Clathrate formation in water-peralkylonium salts systems

Experimental measurement and thermodynamic modelling of hydrate phase equilibrium conditions for krypton + n -butyl ammonium bromide aqueous solution

“…This strong hydrogen bonding leads to a more stable semi-clathrate hydrate structure compared to the conventional clathrate hydrate structure [40]. Crystals with type A have been described to have a columnar (tetragonal) shape with a higher hydrate equilibrium temperature compared to type B which have an undefined (orthorhombic) form composed of thin crystals [36,42].…”

“…Tetra-n-butyl ammonium bromide (TBAB), tetra-n-butyl ammonium chloride (TBAC), tetra-n-butyl ammonium fluoride (TBAF), and tetra-n-butyl phosphonium bromide (TBPB) are quaternary ammonium salts which were discovered by Fowler et al in 1940 [34]. As QAS promoters can form semiclathrate hydrate crystals (with or without any guest molecule) at low pressures close to atmospheric pressure [35,36], these additives can be used in processes such as storage and transportation of natural gas, gas separation, and cold storage applications in air conditioning systems [37,38]. In the semi-clathrate structure, the positive/cation portion of the QAS can be placed at the centre of the cavities which are made by water molecules and the negative/ anion portion of the QAS using hydrogen bonding [39][40][41].…”

Separation and capture of carbon dioxide from CO2/H2 syngas mixture using semi-clathrate hydrates

“…at 1 atm and 12 • C (Jeffrey and McMullan, 1967;Dyadin and Udachin, 1984;Oyama et al, 2005). If a gas or mixture of gases is associated with these hydrates, the thermodynamic stability of the mixture becomes even more favourable (Hashimoto et al, 2006;Arjmandi et al, 2007;Li et al, 2007).…”

Clathrate Hydrates for Thermal Energy Storage in Buildings: Overview of Proper Hydrate-Forming Compounds

“…Furthermore, TBAB, TBAC and THF are characterized by rapid hydrate formation [40][41][42][43][44][45][46][47]. TBAC hydrates have a melting point of 15.0 °C and a latent heat of 200.7 kJ/kg [44,45], while THF hydrates have a melting point of 4.4 °C and a latent heat of 260 kJ/kg [46,47].…”

“…TBAC hydrates have a melting point of 15.0 °C and a latent heat of 200.7 kJ/kg [44,45], while THF hydrates have a melting point of 4.4 °C and a latent heat of 260 kJ/kg [46,47].…”