Thermodynamic Models in the Duan Research Group

   
         
   
Files
Descriptions
Ref
d_CO2_H2O_NaCl.exe This program can accurately calculate the density, molar volume, apparent molar volume and apparent molar volume at infinite dilution of CO2-H2O-NaCl within the T-P-xCO2 range of 273.15-623.15 K, 0-1000bar and 0-0.05 xCO2. The applicable condition can be extended out of this range but its accuracies can not be guaranteed. Duan, Zhenhao; Hu, Jiawen; Li, Dedong; Mao, Shide(2008)Densities of the CO2-H2O and CO2-H2O-NaCl Systems Up to 647 K and 100 MPa. Energy & Fuels Vol: 22, Issue:3,1666-1674
EOS_CO2_H2O_2007.exe This program can be used to calculate the compressibility, molar volume and pressure of the CO2-H2O system. Hu, Jiawen; Duan, Zhenhao; Zhu, Chen; Chou, I-Ming(2007)PVTx properties of the CO2-H2O and CO2-H2O-NaCl systems below 647 K: Assessment of experimental data and thermodynamic models Chemical Geology Vol: 238, Issue:3-4,249-267

Fe_state_oxygen_fugacity_cal_viscosity

Viscosity_Calculation_Spreadsheet.xls

The first program can calculate Iron Oxidation State and Oxygen Fugacity in the melt systems according to the method of Moretti (2005)

The second spreadsheet can accurately predict the viscosity of various natural Fe-bearing melt over a wide range of temperatures (from 773 K to 2523 K), pressures (up to 130 kbar), H2O content (0-12.3 wt%), and compositions (ultramafic, mafic to silicic melts).

Moretti, R., 2005. Polymerisation, basicity, oxidation state and their role in ionic modelling of silicate melts. Annals of Geophysics. 48, 583-608

Xianzhe Duan (2013) A general model for predicting the viscosity of various natural iron-bearing silicate melt over a wide range of temperature, pressure and compositions. Submitted.

Fe_state_oxygen_fugacity_cal_solubility

H2O_CO2_Solubility_5.exe

The first program can calculate Iron Oxidation State and Oxygen Fugacity in the melt systems according to the method of Moretti (2005)

The second program predicts the solubility of H2O-CO2 in silicate melts over wide range of temperatures (from 933 K to 2003K), pressures (up to 30 kbar) and compositions (from ultramafic to silicic melts, from metaluminous to peraluminous, and from subalkaline to peralkaline).

Moretti, R., 2005. Polymerisation, basicity, oxidation state and their role in ionic modelling of silicate melts. Annals of Geophysics. 48, 583-608

Xianzhe Duan (2014) A general model for predicting the solubility behavior of CO2-H2O fluids in silicate melts over a wide range of pressure, temperature and compositions. Geochim. Cosmochim. Acta 125, 582-609..

Li&Duan2011.exe From 0 to 250 C, and from 1 to 1000 bar, the program calculates the vaporCliquidCsolid (calcite, gypsum, anhydrite and halite) equilibrium together with the chemical equilibrium of H-, Na+, Ca2+, CaHCO3+, Ca(OH)+, (OH)-, Cl-, HCO3-, HSO4-, SO42-, CO32-, CO2(aq), CaCO3(aq) and CaSO4(aq) in the aqueous liquid phase as a function of temperature, pressure and salt concentrations with accuracy close to the experimental results. Li, Jun; Duan, Zhenhao(2011)A thermodynamic model for the prediction of phase equilibria and speciation in the H2OCCO2CNaClCCaCO3CCaSO4 system from 0 to 250 C, 1 to 1000 bar with NaCl concentrations up to halite saturation Geochimica et Cosmochimica Acta Vol: 75, Issue:19,4351-4376
Duan&Li2008.exe This program calculates the coupled phase and aqueous species equilibrium in the H2OCCO2CNaClCCaCO3 system from 0 to 250 C, 1 to 1000 bar with NaCl concentrations up to saturation of halite. Duan, Zhenhao; Li, Dedong(2008)Coupled phase and aqueous species equilibrium of the H2OCCO2CNaClCCaCO3 system from 0 to 250 C, 1 to 1000 bar with NaCl concentrations up to saturation of halite. Geochimica et Cosmochimica Acta Vol: 72, Issue:20,5128-5145
GFluid.zip GFluid Worksheet is an Excel worksheetto calculate the thermodynamics properities and chemical equlibrium in the C-O-H fluid system, the most common fluid system in Earth's interior. It supports seven most important fluid species H2O, CO2, CH4, H2, CO , O2 and C2H6. Extract the package and see README.TXT Chi Zhang and Zhenhao Duan(2009) GFluid: An Excel spreadsheet for investigating C-O-H fluid composition in upper mantle Computers & Geosciences
Chi Zhang and Zhenhao Duan(2009) A model for C-O-H fluid in the Earth's mantle. Geochimica et Cosmochimica Acta accepted, doi: 10.1016/j.gca.2009.01.021
viscosity.exe
An accurate viscosity model over a wide range of temperature, pressure and concentration is developed for the LiCl-H2O(273-573 K, 1-400 bar and 0-16.7 m), NaCl-H2O(273-573 K, 1-500 bar and 0-6.0 m) and KCl-H2O(273-543 K, 1-500 bar and 0-4.5 m) systems with the experimental accuracy. Shide Mao & Zhenhao Duan (2008), The viscosity of aqueous alkali-chloride solutions up to high temperature, pressure and ionic strength, Journal of Chemical & Engineering Data.
density_model_on_net.exe
isochore_NaClH2O.exe
An accurate and simple density model over a wide range of temperature, pressure and concentration is developed for binary LiCl-H2O, NaCl-H2O, KCl-H2O, MgCl2-H2O, CaCl2-H2O, SrCl2-H2O and BaCl2-H2O systems within or about the experimental uncertainties. The infinite dilute apparent molar volume, density and isochores of the fluid inclusions can be calculated from this density model. Shide Mao & Zhenhao Duan (2008) The PVT properties of aqueous chloride fluids up to high temperatures and pressures. The Journal of Chemical Thermodynamics
EOS_C_H.exe This program is used to calculate volumetric properties and activity of the H2O-CH4 673K to 2573K up to 10 Gpa. Chi Zhang, Zhenhao Duan* and Zhigang Zhang (2006) Molecular simulation of the CH4 and CH4-H2O systems with ab initio potential surface up to 10GPa and 2573K. Geochimica Cosmochimica Acta
h2o_cacl2.exe
h2o_mgcl2.exe

These two programs are used to calculate volumetric properties and liquid-vapor phase euiqlibria of the H2O-CaCl2 and H2O-MgCl2 systems from 523K to 973K and from water satuartion pressure up to 1500bar.
Zhenhao Duan, John Weare and Nancy Moller (2006) A high temperature equation of state for the H2O-CaCl2 and H2O-MgCl2 systems. Geochimica Cosmochimica Acta
A thermodynamic model is presented to calculate N2 solubility in pure water (273-590 K and 1-600 bar) and aqueous NaCl solutions (273-400 K, 1-600 bar and 0-6 mol kg-1), gas phase composition of the H2O-N2-NaCl system (273-523 K and 1-300 bar), the N2 solubility in seawater, and liquid phase density of H2O-N2-NaCl system at phase equilibrium.
Shide Mao & Zhenhao Duan (2006) A thermodynamic model for calculating nitrogen solubility, gas phase composition and density of the H2O-N2-NaCl system. Submitted to Fluid Phase Equilibria.
EOS for the system of H2O, CO2 and CO2-H2O, which was proposed on the basis of MD simulation results (click here to download) and experimental data. This EOS is expected to show improved accuracy for the PVTx properties of CO2-H2O from 673.15 K up to 2573.15 K and 10.0 GPa. The prediction power of this EOS can be found here.
Zhenhao Duan & Zhigang Zhang (2006) Equation of state of the H2O, CO2, and H2O-CO2 systems up to 10 GPa and 2573.15 K: Molecular dynamics simulations with ab initio potential surface.Geochim. Cosmochim. Acta.
This model can calculate water content of gas phase for CH4-H2O-NaCl system; CH4 solubility in pure water and aqueous NaCl solutions ; CH4 solution heat(deltaH) and partial volume(VlCH4) in pure water and aqueous NaCl solutions;The liquid density for CH4-H2O-NaCl system at equilibria and CH4 solubility in seawater and brines. The T-P-m range is: 273-523 K, 1-2000 bar and 0-6 m.
Zhenhao Duan & Shide Mao (2006) A thermodynamic model for calculating methane solubility, density and gas phase composition of methane-bearing aqueous fluids from 273 to 523 K and from 1 to 2000 bar. Geochim. Cosmochim. Acta.
This program is to calculate ethane solubilities in water and aqueous NaCl solutions. T-P range for ethane-water system is: 273-444 K; 0-1000 bar. T-P-m range for ethane-water-NaCl system is: 273-348 K; 0-16 bar; 0-6.3 m.
Shide Mao, et al. (2005) An accurate model for calculating C2H6 solubility in water and aqueous NaCl solutions. Fluid Phase Equilibria, 238: 77-86
Programs for the prediction of CH4 and CO2 hydrate phase equilibrium and cage occupancy. All the relevant files (codes and binaries) are included in the .zip compressed file. Separate files can also be downloaded one by one. Instructions can be found in Readme.txt
Rui Sun and Zhenhao Duan (2005) Prediction of CH4 and CO2 hydrate phase equilibrium and cage occupancy from Ab Initio intermolecular potential. Geochim. Cosmochim. Acta, 69: 4411-4424.
Programs for the prediction of CH4 and CO2 hydrate phase equilibrium in aqueous NaCl solution, in seawater, and in brines containing Na+, K+, Ca2+, Mg2+, Cl-, and SO42-.
Zhenhao Duan and Rui Sun, A Model to Predict Phase Equilibrium of CH4 and CO2 Clathrate Hydrate in Aqueous Electrolyte Solutions, American Mineralogist.
Source code in PASCAL and descriptions can be found here. [Duan_Hu_Eos.rar]
Duan Zhenhao, Hu Jiawen, (2004) A new cubic equation of state and its applications to the modeling of vapor-liquid equilibria and volumetric properties of natural fluids. Geochim. Cosmochim. Acta, 68 (14): 2997-3009
This program calculates the solubility of CO2 in pure water and in aqueous NaCl solution. T-P-X range of this model: 273-533 K, 0-2000 bar, 0-4.5 m NaCl.

Zhenhao Duan and Rui Sun (2003) An improved model calculating CO2 solubility in pure water and aqueous NaCl solutions from 273 to 533 K and from 0 to 2000bar. Chem. Geol., 193: 253-271

Duan ZH, Sun R, Zhu C, et al. (2006) An improved model for the calculation of CO2 solubility in aqueous solutions containing Na+, K+, Ca2+, Mg2+, Cl-, and SO42-. Marine Chem., 98 (2-4): 131-139.

This program calculates molar volume and the composition of CH4-H2O system at phase equilibrium. T-P range of this model: 273-383 K, 0 -1000 bar.
Rui Sun and Zhenhao Duan (2003) A new equation of state and Fortran 77 program to calculate vapor-liquid phase equilibria of CH4-H2O system at low temperatures. Computers & Geosciences 29: 1291-1299
EOS for pure water, which was proposed on the basis of MD simulation results and experimental data. This EOS is expected to show improved accuracy for the volumetric properties of liquid water from 100.0 MPa and 273.15 K up to substantial ionization limit (about 20 GPa and 2000 K)
Zhigang Zhang and Zhenhao Duan. (2005) Isothermal-isobaric molecular dynamics simulations of the PVT properties of water over wide range of temperatures and pressures. Phys. Earth Planet Interiors, 149: 335-354