American Chemical Science Journal, ISSN: 2249-0205,Vol.: 2, Issue.: 3 (July-September)
Study on Prompt Methane Hydrate Formation Derived by Addition of Ionic Liquid
Takashi Kitajima1, Naoto Ohtsubo1, Shunsuke Hashimoto1, Takashi Makino2, Daisuke Kodama3 and Kazunari Ohgaki1* 1Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
2National Institute of Advanced Industrial Science and Technology, 4-2-1 Nigatake, Miyagino, Sendai, Miyagi 983-8551, Japan.
3Department of Chemical Biology and Applied Chemistry, College of Engineering, Nihon University, Koriyama, Fukushima, 963-8642, Japan.
Takashi Kitajima1, Naoto Ohtsubo1, Shunsuke Hashimoto1, Takashi Makino2, Daisuke Kodama3 and Kazunari Ohgaki1*
1Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
Aims: The objective of this study is to establish the fundamental model on methane hydrate formation and to accelerate the rate of methane hydrate formation with a small amount of ionic liquid and to investigate the effect of ionic liquid on hydrate formation.
Study Design: Experimental study containing modeling.
Place and Duration of Study: The present study was held between April 2010 and February 2012 at Division of Chemical Engineering, Department of Materials Engineering Science, Osaka University.
Methodology: Methane hydrate formation was modelized based on the driving force, fugacity difference before and after hydrate formation. BMIM-hexafuorophosphate (BMIM-PF6) was adopted as a representative of 1-butyl-3-methylimidazolium (BMIM) salts. The temperature dependence of methane hydrate formation rate was investigated and activation energy of hydrate formation was evaluated for the pure water and BMIM-PF6 aqueous solution systems.
Results: An addition of small amount of BMIM-PF6 is able to accelerate the methane hydrate formation. The pseudo-first order reaction model is applicable to the methane hydrate formation in both the pure water and BMIM-PF6 aqueous solution systems. The activation energies of methane hydrate formation are large negative values in the both systems, that is, the methane hydrate formation process is considered to be composed of the precursory hydration and succeeding hydrate formation. A very small amount of BMIM-PF6 seems to change the interfacial energy between guest molecules and precursor or initial hydrate particles without the change of the activation energy for overall methane hydrate formation.
Methane hydrate; hydration kinetics; ionic liquid; modeling on hydration; acceleration on hydration.
Full Article - PDF Page 100-110
DOI : 10.9734/ACSJ/2012/1512Review History Comments