Evaluating Crystallization Risks in Liquefied-Natural-Gas (LNG) Production
- Luis F. Ayala (Pennsylvania State University) | Juan Emilio Fernandez (Pennsylvania State University)
- Document ID
- Society of Petroleum Engineers
- SPE Projects, Facilities & Construction
- Publication Date
- June 2009
- Document Type
- Journal Paper
- 27 - 31
- 2009. Society of Petroleum Engineers
- 4.1.1 Process Simulation, 4.6.2 Liquified Natural Gas (LNG), 5.2.1 Phase Behavior and PVT Measurements, 5.3.2 Multiphase Flow, 4.3.3 Aspaltenes, 4.1.4 Gas Processing, 7.4.3 Market analysis /supply and demand forecasting/pricing, 4.3.4 Scale, 1.8 Formation Damage, 4.2 Pipelines, Flowlines and Risers, 4.6 Natural Gas, 5.2.2 Fluid Modeling, Equations of State, 5.5 Reservoir Simulation
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- 450 since 2007
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Liquefied natural gas (LNG) is anticipated to dominate world energy trade and fill the gap between production and energy demands in a few years, especially in the US. LNG is the liquefied version of dry natural gases at ultralow temperatures (approximately -160ºC or -260ºF at atmospheric pressure), which aims at minimizing storage volume requirements needed for overseas transportation. Within this context, it is clear that technology must continue to be developed to optimize the thermodynamic processes involved in the compression, liquefaction, and revaporization of LNG and associated operational challenges. One key challenge during the production of LNG is the presence of trace amounts of heavy components in the gas feed composition is known to induce the precipitation of a solid phase during the cooling process, which presents the risk of equipment plugging and associated hazards. However, there are very few general thermodynamic tools available for the prediction of solid-liquid equilibrium for very low-temperature conditions (< 200ºF). In this study, available thermodynamic predictive tools are evaluated for the determination of LNG crystallization conditions. Previously presented crystallization prediction models are examined, and potential pitfalls identified. The results from this study are expected to provide a better understanding of the thermodynamics of LNG processes and provide a framework for subsequent work in the analysis of LNG refrigeration and liquefaction processes--typically considered the key elements of any LNG project.
Imported natural gas is expected to play a dominant role in meeting the projected rise of natural gas consumption during the coming decade in many industrialized countries. Traditional pipeline transportation is not a viable method for transoceanic delivery of natural gas supplies and thus, LNG becomes the method of choice for their marketing. The world market for LNG is anticipated to become extremely competitive in a few years, with the US not the only nation set on increasing LNG imports. To close the gap between domestic production and demand, dependence on LNG imports plays a greater factor on a worldwide scale, which requires greater infrastructure for LNG capacity, including expansion of existing terminals and the construction of new facilities. Within this context, it is clear that technology must continue to be developed to optimize the thermodynamic processes involved in the compression, liquefaction, and revaporization of LNG and associated operational challenges. Proper combination of good engineering design, operation, and maintenance is what allows handling and producing LNG safely (West and Chiu 2005; Alderman 1972).
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Ahmed, T. 2007. Equations of State and PVT Analysis, Chap. 6.Houston, Texas: Gulf Publishing Company.
AIChE. 2007. Design Institute for Physical Properties (DIPPR®), http://www.aiche.org/TechnicalSocieties/DIPPR/index.aspx.
Alderman, J.A. 2005. Introduction to LNG safety.Process Safety Progress 24 (3):144-151.DOI:10.1002/prs.10085.
Carter, K. and Luks, K.D. 2006. Extending a classical EOScorrelation to represent solid-fluid phase equilibria. Fluid PhaseEquilibria 243(1-2): 151-155.DOI:10.1016/j.fluid.2006.02.021.
de Hemptinne, J.-C. 2005. Benzene crystallization risks in theLIQUEFIN liquefied natural gas process. Process Safety Progress24 (3): 203-212. DOI:10.1002/prs.10084.
Eggeman, T. and Chafin, S. 2005. Beware the pitfalls of CO2 freezingprediction. Chemical Engineering Progress 101 (3):39-44.
Firoozabadi, A. 1999. Thermodynamics of Hydrocarbon Reservoirs, Chap.5. New York: McGraw-Hill.
Green, D.W. and Perry, R.H. 1997. Perry's Chemical Engineers'Handbook, seventh edition. New York: McGraw-Hill.
Green, K.A., Tiffin, D.L., Luks, K.D., and Kohn, J.P. 1979. Solubility ofHydrocarbons in LNG, NGL. Hydrocarbon Processing 58 (5):251-253.
Holder, G.D., Enick, R.M., and Mohamed, R.S. 1996. Solids formation inhydrocarbon systems. Fluid Phase Equilibria 117 (1-2):126-137. DOI:10.1016/0378-3812(95)02945-1.
Luks, K.D. and Kohn, J.P. 1981. Avoid freeze-up in LNG/LPG work.Hydrocarbon Processing 60 (4): 135-138.
Luks, K.D., Kohn, J.P., Liu, P.H., and Kulkarni, A.A. 1975. Solubility ofhydrocarbons in cryogenic NGL and LNG. Hydrocarbon Processing54 (5): 181-184.
Luks, K.D., Merrill, R.C., and Kohn, J.P. 1983. Partial miscibilitybehavior in cryogenic natural gas systems. Fluid Phase Equilibria14: 193-201. DOI:10.1016/0378-3812(83)80125-3.
Nghiem, L.X. and Kohse, B.F. 2006. Asphaltenes and Waxes. In PetroleumEngineering Handbook: General Engineering, Vol. 1, Chap. 9, ed. L. Lake.Richardson, Texas: SPE.
Orozco, C.E., Tiffin, D.L., Luks, K.D., and Kohn, J.P. 1977. Solids foulingin LNG systems. Hydrocarbon Processing 56 (11):325-328.
Peng, D-Y. and Robinson D.B. 1976. A new two-constant equation ofstate. Ind. Eng. Chem. Fund. 15 (1): 59-64.DOI:10.1021/i160057a011.
Prausnitz, J.M., Lichtenthaler, R.N., and de Azevedo, E.G. 1999.Molecular Thermodynamics of Fluid-Phase Equilibria, third edition, Chap.11. Upper Saddle River, New Jersey: International Series in the Physical andChemical Engineering Sciences, Prentice Hall PTR.
Soave, G. 1972. Equilibrium constantsfrom a modified Redlich-Kwong equation of state. Chem. Eng. Science27 (6): 1197-1203. DOI:10.1016/0009-2509(72)80096-4.
Ungerer, P., Lachet, V., and Tavitian, B. 2006. Applications of molecularsimulation in oil and gas production and processing. Oil & GasScience Technology-Rev. IFP 61 (3): 387-403.DOI:10.2516/ogst:2006040a.
Vidal, J. 2003. Thermodynamics: Applications in Chemical Engineering andthe Petroleum Industry, Chap. 1, 8, and 10. Paris: Editions Technip.
West, H.H. and Chiu, C-H. 2005. LNG safety: An issue of increasingimportance. Process Safety Progress 24 (3): 142-143.DOI:10.1002/prs.10086.
Won, K.W. 1986. Thermodynamics for solidsolution-liquid-vapor equilibria: wax phase formation from heavy hydrocarbonmixtures. Fluid Phase Equilibria 30: 265-279.DOI:10.1016/0378-3812(86)80061-9.
ZareNezhad, B. and Eggeman, T. 2006. Application ofPeng-Robinson equation of state for CO2 freezing prediction of hydrocarbonmixtures at cryogenic conditions of gas plants. Cryogenics46 (12): 840-845. DOI:10.1016/j.cryogenics.2006.07.010.
Zhi, Y., Meiren, S., Jun, S., and Lee, H. 2001. A new quartic equationof state. Fluid Phase Equilibria 187-188 (15September): 275-298. DOI:10.1016/S0378-3812(01)00542-8.