Dialkylimidazolium halide ionic liquids as dual function inhibitors for methane hydrate

An improved model for the phase equilibrium of methane hydrate inhibition in the presence of ionic liquids

“…The developed phase stability model is validated with experimental data on the phase stability conditions form methane hydrate in the presence of 21 ILs as reported in literatures [7,[11][12][13]15,16,21]. The ILs considered are from different ionic family such as, tetraalkylammonium, pyrrolidinium, imidazolium cationic family with various anion group such as halides (Cl, Br, I), sulphate (HSO 4 , ethylsulphate), tetrafluoroborate (BF 4 ) and dicyanamide (DCA).…”

“…Further, the developed liquid phase activity model is used to compute the fugacity of the liquid phase, and the fugacity of hydrate phase is computed from modified van der Waals and Platteuw model coupled with PR-EoS which is used for fugacity of hydrate former (gas phase) for the prediction of methane hydrate phase stability conditions in the presence of ILs. The model predictions are compared with experimental results on the phase stability of methane hydrate reported in open literatures for 21 ILs [7,[11][12][13]15,16,21]. The effect of 21 ILs with different concentration range from 5% to 20% (Table 1) are chosen from various ionic groups such as tetraalkylammonium, pyrrolidinium, imidazolium cationic family with various anion group such as halides (Cl, Br, I), sulphate (HSO 4 , ethylsulphate), tetrafluoroborate (BF 4 ) and dicyanamide (DCA), are considered from open literature for modeling the phase stability of methane hydrate inhibition.…”

“…The ILs in the presence of water showed significant effect on both ILs and water structures which further influence the IL-water phase behavior (IL aqueous solution activity) [8,9]. These ILs are used as LDKIs and thermodynamic inhibitors for methane hydrate formation [10,11]. Xiao et al [11] reported that imidazolium-based ILs having halides as anion showed significant dual function performance as the kinetic and thermodynamic inhibitors on the methane hydrate formation.…”

“…These ILs are used as LDKIs and thermodynamic inhibitors for methane hydrate formation [10,11]. Xiao et al [11] reported that imidazolium-based ILs having halides as anion showed significant dual function performance as the kinetic and thermodynamic inhibitors on the methane hydrate formation. Their study revealed that ILs must have strong electrolyte charges and capable of hydrogen bonding with the water molecule which causes the shift in H-L-V equilibrium conditions to a lower temperature at a given pressure and also slow down the hydrate nucleation growth rates.…”

Synthesis and application of a novel combined kinetic hydrate inhibitor

“…Various kinds of KHIs have been developed, such as poly(vinylpyrrolidone) (PVP) [8,9] and polyvinylcaprolactan (PVCap) [10,11], which represent the inhibitors of low dosage, high efficiency and low cost. Moreover, antifreeze proteins [12,13] and ionic liquids [14][15][16] etc. as hydrate inhibitors provide a guideline for the development of new green KHIs recently.…”