%P 2165-2188
%T Ionic liquids for the inhibition of gas hydrates. A review
%I Springer Science and Business Media Deutschland GmbH
%V 20
%A I. Ul Haq
%A A. Qasim
%A B. Lal
%A D.B. Zaini
%A K.S. Foo
%A M. Mubashir
%A K.S. Khoo
%A D.-V.N. Vo
%A E. Leroy
%A P.L. Show
%O cited By 17
%L scholars16721
%J Environmental Chemistry Letters
%D 2022
%N 3
%R 10.1007/s10311-021-01359-9
%X The formation of gas hydrates is a major issue during the operation of oil and gas pipelines, because gas hydrates cause plugging, thereby disrupting the normal oil and gas flows. A solution is to inject gas hydrate inhibitors such as ionic liquids. Contrary to classical inhibitors, ionic liquids act both as thermodynamic inhibitors and hydrate inhibitors, and as anti-agglomerates. Imidazolium-based ionic liquids have been found efficient for the inhibition of CO2 and CH4 hydrates. For CO2 gas hydrates, N-ethyl-N-methylmorpholinium bromide showed an average depression temperature of 1.72 K at 10 wt concentration. The induction time of 1-ethyl-3-methyl imidazolium bromide is 36.3 h for CO2 hydrates at 1 wt concentration. For CH4 hydrates, 1-ethyl-3-methyl-imidazolium chloride showed average depression temperature of 4.80 K at 40 wt. For mixed gas hydrates of CO2 and CH4, only quaternary ammonium salts have been studied. Tetramethyl ammonium hydroxide shifted the hydrate liquid vapour equilibrium to 1.56 K at 10 wt, while tetrabutylammonium hydroxide showed an induction time of 0.74 h at 1 wt concentration. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.