Orthogonal array design for the optimization of stripping Sr(II) from ionic liquids using supercritical CO₂

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• 作者：Tao Yang ; Jing Fu ; Qingde Chen ; Xinghai Shen ; ^{xshen@pku.edu.cn}
• 关键词：Supercritical CO2 stripping ; Ionic liquid ; Strontium ; Orthogonal array design
• 刊名：Chinese Journal of Chemical Engineering
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：25
• 期：1
• 页码：26-31
• 全文大小：597 K
• 卷排序：25

文摘

The strontium ions extracted from the aqueous phase into 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (C2mimNTf2) with dicyclohexyl-18-crown-6 (DCH18C6) was stripped effectively by supercritical CO2 (sc-CO2). Hexafluoroacetylacetone (HFAA)–acetonitrile was found to be an excellent modifier of sc-CO2 to enhance the stripping efficiency. In the orthogonal array design (OAD), OA25 (55) matrix was employed to optimize the stripping of Sr(II) from the DCH18C6–C2mimNTf2 system. Effects of five experimental factors: temperature, pressure, concentration of HFAA, static and dynamic extraction times as well as each factor at five-levels on the stripping of Sr(II) were optimized. The effects of these parameters were treated by the analysis of variance (ANOVA). The results showed that Sr(II) could be nearly 100% extracted from the IL phase at 308 K, 30 MPa, 40 min of dynamic extraction and 60 mmol·L− 1 HFAA in acetonitrile, respectively. Finally, the stripping mechanism was studied by ESI-MS.