Influence of ionic liquid on polar organic compounds solubility in dense CO2 phase

Małgorzata Ewa Zakrzewska*, Yegor Borovkov, Ana Brandão Paninho, Zeljko Petrovski, Vesna Najdanovic-Visak, Ana Vital Morgado Nunes

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Accurate measurement and prediction of the phase behaviour of mixtures involved in a chemical process are crucial for its optimisation. Given the importance of CO2 conversion technologies and considering possible benefits of CO2-ionic liquid biphasic systems, i.e., facilitating a product separation, we investigated the high-pressure behaviour of components of interest in a recently developed process of cyclic carbonate synthesis directly from CO2 and potentially bio-based alcohols. The solubility of 1,2-butanediol and 1,2-butylene carbonate in a dense carbon dioxide phase was determined experimentally at the temperature of 313.2 K and pressures between 6 and 18 MPa. The influence of 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ionic liquid, [hmim][FAP], as a solvent, on the solubility of these compounds in CO2-rich phase, in ternary (CO2 + 1,2-butanediol + [hmim][FAP]), CO2 + butylene carbonate + [hmim][FAP]) and quaternary (CO2 + 1,2-butanediol + butylene carbonate + [hmim][FAP]) mixtures was investigated. The experimental results of the two binary systems were correlated using the density-based Chrastil equation. The knowledge of phase equilibria behaviours reported in this work will be useful for designing chemical conversions of carbon dioxide using [hmim][FAP] ionic liquid as reaction solvents.

Original languageEnglish
Article number106089
Number of pages6
JournalJournal of Supercritical Fluids
Early online date13 Oct 2023
Publication statusPublished - 1 Dec 2023

Bibliographical note

Copyright © 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (

Funding Information: This work was supported by Fundação para a Ciência e Tecnologia FCT/MCTES projects PTDC/EQU-EPQ/31926/2017 , UIDB/50006/2020 , and MIT-EXPL/CS/0052/2021 of the Associate Laboratory for Green Chemistry – LAQV , and UIDB/00100/2020 of the Centro de Química Estrutural – CQE . GC-FID data were obtained by the Analysis Laboratory LAQV/Requimte - Chemistry Department, FCT NOVA - Portugal.


  • Butanediol
  • Cyclic carbonate
  • High-pressure carbon dioxide
  • Multicomponent systems
  • Phase behaviour
  • Tris(pentafluoroethyl)trifluorophosphate ionic liquid


Dive into the research topics of 'Influence of ionic liquid on polar organic compounds solubility in dense CO2 phase'. Together they form a unique fingerprint.

Cite this