Highly efficient capture of odorous sulfur-based VOCs by ionic liquids

Ruinian Xu; Chengna Dai; Mingli Mu; Jun Cheng; Zhigang Lei; Bin Wu; Ning Liu; Biaohua Chen; Gangqiang Yu

doi:10.1016/j.jhazmat.2020.123507

Highly efficient capture of odorous sulfur-based VOCs by ionic liquids

J Hazard Mater. 2021 Jan 15:402:123507. doi: 10.1016/j.jhazmat.2020.123507. Epub 2020 Jul 17.

Authors

Ruinian Xu¹, Chengna Dai¹, Mingli Mu¹, Jun Cheng², Zhigang Lei², Bin Wu¹, Ning Liu¹, Biaohua Chen¹, Gangqiang Yu³

Affiliations

¹ College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, 100124, China.
² State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Box 266, Beijing, 100029, China.
³ College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, 100124, China. Electronic address: yugq@bjut.edu.cn.

PMID: 32763767
DOI: 10.1016/j.jhazmat.2020.123507

Abstract

This study proposes the capture of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) from waste gas using an ionic liquid (IL), namely, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf₂N]), and examines the process from a molecular level to the laboratory scale, which is then scaled up to the industrial level. The binding energy and weak interactions between DMS/DMDS and the anion/cation in [EMIM][Tf₂N] were investigated using quantum chemistry calculations to identify the capture mechanism at the molecular scale. A thermodynamic model (UNIFAC-Lei) was established by the vapor-liquid equilibrium data of the [EMIM][Tf₂N] + DMS/DMDS systems measured at the laboratory scale. The equilibrium and continuous absorption experiments were performed, and the results demonstrated that [EMIM][Tf₂N] exhibits a highly efficient capture performance at atmospheric conditions, particularly, absorption capacities (AC) for DMS and DMDS are 189.72 and 212.94 mg g^-1, respectively, and partial coefficients (PC) as more reasonable evaluation metrics for those are 0.509 × 10^-4 and 6.977 × 10^-4 mol kg^-1 Pa^-1, respectively, at the 100 % breakthrough. Finally, a mathematical model of the strict equilibrium stage was established for process simulations, and the absorption process was conceptually designed at the industrial scale, which could provide a decision-making basis for chemical engineers and designers.

Keywords: Dimethyl disulfide; Dimethyl sulfide; Ionic liquid; Molecular microstructural analysis; Process design.