Solubility and Diffusion of H₂S and CO₂ in the Ionic Liquid 1-(2-Hydroxyethyl)-3-methylimidazolium Tetrafluoroborate

Abstract

The solubilities and diffusion coefficients of hydrogen sulfide and carbon dioxide gases in the ionic liquid (IL) 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([hemim][BF 4 ]), at temperatures ranging from (303.15 to 353.15) K and pressures up to 1.1 MPa, were determined. The solubility data were correlated using the Krichevsky-Kasarnovsky equation, and Henry's law constants at different temperatures were obtained. From the solubility data, the partial molar thermodynamic functions of solution such as Gibbs energy, enthalpy, and entropy were calculated. The diffusion coefficients were obtained for H 2 S and CO 2 using a semi-infinite volume approach, and a correlation equation with temperature is presented for each gas. A comparison showed that the solubility of H 2 S was about three times its magnitude, and its diffusion coefficient is of the same order of magnitude as that of CO 2 in the IL studied in this work.

Solubility and diffusion of CO2 and H2S in the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate

“…In each case a value of R 2 > 0.99 was obtained, which indicates that there exists quite good internal consistency between the experimental data obtained. The Krichevsky-Kasarnovsky equation [28], modified for solvents of negligible vapour pressure [21][22][23], was used to model the experimental results obtained in this work:…”

“…Time intervals greater than 2 min were used so that any surface adsorption not in equilibrium with the gas would not affect the values obtained for the diffusion coefficients. The validity of assumptions 1 and 3 has been fully discussed in our previous work [23]. The validity of assumption 2 was checked mathematically for the two systems studied in this work using equation (4) to determine the concentration of the solute at the bottom of the autoclave at the final diffusion time.…”

“…The diffusion coefficients of H 2 S and CO 2 gases in the IL were measured by the apparatus described in our previous work [23] and the method devised by Camper et al [8]. By this method, the diffusion measurements were made through measurement of pressure with respect to time during the first 20 min in which the magnetic stirrer was turned off so that there would be a stagnant layer of ionic liquid.…”

Solubility of CO2 in 1-(2-hydroxyethyl)-3-methylimidazolium ionic liquids with different anions

“…In a subsequent work, they concluded that CO 2 /IL complexations are not the sole controlling factor in relative CO 2 solubility and the energies of vapourisation and molar volumes appear to be determining factors in relative CO 2 solubility in ILs [8]. Later they reported the solubility in the form of Henry's law constants and diffusion of CO 2 at five discrete temperatures from [19] and other [emim] based ILs, which are reported in the literature.…”

Perspectives of Ionic Liquids Applications for Clean Oilfield Technologies

“…During the present century, a big number of studies have been performed to explore the prospects of ILs for gases separation and for founding the best prototypes for CO 2 capture (Bates et al, 2002, Baltus et al, 2004, Baltus et al, 2005, Shiflett & Yokozeki, 2005, Jacquemin et al, 2006, Hou & Baltus, 2007, . Schilderman et al, 2007, Yokozeki & Shiflett, 2007, Sánchez et al, 2007, Ventura et al, 2008, Camper et al, 2008, Soriano et al, 2008, Soriano et al, 2009, Heintz et al, 2009, a, b. Carvalho et al, 2009, Kuleman et al, 2010, Shokouhi et al, 2010 and also several discoveries have been patented (Brennecke & Maginn, 2002, Davis Jr., 2004, Chinn et al, 2006. Oleffin/paraffin separation is other very important separation process in refineries.…”