Experimental and theoretical study of CO2 solubility in N-methyl-2-pyrrolidone (NMP)

In this study, some new experimental data on the solubility of CO2 in N-methyl-2-pyrrolidone (NMP) is reported at different temperatures of 293 K, 313 K and 333 K and different pressures 0.5–1.1 MPa. The solubility of CO2 was evaluated by pressure decay method in a batch stirred absorption cell. The solubility data was also envisaged by using the thermodynamic modeling of the problem with 1-parameter and 2-parameter versions of Peng–Robinson equation of state (PR-EOS). Using the experimental data, the values of the binary interaction parameters (kij and lij) were optimized. The mean deviation between the measured solubility data and the predicted values by the thermodynamic model was calculated to be less than 3.5%. The results from both versions of PR-EOS are significantly similar. Therefore, it can be concluded that the application of 1-parameter model for NMP–CO2 system is simpler approach with sufficient accuracy to represent the vapor–liquid equilibria.