Enhancement in Methane Storage Capacity in Gas Hydrates Formed in Hollow Silica

Abstract

Gas hydrate based methodology plays a pivotal role in separation/storage. Some associated crucial issues are optimization of gas content and operational pressure and temperature and developing means of controlled gas liberation upon command and means of converting larger volumes of hydrates rapidly in a lighter (cheaper) medium. Accordingly, we carried out systematic studies, aiming to enhance the methane gas storage capacity in methane hydrates. We used hollow silica to improve the hydrate formation kinetics and efficiency. We observed over 90% hydrate conversion in a silica–water–methane system at moderately high pressure (5.0 MPa) and 278 K. Methane hydrate conversion in such a system is extremely fast, and this material is apt for multiple freezing–thawing cycles without noticeable reduction in the storage capacity. The volume storage capacity increased from 128 to 206 v (STP)/v by decreasing the combined mass of water and silica from 100 and 18 g in a fixed volume nonstirred reactor at pressures higher than 5.0 MPa.