Separation of thiophene from octane/hexadecane with ionic liquids in ternary liquid-liquid phase equilibrium

• Published in: Fluid phase equilibria Vol. 509; p. 112467
• Main Authors: Durski, Marcin, Naidoo, Paramespri, Ramjugernath, Deresh, Domańska, Urszula
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2020
• Subjects: 1-Butyl-1-methylpiperidynium dicyanamide; Ionic liquids; NRTL correlation; Selectivity; Solute distribution ratio; Ternary (liquid-liquid) phase equilibrium; Tri-iso-butylmethylphosphonium tosylate; Tri-iso-butylmethylphosphonium tosylate; Ionic liquids; Solute distribution ratio; 1-Butyl-1-methylpiperidynium dicyanamide; Ternary (liquid-liquid) phase equilibrium; Selectivity; NRTL correlation
• ISSN: 0378-3812; 1879-0224
• DOI: 10.1016/j.fluid.2020.112467

This work is a continuation of the investigations on desulfurization processes by assessing the applicability of two ionic liquids (ILs), 1-butyl-1-methylpiperidynium dicyanamide, [BMPIP][DCA] and tri-iso-butylmethylphosphonium tosylate, [Pi4,i4,i4,1][TOS], for the separation of thiophene from octane, or hexadecane. The latter two components are used as model substances of the fuel stream. Experimental liquid-liquid phase equilibrium (LLE) data were obtained for four ternary systems {IL + thiophene + octane, or hexadecane} at temperature T = 308.15 K and pressure p = 101 kPa. The DCA-based IL showed better selectivity than the tosylate-based IL in the extraction of thiophene from both alkanes with much lower solute distribution ratio. The selectivity is acceptable in all systems in comparison with currently published data for different ILs. Chromatography analysis showed that the IL was not present in the octane, or hexadecane layer, which simplifies the process of separating the solvent from the hydrocarbon layer. The non-random two liquid (NRTL) model showed satisfactory correlation of the measured phase data.