High-pressure solubility of carbon dioxide in pyrrolidinium-based ionic liquids: [bmpyr][dca] and [bmpyr][Tf2N]

Autor: Byung-Chul Lee, Sang Gyu Nam
Rok vydání: 2015
Předmět:
Zdroj: Korean Journal of Chemical Engineering. 32:521-533
ISSN: 1975-7220
0256-1115
DOI: 10.1007/s11814-014-0364-0
Popis: Solubility data of carbon dioxide (CO2) in two pyrrolidinium-based ionic liquids: 1-butyl-1-methylpyrrolidinium dicyanamide ([bmpyr][dca]) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpyr] [Tf2N]) are presented at pressures up to about 30MPa and temperatures from 303.2 K to 343.2 K. The solubility was determined by measuring bubble or cloud point pressures of mixtures of CO2 and ionic liquid using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The CO2 solubility in the ionic liquid in terms of the mole fraction or the molality increased with the increase of the equilibrium pressure at a given temperature, but decreased with the increase of temperature at a given pressure. At a given temperature, the mole fraction of CO2 dissolved in the ionic liquid increased rapidly as pressure increased. CO2 solubility in the mole fraction almost reached saturation around 0.65 for [bmpyr][dca] and around 0.8 for [bmpyr][Tf2N], respectively. The experimental data for the CO2+ ionic liquid systems were correlated using the Peng-Robinson equation of state (PR-EoS). The mixing rules of the Wong-Sandler type rather than the classical mixing rules of the van der Waals type were coupled with the PR-EoS. The resulting modeling approach proved to be able to correlate the CO2 solubilities in aforementioned ionic liquids over the aforementioned range of temperature and pressure within 5% average deviations.
Databáze: OpenAIRE
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