Repozytorium publikacji - Politechnika Gdańska

Regular solution theory (RST) is the most popular model for the interpretation of the interaction between CO2 and ionic liquids. In the present work, the parameters of this model were determined for the CO2 absorption in eleven imidazolium ionic liquids. The y-intercept (A) of the RST model for the investigated imidazolium liquids increases with increasing temperature whereas the slope (B) remains constant. The values of RST parameters strongly depend on the Hildebrand parameters of the ionic liquids. It has been shown that ionic liquids surface tension and molar volume are the decisive parameters. The influence of the type of fluorinated anion and the length of the alkyl substituent on the solubility of CO2 was investigated. The dispersion of charge and the free space between the ions are key parameters determining the gas dissolution. The partial molar entropy and enthalpy of solvation were determined using a modified temperature dependent function of Henry's constant. It has been shown, that determination coefficient of the Henry's relation has to be larger than 0.9999 in order to estimate heat of salvation reliably. The molar enthalpy of solvation ranged from −11.6 to −14.7 kJ mol−1 at 298 K. Moreover, it is proposed that the entropy is composed of two parts, which explains the decrease in system order along with the elongation of the alkyl chain of the imidazolium substituent. Thus, the decrease of the gas condensation entropy component explains the increase of the partial molar entropy of solvation with temperature. It was shown that the molar volume of theoretically liquefied CO2 in the ionic liquid is lower than the actual value.

Autorzy

• Bartosz Dębski,
• Andreas Hänel,
• dr inż. Robert Aranowski link otwiera się w nowej karcie ,
• Stefan Stolte,
• Marta Markiewicz,
• Thomas Veltzke,
• dr inż. Iwona Cichowska-Kopczyńska link otwiera się w nowej karcie