Formation and Dissociation Kinetics of Methane Hydrates in Seawater and Silica Sand

Abstract

Understanding the kinetics of gas hydrate formation and dissociation in porous media has become important since their discovery in permafrost locations and marine sediments. Natural gas hydrates are now recognized as a huge potential source of methane gas. The present work is focused on understanding the kinetics of methane hydrate formation and dissociation in pure water and seawater. Methane gas hydrate formation and dissociation kinetics were studied in Toyoura sand (100–500 μm) with pure water at 8 MPa (driving force of 4.2 MPa) and seawater at 8 and 10 MPa (driving force of 6.2 MPa) and a temperature of 277.15 K. For the present work, 3.03 wt % saline seawater obtained from Pulau Tekong (Singapore) is used. The methane hydrate formation kinetics in Toyoura sand and 100% pure water saturation at 277.2 K and 8.0 MPa was found to agree well with the literature works. For experiments conducted at 277.2 K and a driving force of 4.2 MPa, water conversion to hydrate for the experiments conducted with pure w...