Effect of heat transfer on the kinetics of methane hydrate dissociation

The dissociation of methane hydrate under external pressure of 1 bar is studied experimentally. Non-isothermal dissociation is fundamentally different from the quasi-isothermal case. The increase in the density of heat flux from 255 to 13700W m(-2) results in 9-fold increase in the dissociation rate of methane hydrate. Different variations of clathrates dissociation may be observed depending on the heat flux magnitude: (1) without self-preservation (high heat fluxes), (2) a partial self-preservation with one minimum of dissociation rate, and (3) a partial self-preservation with two minimums (low heat fluxes). When describing dissociation kinetics of the spherical granules, it is important to know the time dependence of the ice layer thickness growth. It is shown that not the curvature, but the heat flux value regulates the dissociation rate and the change in diffusion. A drastic change in dissociation rate is caused by a pressure decrease in pores. (C) 2013 Elsevier B. V. All rights reserved.