Ionic liquids (ILs) have been proposed as potential inhibitors for preventing gas hydrate formation because their ion pairs effectively interrupt the hydrogen bonding between water molecules. ILs also have broad inhibitory capabilities depending on the specific cation and anion combinations. The final structural design of ILs for hydrate inhibition must be performed after an inhibition mechanism is suggested. In this study, the inhibitory thermodynamic effects of ILs were measured by the hydrate-aqueous liquid-liquid carbon dioxide (CO2) equilibrium, and the experimental results were analyzed based on the hydration free energy of ILs calculated through molecular dynamics study. 1-Hydroxyethyl-1-methylpyrrolidinum chloride showed the best inhibitory performance of the suggested candidates. The anions mostly contributed to the thermodynamic inhibition, but the cations had a marginal impact on CO2 hydrate inhibition. Through fundamental understanding of the inhibition mechanism by both experimental and computational approaches, it is highly possible to provide crucial information for effective ILs to be designed as the CO2 hydrate inhibitor.
Bibliographical noteFunding Information:
This research was a part of a project entitled “Development of Technology for CO 2 Marine Geological Storage” funded by the Ministry of Oceans and Fisheries, Korea . This work was also supported by the Human Resources Development Program (No. 2013401020060 0) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Trade, Industry and Energy. K.-S. Kim acknowledges support by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( 2012R1A1A2041510 ).
© 2014 Elsevier B.V.
- CO hydrate
- Hydration free energy
- Ionic liquid
- Thermodynamic inhibition
ASJC Scopus subject areas
- Chemical Engineering(all)
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry