CO2 enclathration in the presence of water-soluble hydrate promoters: Hydrate phase equilibria and kinetic studies in quiescent conditions

Clathrate hydrates have potential applications in various domains and particularly for CO2 capture where the search for additives able to speed up hydrate formation is of scientific, technological and economical interest. This study investigates the potentialities of two additives used in combination for enhancing CO2 enclathration rates: a surfactant (sodium dodecyl sulphate; SDS) and an organic compound (tetrahydrofuran; THF). Experiments performed in batch and in semi-continuous reactor configuration, reveal that this combination of additives efficiently promotes hydrate formation, allowing a full water-to-hydrate conversion despite the quiescent-forming conditions used. The possible action mechanisms of this combination of additives are analyzed and discussed on the basis of experimental data of hydrate phase equilibria (with and without additives), visual observations, and kinetics experiments.

► Search of efficient additives for CO2 capture processes using clathrates hydrates.
► Experimental results based on phase equilibria, kinetics and visual observations.
► Action mechanisms linked to these additives are analysed and discussed.
► Mixed CO2+THF hydrate promote the formation of the single CO2 hydrate.
► Potentialities of this combination of additives (SDS+THF) are demonstrated.