Abstract:

The formation of methane hydrate from a mixed system of ice powders（154—300 μm）and sand（154—300 μm）was studied at 6.9 MPa and different temperatures.Its formation mechanism was also analyzed, and thereafter a kinetic model was proposed.The results showed that the hydration rate of ice powders (α) decreased with temperature and was 65% at 273 K, 51% at 269 K, and 42% at 263 K.The formation process could be divided into two stages,absorption and transfer stage,diffusion-control stage.The activation energy estimated from these data was 70.1 kJ·mol^-1.