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

作者：Lee Byung Chul^*; Nam Sang Gyu

来源：Korean Journal of Chemical Engineering, 2015, 32(3): 521-533.

DOI：10.1007/s11814-014-0364-0

• Solubility
• Carbon Dioxide (CO2)
• Ionic Liquid
• Pyrrolidinium
• Correlation
• Peng-Robinson Equation of State
• Wong-Sandler Mixing Rules

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.

• 出版日期2015-3