(377u) Mechanism of SO2 absorption in Ionic Liquids

Authors: 
Zhang, X., Chinese Academy of Sciences
Zhang, S., Beijing Key Laboratory of Ionic Liquids Clean Process,CAS Key Labroratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences
Zeng, S., Chinese Academy of Sciences
Sulfur dioxide (SO2) has been resulting in a serious harm to environment and human health. On the other hand, SO2 also is an important source for synthesizing chemicals. Recently, ionic liquids (ILs) have been regarded as one of the most promising alternative solvents for capturing SO2 due to their special physicochemical properties, such as negligible vapor pressure and designable character. For example, it was found that N-butylpyridinium thiocyanate ([C4Py][SCN]) can absorb 0.841 gSO2/g IL at 293 K and 0.10 MPa1.

In this work, the mechanism of SO2 absorption in different kinds of ILs were systemically studied by molecular simulations. The microscopic structure, interaction energy and dynamic properties of the mixtures of ILs and SO2 were investigated. The results of the radial distribution functions and spatial distribution functions show that SO2 are mainly distributed above and below the center carbon plane of the cations, while the anions mainly exhibit strong affinity toward the most acidic hydrogen atoms of the cations. Anion has the closest affinity with SO2 than cation, which in charge of offering interaction sites to attract SO2. However, the cations also are crucial for SO2 absorption, which mainly provide space for accommodating SO2.

Acknowledgment

This work was supported by the National Natural Scientific Fund of China (51674234).

Reference

  1. J. Zeng, H. S. Gao, X. C. Zhang, H. F. Dong, X. P. Zhang, S. J. Zhang, Chem. Eng. J, 2014, 251, 248-256.