfke, R. H. and Talley, L. D. (1999). "Methods for inhibiting hydrate formation using maleimide copolymers." US Patent 5 936 040.