Equilibrium of Ethane Hydrate Formation in Carbon Pores

Abstract

The formation of hydrates in carbon pores was utilized to store natural gas, and ethane is the second major component of natural gas; therefore, ethane hydrate formation in carbon pores is studied in comparison with that of methane. Ethane is a major raw material of ethylene in the petrochemical industry; therefore, its mixture with ethylene is of importance and the formation condition of ethane hydrates was compared also with that of ethylene. The equilibrium isotherms of ethane on wet carbons with different water contents as well as the isotherms for different temperatures were collected, from which the formation pressures of ethane hydrates as well as the enthalpy change of ethane hydrate formation were determined. It was shown that the largest volumetric capacity for ethane storage is observed at the water load that just about fully fills pore spaces. Ethane hydrates were formed in wet activated carbons at about same pressures as in water media and the formation pressure is much lower than that required for methane hydrates formation.