Solubility of CO2 in Methanol, 1-Octyl-3-methylimidazolium Bis（trifluoromethylsulfonyl）imide, and Their Mixtures

• Published in: 中国化学工程学报：英文版 2013 (3), p.310-317
• Main Author: 雷志刚 张本凤 朱吉钦 宫万福 吕建宁 李延生
• Format: Article
• Language: English
• Subjects: 二氧化碳; 混合物; 溶解度数据; 甲基咪唑; 甲醇; 磺酰基; 辛基; 酰亚胺
• ISSN: 1004-9541; 2210-321X

Solubility data of carbon dioxide （CO2） （1） in methanol （2）, 1-octyl-3-methylimidazolium bis（trifluoro- methylsulfonyl）imide （[omim]＋[TfzN]-） （3）, and their mixtures （w3 = 0.2, 0.5, and 0.8） at temperatures 313.2 and 333.2 K and pressures up to 7.0 MPa were measured by a high-pressure view-cell technique. The solubility of CO2 in methanol （w3 = 0）, [omim]＋[Tf2N]- （w3 = 1.0） and their mixtures follows the order of （w3 = 0）〈（w3 = 0.2）〈 （w3 = 0.5）〈（w3 = 0.8）〈（w3 = 1.0） at the same temperature and pressure, while the magnitude of Henry＇s constants follows the reverse order at a given temperature, which is consistent with the COSMO-RS （conductor-like screen- ing for real solvents） calculation. The solubility data of CO2 in methanol and [omim]~[Tf2N]- are correlated with the Peng-Robinson equation of state, and the solubility of CO2 in the mixtures of methanol and [omim]＋[TfzN] can be well predicted based on the mole fraction average of methanol and [omim]＋[Tf2N] over the solubility of CO2 in pure methanol and [omim]＋[Tf2N] . The mixtures of methanol and [omim]＋[Tf2N]- may be used as physical solvents for capturing CO2 with high partial pressures since they combine the advantages of organic solvents and ionic liquids.