Vapor-Liquid Equilibrium Data for Binary Systems CO2 + Acetone, Butanone, 2-Pentanone, and 3-Pentanone at 253.15 K: Experimental Measurements and Correlations

Ketone solvents have been considered as potential absorbents for the coal-based syngas purification process. However, their vapor-liquid equilibrium (VLE) data with CO2 at low temperatures are insufficient. Therefore, in this study, acetone, butanone, 2-pentanone, and 3-pentanone were used as the absorbents, and their VLE data with CO2 were measured via a static method at 253.15 K. Subsequently, the Soave-Redlich-Kwong (SRK) and Peng-Robinson (PR) equations of state combined with the van der Waals (vdW) mixing rule and the Mathias-Klotz-Prausnitz (MKP) mixing rule were used to correlate the obtained experimental data, respectively. The correlation effects of different models were compared through the absolute average relative deviations between the experimental and calculated values of the molar fraction of CO2 in the vapor phase and system pressure. The results show that the average absolute relative deviations between the experimental and the calculated values for all models were less than 3.2%, which indicates the calculated values have a good correlation with the experimental values. Among them, the MKP mixing rule has better correlation effects of the CO2 + ketone systems than the vdW mixing rule. In addition, acetone has the best absorption capacity for CO2, followed by butanone, 2-pentanone, and 3-pentanone at the same experimental temperature and pressure. Overall, this study provides important basic thermodynamic data to design and develop cleaner and more sustainable syngas purification processes.