Procedia Engineering 42 (2012) 1229 – 1241 1877-7058 © 2012 Published by Elsevier Ltd. doi:10.1016/j.proeng.2012.07.515 20 th International Congress of Chemical and Process Engineering CHISA 2012 25 – 29 August 2012, Prague, Czech Republic Mutual solubilities of ammonium-based ionic liquids with water and with water/methanol mixture K. Machanová a , J. Jacquemin b , Z. Wagner a a*, M. Bendová a a E. Hála Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals AS CR, v. v. i., Rozvojová 2/135, 16502 Praha 6, Czech Republic b QUILL Research Centre, Queen’s University of Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG Northern Ireland, UK Abstract Over the last two decades, ionic liquids have gained importance as alternative solvents to conventional VOCs in the field of homogeneous catalysis. This success is not only due to their ability to dissolve a large amount of metal catalysts, but it is also due to their potential to enhance yields of enantiopure products. The art of preparation of a specific enantiomer is a highly desired one and searched for in pharmaceutical industry. This work presents a study on solubility in water and in water/methanol mixture of a set of ILs composed of the bis(trifluoromethylsulfonyl)imide anion and of the N-alkyl-triethyl-ammonium cation (abbrev. [N R,222 ][NTf 2 ]) with the alkyl chain R ranging from 6 to 12 carbons. Mutual solubilities between ILs and water, as well as between ILs and methanol/water mixture were investigated in detail. These solubilities were measured using two well-known and accurate experimental techniques based on a volumetric and a cloud-point methods. Both methods enabled us to measure the Tx diagrams reflecting the mutual solubilities between water (or water/methanol) and selected ILs in the temperature range from 293.15 to 338.15 K. The data were fitted by using the modified Flory-Huggins equation proposed by de Sousa and Rebelo and compared also with the prediction carried out by the Cosmo-RS methodology. © 2012 Published by Elsevier Ltd. Selection under responsibility of the Congress Scientific Committee (Petr Kluson) Keywords: Ionic liquids; liquid-liquid equilibria; solubility; COSMO-RS; modified Flory-Huggins equation; gnostic regression * Corresponding author. Tel.: +420 220 390 290; fax: +420 220 920 661. E-mail address: wagner@icpf.cas.cz. Available online at www.sciencedirect.com