Modeling of Carbon Dioxide Solubility in Pz-CO2-H2O System

In this research, a thermodynamic model based on the Pitzer and Virial equations was presented for modeling of carbon dioxide-water-Piperazine equilibrium system. The model was constructed based on electrolytes principles including mass balance, electroneutrality, chemical equilibrium and phase equilibria. In the model, activity coefficients of liquid species were determined using Pitzer equation whereas fugacity coefficients of gas species were calculated using Virial equation. The modeling equations of carbon dioxide-water-Piperazine system including a set of linear and nonlinear equations were solved simultaneously using Newton method. The simulation results were compared with other researcher's experimental data. The mean absolute error for 376 experimental data was obtained 7.18 percent. Also comparison of the model results with other thermodynamic model results showed that the model has high accuracy for prediction of carbon dioxide solubility than the other models.