TITLE:
CO2 Capture at Room Temperature and Ambient Pressure: Isomer Effect in Room Temperature Ionic Liquid/Propanol Solutions
AUTHORS:
Hiroshi Abe, Azusa Takeshita, Hirokazu Sudo, Koichi Akiyama, Hiroaki Kishimura
KEYWORDS:
CO2 Capture, Room Temperature Ionic Liquids, Propanol Isomer Effect, Torsion Angle of TFSI- Anion
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.6 No.2,
May
25,
2016
ABSTRACT: A CO2 capture system without supercritical CO2 was
optimized for mixtures of hydrophobic room temperature ionic liquids (RTILs) and
propanol. We tested RTILs using bis(trifluoromethanesulfonyl)imide, TFSI-,
anion and four quaternary ammonium cations, two quaternary phosphonium cations,
and one imidazolium cation. The addition of 2-propanol into the RTILs clearly
promoted the capture of normal CO2(nCO2) at ambient temperature and pressure. When combined
with 2-propanol, the most efficient RTILs for nCO2 capture were N-butyl-N,N,N-trimethylammonium TFSI-.
This enhancement of nCO2 capture was not observed in RTIL mixtures with 1-propanol or in propanol
mixtures containing other phosphonium- and imidazolium-based RTILs. The torsion
angle of TFSI-, which was calculated using density functional
theory, is thought to be related to high nCO2 capture efficiently.