M. Zare, A. Haghtalab, A. Ahmadi
Mar 15, 2013
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0
Influential Citations
63
Citations
Journal
Fluid Phase Equilibria
Abstract
Abstract Methane hydrate dissociation conditions in the presence of imidazolium based aqueous ionic liquid solutions including 1-buthyl-3-methylimidazolium methyl sulfate ([BMIM][MeSO 4 ]), 1-ethyl-3-methylimidazolium hydrogen sulfate ([EMIM][HSO 4 ]), 1-ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO 4 ]), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF 4 ]) and 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([OH-EMIM][BF 4 ]) are investigated. Isochoric method is used to measure experimental data in temperature range of 281.9–287.4 K and in pressure range of 7.08–12.16 MPa. The studied ionic liquids present a thermodynamic inhibition behavior on methane hydrate and cause to shift the hydrate equilibrium dissociation conditions to the higher pressures/lower temperatures. It is found that the most effective thermodynamic inhibitor is [OH-EMIM][BF 4 ] and among alkylsulfate-containing ionic liquids, the thermodynamic inhibition effects of two ionic liquids such as [EMIM][HSO 4 ] and [BMIM][MeSO 4 ] are better than that of [EMIM][EtSO 4 ]. Furthermore, the electrolyte cubic square-well equation of state (eCSW EoS) is coupled with the van der Waals–Platteuw model and applied to predict the hydrate dissociation pressures of the methane + ionic liquid + water systems. A good agreement between the results of the model with the experimental data indicates the reliability of this model to predict the hydrate equilibrium conditions.