On the Properties of CO2 and Flue Gas at the Piperazinium-Based Ionic Liquids Interface: A Molecular Dynamics Study

Abstract

CO2 capture using ionic liquids is among the most promising alternatives for flue gases treatment; in particular, piperazine-based fluids have attracted great attention both in industry and in academia. The reported results obtained in this work using molecular dynamics simulations allow analyzing the behavior of CO2 and a model flue gas at the interface of N-alkylpiperazinium-based ionic liquids. Density profiles across the boundary show changes in the orientation and ordering of involved ions at the interface, thus leading to changes in surface tension. Likewise, CO2 and ionic liquids systems show strong accumulation of CO2 molecules at the interface in short times, whereas crossing the interface and diffusing to the bulk ionic liquids is a slower process. For flue gas and ionic liquid systems, CO2 molecules accumulate at the interface and water molecules also tend to form a layer out of the interface, whereas the effect of the remaining flue gas components is not remarkable. The behavior of the studied...