An SF6 purification process utilizing gas hydrate formation developed for electric power industry

Effects of Salinity on Hydrate Phase Equilibrium and Kinetics of SF6, HFC134a, and Their Mixture

“…In recent years, researchers have reported the use of SF 6 mixture gas to improve the hydrate formation rate and thermodynamics, such as SF 6 /CO 2 , 18 and SF 6 /N 2 . 20 However, the formation of SF 6 /HFC134a hydrate has not been studied in term of its potential application to water desalination, despite having confirmed the thermodynamic and kinetic feasibility of pure 1,1,1,2-tetrafluoroethane (HFC134a) and SF 6 hydrates through laboratory-scale experiments. 3,11,17,21 Considering the results of previous studies, the HFC134a/SF 6 mixture is expected to significantly lower the hydrate equilibrium compared with pure SF 6 hydrate.…”

Kinetic Selectivity of SF6 during Formation and Dissociation of SF6 + N2 Hydrates and Its Significance in Hydrate-Based Greenhouse Gas Separation

“…36 The system box was composed of 4 × 3 × 3 replicated sII hydrate. The small (5 12 ) cages were filled with N 2 molecules with a fractional cage occupancy of 0.26, whereas the large (5 12 6 4 ) cages were filled with both N 2 and SF 6 molecules with fractional cage occupancy values of 0.025 and 0.975, respectively, considering the cage occupancy values of the SF 6 + N 2 hydrate obtained from our previous study. 14 The overall system box was confined to 13.7 × 5.2 × 5.2 (nm 3 ).…”

“…16,19−21 Hydrate-based gas separation (HBGS) has been proposed as one of the promising methods for capturing greenhouse gases, and its feasibility has been confirmed by several researchers. 7,[10][11][12][13][14]16 According to our previous study, the hydrate method required a remarkably lower initial SF 6 concentration and pressure than the liquefaction method to provide a specified recovery ratio of SF 6 . 14 Many previous HBGS studies have focused on the equilibrium-stage separation covering phase equilibria of mixed clathrate hydrates, separation efficiency at an equilibrium state, and the equilibrium recovery ratio.…”

Tritiated Sulfur Hexafluoride Disposition Strategies

“…SF6 purification is a well-established technology and there are several commercially available purification methods that SF6 users can choose from to meet their purification needs for non-radioactive decomposition products. 31,32,33 Detritiation technologies are also widely studied, however tritium systems are much less common in industry. 34 The overlap of the two technologies is confined to a series of publications on the International Thermonuclear Experimental Reactor (ITER) Neutral Beam Injector (NBI) system and the Tokamak Fusion Test Reactor (TFTR) Neutral Beam source.…”

“…Ahn et al reports the formation of SF6 hydrates for the purpose of separating SF6 from N2 and O2 by cooling gas mixtures to 0 °C under pressure (up to 1.1 MPa). 32 N2 and O2 impurities are concentrated in the gasphase fraction is separated. Both the purified and impurity fractions must be dried, and if used, surfactants must be separated out.…”