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 (0.1481/0.3952/0.7501mol fraction)+H2 (0.8519/0.6048/0.2499mol fraction) in the presence of water or 0.05 and 0.30 mass fractions tetra-n-butylammonium bromide (TBAB) aqueous solutions and CO2 (0.4029mol fraction)+CH4 (0.5971mol 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 275.5–292.8K up to 15.91MPa. 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.