Sulfur dioxide capture by deep eutectic solvents: Proposing purely predictive absorption models

Abstract

Sulfur dioxide (SO2) is one of the hazardous gases during coal or hydrogen sulfide combustion in petrochemical and coal-related industries. Unfortunately, SO2 is released into the atmosphere in most SO2-involved industries. The high concentration of SO2 in the atmosphere leads to acid rain, which leads to various damage and destruction of the environment. Therefore, preventing SO2 emissions into the atmosphere is vital. Considering environmental guidelines, Deep Eutectic Solvents (DESs), as the recent category of green solvents because of their eco-friendly characteristics are interesting. Considering the huge number of introduced DESs and also the costly and time-consuming process for experimental measurement of SO2 absorption by DESs, it is vital to have predictive thermodynamic models for predicting SO2 solubilities in DESs. In this study, for the first time in open literature, two general, accurate, and predictive models of atomic and group contributions were developed for SO2 absorption by various nature DESs based on a comprehensive data bank over wide ranges of temperatures and pressures. The gathered data bank includes 997 SO2 absorption data points for 65 various nature DESs. Both developed GC and AC models showed reliable and predictive performances by presenting the AARD% values of 10.3 and 11.7, respectively. © 2025 Elsevier B.V.