High pressure densities for mixed ionic liquids having different functionalities: 1-butyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. (May 2017)

• Record Type: Journal Article
• Authors: Hiraga, Yuya; Koyama, Kento; Sato, Yoshiyuki; Smith, Richard L.
• Is Part Of: Journal of chemical thermodynamics. Volume 108(2017)
• Page Start: 7
• Page End: 17
• Publication Date: 2017-05
• Subjects: High pressure density -- Equation of state -- Mixed ionic liquid -- Biomass-soluble ionic liquid -- CO2-soluble ionic liquid; Thermodynamics -- Periodicals; Thermochemistry -- Periodicals; Thermodynamique -- Périodiques; Thermochimie -- Périodiques; Thermochemistry; Thermodynamics; Periodicals; 541.369
• DOI: 10.1016/j.jct.2016.12.037
• Languages: English
• ISSNs: 0021-9614

Abstract

Graphical abstract: Highlights: Physical properties of mixed ionic liquids having different functionality. Experimental densities at pressures up to 200 MPa. Mixed ionic liquids decomposed according to their pure decomposition temperatures. Atmospheric and high pressure densities and viscosities show regular trends. Two general methods for correlation and prediction are proposed. Abstract: In this work, high pressure density measurements were made of mixed ionic liquid systems (1-butyl-3-methylimidazolium chloride ([bmim]Cl) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf2 N])) for the purpose of developing efficient reaction and separation systems for processing biomass. The mixed ionic liquids were prepared at mole ratios, [bmim]Cl:[bmim][Tf2 N] of 0.75: 0.25, 0.50: 0.50 and 0.25: 0.75. Density data were measured (10–200 MPa, 312–392 K) and correlated (up to 100 MPa) with the ε ∗ -modified Sanchez-Lacombe equation of state ( ε ∗ -mod SL EoS). The density of the binary mixed ionic liquid system was modeled in two ways: (i) as a single pseudo-component or (ii) as two discrete components. By treating the mixed ionic liquids as a single pseudo-component, the ε ∗ -mod SL EoS could correlate the high pressure density data to within a maximum average relative deviation (ARD) of 0.06%. On the other hand, by treating the mixed ionic liquids as discrete components, higher ARD values (0.15%) were obtained from the ε ∗ -mod SL EoS that can be attributed to the EoS mixing rules. Both approaches for modeling the ionic liquid mixtures had sufficiently low deviations and will be applied to multicomponent CO2 -containing systems in future works.