Carbon Dioxide Solubilities and Diffusivities in 1-Alkyl-3-methylimidazolium Tricyanomethanide Ionic Liquids: An Experimental and Modeling Study

Abstract

The solubility and diffusivity of CO2 in a series of 1-alkyl-3methylimidazolium tricyanomethanide ionic liquids ([C n mim]­[TCM] with n = 2, 4, 6, 7, 8; ILs) was studied using a magnetic suspension balance at temperatures ranging from 298 to 353 K and pressures up to 2 MPa. The effects of temperature, pressure, and alkyl chain length on CO2 solubility and diffusivity were examined. The electrolyte PC-SAFT (ePC-SAFT) equation of state was used to describe the solubility of CO2 in the ILs. The Henry’s law constant and the excess properties of solvation (Gibbs free energy, enthalpy, and entropy) were calculated. A series of equations derived from Fick’s second law were evaluated, and a Fourier expansion of Fick’s second law of diffusion was found to be the most suitable model for deriving diffusivities from gravimetric data. The diffusivities range from 10–10 to 10–9 m2·s–1 in the temperature and pressure ranges applied. The activation energies for CO2 diffusion (12–16 kJ·mol–1) were found to be in the range of traditional solvents.

Carbon Dioxide Solubilities in Decanoic Acid-Based Hydrophobic Deep Eutectic Solvents

“…One of the remarkable achievements in this context is the application of the nonvolatile ionic liquids (ILs) and their potential to replace volatile organic solvents for CO 2 capture. 5−9 ILs possess unique physicochemical properties, which are tunable by combining different cations and anions as well as inserting different functional groups in either the cation or the anion or in both.…”

Novel pressure and temperature swing processes for CO2 capture using low viscosity ionic liquids

“…A [TCM] absorption/desorption cycles [13] and the highly reduced production costs which have been proven by the manufacturer (Iolitec) in upscaling [TCM] − ILs to multiple hundred kilo gram capacity. Conceptual process layouts for capturing CO 2 from crude SNG with pressure swing, temperature swing and pressure-temperature-swing solvent regeneration options have been simulated using the Aspen Plus® simulator (V7.3.2 and V8.6) of Aspen Technology, Inc. (Cambridge, MA).…”

Effect of Cation Modification on the Physicochemical Properties and CO2 Solubility: Nonfluorinated Phosphonium-Based Ionic Liquids Incorporating a Dioctylsulfosuccinate Anion

“…The temperature was controlled using an overlapping controller involving a direct temperature controller (JUMO IMAGO 5000 and/or JULABO F-25ME) and a software controlled on the computer. The explanation of the measuring method, equipment, and sample preparation has been reported, 22 and the details of the measurement were presented in the Supporting Information.…”