Semi-clathrate hydrate phase equilibrium measurements for the CO2+H2/CH4+tetra-n-butylammonium bromide aqueous solution system

In this communication, clathrate/semi-clathrate hydrate dissociation conditions for the systems containing mixtures of CO2 (0.1481/0.3952/0.7501 mol fraction)+H2 (0.8519/0.6048/0.2499 mol fraction) in the presence of water or 0.05 and 0.30 mass fractions tetra-n-butylammonium bromide (TBAB) aqueous solutions and CO2 (0.4029 mol fraction)+CH4 (0.5971 mol fraction) in the presence of water, 0.05 and 0.3 mass fractions TBAB have been measured and are reported. An apparatus comprising a high pressure equilibrium cell as the main part has been employed for the measurements following the isochoric pressure-search method. The range of conditions for the measurements are 275.5–292.8 K up to 15.91 MPa. Significant decrease in operating pressure of gas hydrate formation for separation of CO2 from the corresponding gas mixtures is observed due to the promotion effects of TBAB.

► Phase equilibria of semi-clathrate hydrates of mixtures of gases were measured. ► The data are for the CO2+H2/CH4+water/TBAB aqueous solution systems. ► The isochoric pressure search method was pursued for performing the measurements. ► The hydrate promotion effects of TBAB are discussed.