The experiment was designed to use isothermal depression method to research the dissociation kinetics of methane hydrate in active carbon. Five groups of kinetic data (P ～ t) of methane hydrate dissociation in active carbon were obtained in the temperature range of 276 ～ 265 K and at the initial dissociation pressure of 0.1 MPa. A three-phase (gas-water-hydrate) depressurization kinetic model was developed for hydrate dissociation in active carbon in which a key concept of "porous plate" was proposed. It is assumed that the diffusion of methane in the porous plate is the control step in the process of hydrate dissociation when the temperature is below ice point. The numerical solution of this model is obtained by Gear single-step extrapolation method. THe simplex optimization method is used to fit the model parameters. The model provideds a satisfactory fitting to the experimental data. According to the experimental data, the active energy of dissociation reaction of methane hydrate is E = 89.8 kJ· mol~(-1) in the temperature range of 273 ～ 265 K.

Key words: METHANE, HYDRATE, ACTIVE CARBON, KINETIC STUDY, DECOMPOSITION