ABSTRACT

Ionic liquids are attracting great attention nowadays due to their interesting properties which make them useful in a broad range of applications including reaction media or separation/capture of environmentally hazardous gases such as carbon dioxide. In many cases, for practical and/or economical reasons, the use of aqueous solutions of ILs would be preferable to their use as pure compounds. In this work, high pressure equilibrium data for the {carbon dioxide (CO2) + tri-iso-butyl(methyl)phosphonium tosylate [iBu3MeP][TOS] + water system were measured at temperatures ranging from (276 to 370) K and pressures up to 100 MPa. Measurements were performed using a high-pressure cell with a sapphire window that allows direct observation of the liquid vapour transition. Mixtures with different IL concentrations were studied in order to check the influence of the amount of IL on the solubility of CO2 in the aqueous mixture. The results show that the presence of IL enhances the solubility of CO2 in the (IL + water) system revealing a salting-in effect of the IL on the solubility of CO2. The appearance of a three phase region was observed for IL concentrations higher than 4 mol% of IL in water when working at pressures between 4 and 8 MPa and temperatures between (280 and 305) K. In this range, the upper limit of the VLE region observed is shown to increase with the temperature being almost independent of the IL initial concentration in the mixture.

Compounds

#	Formula	Name
1	H2O	water
2	C20H37O3PS	triisobutylmethylphosphonium p-toluenesulfonate
3	CO2	carbon dioxide

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	1 2	Viscosity, Pa*s ; Liquid	Mass fraction - 2; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	CONPLT:UFactor:8	8
POMD	3 1 2	Vapor or sublimation pressure, kPa ; Liquid	Temperature, K; Liquid Solvent: Mole fraction - 2; Liquid Mole fraction - 3; Liquid		Liquid Gas	CCELL:UFactor:32	110
POMD	3 1 2	Triple point temperature, K ; Liquid mixture 1	Pressure, kPa; Liquid mixture 1 Solvent: Mole fraction - 2; Liquid mixture 1		Liquid mixture 1 Liquid mixture 2 Gas	VISOBS	41

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

High pressure solubility data of carbon dioxide in (tri-iso-butyl(methyl)phosphonium tosylate + water) systems

Ventura, S. P. M.[Sonia P. M.], Pauly, J.[Jerome], Daridon, J. L.[Jean L.], Silva, J. A. L. d., Marrucho, I. M.[Isabel M.], Dias, A. M. A.[Ana M.A.], Coutinho, J. A. P.[Joao A. P.]

ABSTRACT