Viscosity of 1-Alkyl-1-methylpyrrolidinium Bis(trifluoromethylsulfonyl)imide Ionic Liquids Saturated with Compressed CO ₂

Journal Article · Wed Apr 03 00:00:00 EDT 2019 · Journal of Chemical and Engineering Data

DOI:https://doi.org/10.1021/acs.jced.8b01237· OSTI ID:1567699

C. Morais, Ana Rita ^[1]; Shiflett, Mark B. ^[1]; Scurto, Aaron M. ^[1]; Baek, Donna L.  ^[2]; Fox, Robert V.  ^[2]; Alaras, Luis M. ^[1]

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1. Univ. of Arkansas, Fayetteville, AR (United States)
2. Idaho National Lab. (INL), Idaho Falls, ID (United States)

The viscosity of mixtures of pyrrolidinium-based ionic liquids saturated with compressed CO₂ was measured using a high-pressure viscometer at three different temperatures (298.15, 318.15 and 338.15 K). The high-pressure viscosity of 1-propyl-1-methyl-pyrrolidinium ([C₃C₁pyr]), 1-butyl-1-methyl-pyrrolidinium ([C₄C₁pyr]), and 1-hexyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)amide ([C₆C₁pyr]) cations with common anion, bis(trifluoromethylsulfonyl)amide ([NTf₂]), was measured up to a maximum CO₂ pressure of 25 MPa. In the temperature range investigated, the viscosity of the ionic liquid/ CO₂ mixture dramatically decreases with increasing of CO₂ pressure up to approximately 7 MPa but the viscosity decrease becomes less significant at higher CO₂ pressures (from 7 to 25 MPa) because the CO₂ composition in ILs slightly increases with pressure. At lower CO₂ pressures (compositions), temperature has a higher impact on the CO₂ solubility in IL, thus the viscosity drops significantly for lower temperatures (e.g. 298.15 K). The effect of alkyl chain length of the cation on the viscosity of ionic liquid/ CO₂ mixture was also measured. Though the pure [C_nC₁pyr][NTf₂] viscosity increases significantly with the increasing alkyl chain length of the cation, the viscosity of every ionic liquid/ CO₂ mixture tested herein become quite similar at higher CO₂ pressures, for a fixed temperature.

• Research Organization: Idaho National Lab. (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• Grant/Contract Number: DE-AC07-05ID14517
• OSTI ID: 1567699
• Report Number(s): INL/JOU-18-52343-Rev001; TRN: US2001048
• Journal Information: Journal of Chemical and Engineering Data, Vol. none, Issue none; ISSN 0021-9568
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
carbon dioxide
ionic liquid
viscosity