Phase Equilibria for H₂ + CO₂ + Tetrahydrofuran + Water Mixtures Containing Gas Hydrates

Abstract

Isothermal phase equilibria (pressure−composition in the gas phase) for the quaternary system of H 2 + CO 2 + tetrahydrofuran + water have been measured in the presence of gas hydrate phase. The lowest three-phase equilibrium pressure is obtained under the condition that the mole fraction of tetrahydrofuran in water is 0.056. The Raman spectroscopy results show that the H 2 and CO 2 molecules competitively occupy the S-cage of structure-II (i.e., the H 2 molecule is enclathrated in the hydrate cages with a small amount of tetrahydrofuran at considerably low pressure).