Synthesis of methane gas hydrate in porous sediments and its dissociation by depressurizing

The clathrate compounds of methane gas hydrate (MGH) was synthesized in laboratory at a temperature of 273.5 K and at a pressure of 6.8-13.6 MPa, consisting of solid phase MGH dispersed within various custom-designed porous sediments. This synthesized MGH looks almost like the MGH made by Mother Nature in the strata in the natural gas hydrate (NGH) field. Using this synthesized MGH, the dissociation rate was measured by depressurizing method. From experimental results, the kinetic dissociation rate equation and order of the reaction were derived. It was found through experiments that the dissociation rate could be adjusted by the control of sediment properties. With respect to MGH formation reaction, the reaction rate equation and its reaction order were also derived. (C) 2002 Elsevier Science B.V. All rights reserved.