Development and application of prediction model for CO2 solubility in ionic liquids

CO2 solubility in ionic liquids is an important parameter for CO2 capture and recovery by ionic liquids. A semi-empirical and semi-mechanism model was proposed for predicting CO2 solubility in ionic liquids. A predictive model was first constructed based on Krichevsky-Kasarnovsky equation. The Henry's constant using empirical Valentiner and infinite dilution partial molar volume using empirical polynomial were used to modify the model and extend its application. The experimental data of CO2 solubility in various ionic liquids and associated pressures and temperature ranges were divided into training and testing sets. The training set covered the corresponding operating conditions and nonlinear least square optimization algorithm was used to learn and correct the model parameters to improve prediction accuracy. Subsequently, the prediction performance of the model was evaluated using the testing set. Evaluation results show that this prediction model is successful in the prediction of CO2 solubility in various ionic liquids. The prediction results match the experimental data. In conclusion, this work provides a theoretical method for data analysis of CO2 solubility in ionic liquids. © 2019, Editorial Board of "Journal of Chemical Engineering of Chinese Universities". All right reserved.