2. Supercritical Fluids in Ionic Liquids

  1. Natalia V. Plechkova and
  2. Kenneth R. Seddon
  1. Maaike C. Kroon1 and
  2. Cor J. Peters2

Published Online: 14 MAR 2014

DOI: 10.1002/9781118839706.ch2

Ionic Liquids Further UnCOILed: Critical Expert Overviews

Ionic Liquids Further UnCOILed: Critical Expert Overviews

How to Cite

Kroon, M. C. and Peters, C. J. (2014) Supercritical Fluids in Ionic Liquids, in Ionic Liquids Further UnCOILed: Critical Expert Overviews (eds N. V. Plechkova and K. R. Seddon), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118839706.ch2

Editor Information

  1. The Queen's University of Belfast

Author Information

  1. 1

    Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, The Netherlands

  2. 2

    Chemical Engineering Program, The Petroleum Institute, Abu Dhabi, United Arab Emirates

Publication History

  1. Published Online: 14 MAR 2014
  2. Published Print: 20 MAR 2014

ISBN Information

Print ISBN: 9781118438633

Online ISBN: 9781118839706



  • chemical processes;
  • ionic liquids;
  • phase behaviour;
  • supercritical fluids


Ionic liquids and supercritical fluids are both alternative environmentally benign solvents, but their properties are very different. Ionic liquids are non-volatile but often considered highly polar compounds, whereas supercritical fluids are non-polar but highly volatile compounds. The combination of these two types of solvents has some unique features. It has been discovered that the solubility of supercritical carbon dioxide in several ionic liquids is very high but that the solubility of ionic liquids in supercritical carbon dioxide is negligibly low. Therefore, organic solutes can be extracted from an ionic liquid using supercritical carbon dioxide without any contamination by the ionic liquid. The phase behaviour of many binary or ternary (ionic liquid + supercritical carbon dioxide) systems was subsequently studied. Combined with the fact that ionic liquids are excellent reaction media for catalysed reactions, this led to the development of chemical processes where the reaction was carried out in the ionic liquid and the product was extracted afterwards with supercritical carbon dioxide. Newest developments include the multi-functional use of supercritical carbon dioxide as extraction medium, transport medium, and miscibility controller in these processes, resulting in higher reaction and separation rates.