A systematic mathematical model to accurately predict SO2 absorption performance of binary mixture of alkanolamine and ionic liquid

Abstract

In the absorption of SO₂, it is very important for industrial applications to set up mathematical models to describe the changes in physical–chemical properties and the absorption dynamic processes. However, most of the research only pays attention to the molecular structure of absorbent. Few works have investigated the mathematical models in the absorption processes. To make up for the research gap in this area, a binary absorbent composed of 2-(dibutylamino)ethanol (DBEA) and 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([Emim][TfO]) were developed for SO₂ capture in the present work. A systematic mathematical model was proposed to accurately predict the viscosity and density of the absorption system with different absorbent compositions, SO₂ absorption capacities, and temperatures. Additionally, the absorption kinetics and thermodynamics were analyzed across varying absorbent compositions and SO₂-containing gas flows, enabling dynamic prediction of the absorption process. Furthermore, the correlation between desorption residuals and desorption temperature was investigated, along with an analysis of SO₂/CO₂ selectivity and the cyclic SO₂ absorption performance. This work provides a robust framework for rational screening and design of alkanolamine-IL hybrid solvents, bridging the gap between experimentally empirical solvent development and theoretical prediction.