Determination of activity coefficients at infinite dilution of organic solutes in the ionic liquid, tributylmethylphosphonium methylsulphate by gas–liquid chromatography

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• 作者：Trevor M. Letcher ; Prashant Reddy
• 关键词：Ionic liquids ; Activity coefficient at infinite dilution ; Gas– ; liquid chromatography ; Extractive distillation
• 刊名：Fluid Phase Equilibria
• 出版年：2007
• 出版时间：25 October 2007
• 年：2007
• 卷：260
• 期：1
• 页码：23-28
• 全文大小：131 K

文摘

Activity coefficients at infinite dilution, 389843"">, have been determined for organic solutes in the phosphonium-based ionic liquid, tributylmethylphosphonium methylsulphate at T = 308.15 K, 318.15 K and 328.15 K. The experimental activity coefficient data presented are the first to be reported for this ionic liquid, through the use of the technique of steady-state gas–liquid chromatography. The organic solutes that were investigated were normal alkanes (pentane, hexane, heptane and octane), alkenes (1-hexene, 1-heptene and 1-octene), alkynes (1-hexyne, 1-heptyne and 1-octyne), cycloalkanes (cyclopentane, cyclohexane and cycloheptane) and benzene. The partial molar excess enthalpies at infinite dilution, , were also determined for the solutes from the temperature dependency of the values.

The 409ceb9e376dedf789""> data obtained for tributylmethylphosphonium methylsulphate in this investigation have been compared to those obtained for other ionic liquids available in literature; most notably that of trihexyl(tetradecyl)-phosphonium tris(pentafluoroethyl) trifluorophosphate. This comparison allows for an assessment of the potential for the use of different ionic liquids as solvents in industrial solvent-enhanced separation processes such as extractive distillation.