2-2-3 Investigation of guest ion compositions in semiclathrate hydrates

Abstract

Clathrate hydrates are crystalline compounds comprising cage structures of hydrogen-bonded water molecules with guest molecules. Tetra-n-butylammonium bromide (TBAB) is typical ionic guest molecule that is capable of forming semiclathrate hydrates. TBAB hydrates are stable below 286 K, have relatively high latent heats (190–220 J g^–1), and can entrap small gas molecules such as CO₂ and N₂ under milder conditions; the physical and chemical properties of TBAB hydrates as phase change materials (PCMs) in cold and thermal energy storages are studied by several research groups. In this study, the method for evaluating the compositions in TBAB hydrates was investigated.