ABSTRACT

The equilibrium conditions were experimentally determined for gas hydrate of methane and ethane mixtures in pure water and 3.0 wt% NaCl solution. The present results indicate that the addition of ethane stabilizes gas hydrate and shifts the equilibrium conditions to higher temperature and lower pressure. As ethane concentration increases from 0 vol% to 10 vol%, the equilibrium pressure of gas hydrate decreases non-proportionally with gas composition, which implies a change in the hydrate structure over this range of gas composition. The equilibrium temperature of gas hydrates of methane and ethane mixtures in 3.0 wt% NaCl solution is approximately 1.0 K lower than that in pure water at a constant pressure.