CLATHRATE HYDRATE PHASE EQUILIBRIA FOR CARBONYL SULFIDE, HYDROGEN SULFIDE, ETHYLENE, OR PROPANE + WATER SYSTEM BELOW WATER FREEZING POINT

Abstract

Presented are ice-clathrate hydrate-vapor equilibrium data (dissociation data) for the carbonyl sulfide, hydrogen sulfide, ethylene, or propane + water system in the temperature ranges of 243.5–271.0 K. The equilibrium data for the carbonyl sulfide or ethylene + water system were generated using an isothermal pressure-search method, while an isochoric pressure-search method was used to carry out the measurements for the hydrogen sulfide or propane + water system. The new equilibrium data for propane clathrate hydrates are compared with the equilibrium data reported in the literature to demonstrate the reliability of the isochoric pressure-search method (the reliability of the isothermal pressure-search method has already been demonstrated by the authors). The equilibrium data generated for hydrogen sulfide and ethylene simple clathrate hydrates are compared with a few sets of experimental data reported in the literature. It is found that such data for the latter clathrate hydrates are indeed scarce. Finally, the ice-clathrate hydrate-vapor equilibrium conditions of the clathrate hydrates of carbonyl sulfide, hydrogen sulfide, ethylene, and propane are compared.