In this study, we investigated the kinetics of CH4 hydrate formation in the presence of ionic liquid (IL). 1-hydroxyethyl-1-methylmorpholinium chloride (HEMM-Cl) was chosen as a material for the kinetic promotion effect test. Equilibrium hydrate dissociation pressures for CH4 hydrate with aqueous HEMM-Cl solution was measured. Its induction time and consumed amount of CH4 gas were also obtained. Equilibrium dissociation curve of CH4 hydrate with 10 wt% of HEMM-Cl were shifted toward higher pressure and lower temperature region, which means that HEMM-Cl shows the effect of thermodynamic inhibition. In addition, aqueous solutions containing 20~20,000 ppm of HEMM-Cl was prepared and experiments of hydrate formation kinetics were conducted at 70 bar and 274.15 K. Results showed that there was no induction time on CH4 hydrate formation when IL was added. The amount of consumed CH4 was increased with the whole range of tested concentration of IL. At 1,000 ppm of HEMM-Cl concentration, the highest CH4 consumption happened, and this means that HEMM-Cl could be a kinetic promoter to enhance the CH4 hydrate formation. To compare its performance of kinetic promotion on hydrate formation, the well-known surfactant promoter SDS (sodium dodecyl sulfate) was also tested at the same temperature and pressure condition. Results showed that shorter induction time and larger amount of gas consumption was obtained for HEMM-Cl than for SDS. According to the result, it is expected that this ionic liquid could be applied for the development of gas storage method using gas hydrates.

Kinetic promotion effection of ionic liquid on CH4 hydrate formation

251st National Meeting (2016)

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