Estimation of the Formation Rate Constant of Methane Hydrate in Porous Media

Abstract

Summary Hydrate formation and the relevant mass and heat transfers were numerically analyzed in a microscopic computational domain in which spherical glass beads, water, and methane gas were distributed separately. A hydrate-formation experiment was also carried out by use of a cylindrical pressure cell. The temperature in the cell was controlled by Peltier devices, which were attached to the outer walls of the cell to imitate the adiabatic boundary condition present in the numerical simulation. By history matching between the experiment and calculation, we first obtained a hydrate-formation rate constant per unit volume of water, assuming homogeneous nucleation. Then, after converting the rate by use of a surface-area model of water in porous media, we noted that the area-based rate constant and activation energy of the hydrate formation were estimated to be 6.33 × 1034 mol·m–2 Pa–1 s–1 and 238 × 103 J/mol, respectively, for temperatures of 1.5 to 3.4°C.