Thermodynamic Modeling of CO2-Rich Natural Gas Fluid Systems

  • José Luiz de MedeirosEmail author
  • Ofélia de Queiroz Fernandes Araújo


This chapter presents a survey on equation of state (EOS) for high-pressure natural gas (NG), pure CO2, and CO2-rich NG systems. The cubic EOS’s—PR-EOS, RK-EOS, SRK-EOS—are discussed in detail, with formulas for residual properties used in NG engineering. The text also discusses EOS’s of higher complexity for pure CO2 and CO2-rich NG: Span–Wagner EOS (SW-EOS), cubic-plus-association EOS (CPA-EOS), and GERG-2004/2008-EOS. EOS performances and applicability are qualitatively discussed. Some EOS’s are quantitatively compared for high-pressure pure CO2—including the critical neighborhood—in terms of density, enthalpy, isobaric heat capacity, and sound speed. The performance of the most popular EOS for NG processing—PR-EOS—is evaluated for CO2-rich NG, by comparing its predictions with available experimental vapor–liquid equilibrium (VLE) data—bubble-point, dew-point, and critical pressures—for the binary CH4–CO2 in wide ranges of compositions and temperatures. The binary CH4–CO2 is interesting because the literature has a reasonable amount of VLE CH4–CO2 data, and it is a prototype system for representation of high-pressure dry CO2-rich NG. The PR-EOS is also demonstrated with CH4–CO2 systems for predicting VLE envelopes and three-dimensional color maps on plane P × T for density, enthalpy, isobaric heat capacity, sound speed, isothermal compressibility, and isobaric expansivity of single-phase fluid.


  1. Ahmed, T.: Equations of state and PVT analysis applications for improved reservoir modeling. Gulf Publishing Company, Houston, Texas (2007)Google Scholar
  2. Al-Sahhaf, T.A., et al.: Liquid + vapor equilibria in the N2 + CO2 + CH4 system. Department of Chemical and petroleum. Refining Engineering, Colorado School of Mines (1983)Google Scholar
  3. Ávila-Méndez, G.A., Justo-García, D.N., García-Sánchez, F., García-Flores, B.E.: Prediction of phase behavior for the system methane-carbon dioxide-hydrogen sulfide-water with the PR and PC-SAFT equations of state. Open Thermodyn. J. 5(Suppl 1–M6), 63–70 (2011)CrossRefGoogle Scholar
  4. Donnelly, H.G., Katz, D.L.: Phase equilibria in the carbon dioxide—methane system. Ind. Eng. Chem. 46, 511 (1954)CrossRefGoogle Scholar
  5. Folas, G.K., Gabrielsen, J., Michelsen, M.L., Stenby, E.H., Kontogeorgis, G.M.: Application of the cubic-plus-association (CPA) equation of state to cross-associating systems. Ind. Eng. Chem. Res. 44, 3823–3833 (2005)CrossRefGoogle Scholar
  6. Genesis: Equation of state prediction of carbon dioxide properties. Project Kingsnorth Carbon Capture and Storage Project. CP-GNS-FAS-DRP-0001. (2011)
  7. Hlavinka, M.W., Hernandez, V.N., McCartney, D.: Proper interpretation of freezing and hydrate prediction results from process simulation. Bryan Research & Engineering, Inc. (2006)Google Scholar
  8. Hwang, S., et al.: Dew-point study in vapor-liquid region of the methane-carbon dioxide system. Department of Chemical Engineering, William Marsh Rice University, Houston (1976)CrossRefGoogle Scholar
  9. Im, U.K., Kurata, F.: Phase equilibrium of carbon dioxide and light paraffins in presence of solid carbon dioxide. J. Chem. Eng. Data 16(3), 295–299 (1971)CrossRefGoogle Scholar
  10. Kontogeorgis, G.M., Yakoumis, I.V., Meijer, H., Hendriks, E.M., Moorwood, T.: Multicomponent phase equilibrium calculations for water-methanol-alkane mixtures. Fluid Phase Equilib. 158–160, 201 (1999)CrossRefGoogle Scholar
  11. Kunz, O., Klimeck, R., Wagner, W., Jaeschke, M.: The GERG-2004 wide-range equation of state for natural gases and other mixtures. GERG Technical Monograph 15 (2007)Google Scholar
  12. Kunz, O., Wagner, W.: The GERG-2008 wide-range equation of state for natural gases and other mixtures: an expansion of GERG-2004. J. Chem. Eng. Data 57, 3032–3091 (2012)CrossRefGoogle Scholar
  13. Li, H.: Thermodynamic properties of CO2 mixtures and their applications in advanced power cycles with CO2 capture processes. Energy Processes Department of Chemical Engineering and Technology, Royal Institute of Technology, Stockholm, Sweden. TRITA-CHE Report 2008:58 (2008)Google Scholar
  14. Li, H., Yan, J.: Evaluating cubic equations of state for calculation of vapor-liquid equilibrium of CO2 and CO2-mixtures for CO2 capture and storage processes. Department of Chemical Engineering and Technology, Royal Institute of Technology (2009)CrossRefGoogle Scholar
  15. Moshfeghian, M.: How good are the detailed methods for sour gas density calculations? (2008b).
  16. Moshfeghian, M.: How good are the shortcut methods for sour gas density calculations? (2008a).
  17. Smith, J.P., Clancy, J.: Understanding AGA report no. 10, Speed of sound in natural gas and other related hydrocarbon gases. (2010)
  18. Span, R., Wagner, W.: A new equation of state for carbon dioxide covering the fluid region from the triple-point temperature to 1100 K at pressures up to 800 MPa. J. Phys. Chem. Ref. Data 25(6), 1509–1596 (1996)CrossRefGoogle Scholar
  19. Standing, M.B., Katz, D.L.: Density of natural gas gases. AIME Trans. 146, 140–149 (1942)CrossRefGoogle Scholar
  20. Webster, L.A., Kydnay, A.J.: Vapor–liquid equilibria for the methane-propan-carbon dioxide systems at 230 K and 270 K. Colorado School of Mines (2001)Google Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • José Luiz de Medeiros
    • 1
    Email author
  • Ofélia de Queiroz Fernandes Araújo
    • 1
  1. 1.Escola de QuímicaFederal University of Rio de Janeiro (UFRJ)Rio de JaneiroBrazil

Personalised recommendations