High pressure phase behavior of carbon dioxide in 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)New standards concerning environmental and safety issues are creating an increasing interest on ionic liquids as alternative solvents for a wide range of industrial applications. In this work, a new apparatus developed to measure vapor-liquid phase equilibrium in a wide range of pressures and temperatures was used to measure the phase behavior of the binary systems of carbon dioxide (CO(2))+1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide ([C(2) mim][Tf(2)N]) and CO(2)+1-methyl-3-pentyl-imidazolium bis(trifluoromethylsulfonyl)imide ([C(5) mim][Tf(2)N]) at temperatures up to 363 K and pressures up to 50 MPa. A thermodynamic consistency test, developed for systems with incomplete PTxy data and based on the Gibbs-Duhem equation, was applied to the experimental data measured in this work and the Peng-Robinson EoS using the Wong-Sandler mixing rule was used to describe the experimental data with excellent results. (C) 2008 Elsevier B.V. All rights reserved.48299107Fundacao para a Ciencia e a Tecnologia [POCI/EQU/58152/2004]Pedroj. Carvalho [SFRH/BD/41562/2007]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao para a Ciencia e a Tecnologia [POCI/EQU/58152/2004]Pedroj. Carvalho [SFRH/BD/41562/2007]FAPESP [2006/03711-1