Solubility of light alkanes and alkenes in ionic liquids |
| |
| Authors: | Rui ZHANG Shuyuan DONG Luo WU Zhichang LIU Chunming XU Haiyan LIU Xianghai MENG |
| |
| Affiliation: | State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China |
| |
| Abstract: | The solubility of light hydrocarbons in a variety of ionic liquids was studied, and it was found that ionic liquids containing Cu(Ⅰ) had higher solubility for hydrocarbons and alkene/alkane solubility selectivity, and Et3NHCl-2.1CuCl ionic liquid was preferred. The effects of temperature and pressure on the solubility of light hydrocarbons were investigated for the selected ionic liquid. It was found that low temperature and high pressure were favorable for the dissolution of light hydrocarbons, and the alkene/alkane solubility selectivity decreased with the increase of temperature and pressure. The alkene/alkane solubility selectivity was above 8.3 at the temperature of 30℃ and the pressure of 0.2 MPa. The initial dissolution rate of hydrocarbons in ionic liquid was large, but it decreased rapidly with prolonging time, and the dissolution rate of alkenes was higher than that of alkanes at the same conditions. The alkene/alkane separation selectivity increased with decreasing content of alkenes in the mixture of alkenes and alkanes. Light hydrocarbons dissolved in ionic liquids could be desorbed by means of increasing temperature, restoring the dissolution capability of ionic liquids to hydrocarbons. Alkanes were easier to be desorbed than alkenes, and small-molecule hydrocarbons were easier to be desorbed than large-molecule hydrocarbons. The desorption percentage exceeded 92% under optimal conditions. Ionic liquid had a good reusable performance in the absorption and separation of light alkanes and alkenes. The solubility only decreased by less than 5% when it was reused five times, and the alkane/alkane solubility selectivity was basically not affected by reusing times. Software Gaussian 09 was used to study the interaction between anions of ionic liquids and light alkanes and alkanes, and the solubility difference of light alkenes and alkanes in different ionic liquids was well explained. |
| |
| Keywords: | ionic liquid alkane alkene solubility absorption desorption |
|
| 点击此处可从《化工学报》浏览原始摘要信息 |
|
点击此处可从《化工学报》下载免费的PDF全文 |
|
