Thermodynamics

Global phase behavior of imidazolium ionic liquids and compressed 1,1,1,2-tetrafluoroethane (R-134a)

  1. Wei Ren,
  2. Aaron M. Scurto*

Article first published online: 17 DEC 2008

DOI: 10.1002/aic.11657

Issue

AIChE Journal

AIChE Journal

Volume 55, Issue 2, pages 486–493, February 2009

Additional Information

How to Cite

Ren, W. and Scurto, A. M. (2009), Global phase behavior of imidazolium ionic liquids and compressed 1,1,1,2-tetrafluoroethane (R-134a). AIChE J., 55: 486–493. doi: 10.1002/aic.11657

Author Information

  1. Dept. of Chemical and Petroleum Engineering, NSF-ERC Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, KS 66045

*Dept. of Chemical and Petroleum Engineering, NSF-ERC Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, KS 66045

Publication History

  1. Issue published online: 12 JAN 2009
  2. Article first published online: 17 DEC 2008
  3. Manuscript Revised: 6 AUG 2008
  4. Manuscript Received: 4 MAY 2008

Funded by

  • DOT:KU Transportation Research Institute (TRI). Grant Number: DOT# DT0S59-06-G-00047
  • NSF-ERC Center of Environmentally Benign Catalysis. Grant Number: CEBC EEC-0310689

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

View Full Article (HTML) Get PDF (268K)

Keywords:

  • imidazolium ionic liquids;
  • R-134a;
  • global phase behavior;
  • high-pressure;
  • mixture critical points

Abstract

Novel processes involving ionic liquids with refrigerant gases have recently been developed. Here, the complete global phase behavior has been measured for the refrigerant gas, 1,1,1,2-tetrafluoroethane (R-134a) and 1-n-alkyl-3-methyl-imidazolium ionic liquids with the anions hexafluorophosphate [PF6], tetrafluoroborate [BF4] and bis(trifluoromethylsulfonyl)imide [Tf2N] from ∼0°C to 105°C and to 33 MPa. All of the systems studied were Type V from the classification scheme of Scott-van Konynenburg with regions of vapor-liquid equilibrium, miscible/critical regions, vapor-liquid-liquid equilibrium, and upper and lower critical endpoints (UCEP and LCEP). The effect of the alkyl chain length has been investigated, for ethyl-([EMIm]), n-butyl-([BMIm]), and n-hexyl-([HMIm]). With increasing chain length, the temperature of the lower critical end points increases and pressure at the mixture critical points decrease. With a common cation, the temperature of the LCEP increased and the mixture critical point pressures decreased in the order of [BF4], [PF6], and [Tf2N]. © 2008 American Institute of Chemical Engineers AIChE J, 2009

View Full Article (HTML) Get PDF (268K)