“…For the first factor, some outstanding thermodynamic additives such as tetrahydrofuran (THF) [27], Tetra-b-utyl ammonium/phosphonium salts [17,20,26] and cyclopentane (CP) [28,45] have been proved. For instance, when the simulated landfill gas hydrate formed with 0.0234 mol fraction tetra-n-butyl ammonium bromide (TBAB), the equilibrium hydrate formation pressure could reduce by approximately 90% [17], it is very close to the realistic temperature and pressure condition for separation operating. However, it has been reported that even though the quaternary ammonium salts hydrate could offer greatly enhanced thermal stability, the hydrate formation rate and gas storage capability were very low [21].…”