Dissociation of gas hydrate for a single particle and for a thick layer of particles: The effect of self-preservation on the dissociation kinetics of the gas hydrate layer

Abstract

To date, prediction of the dissociation of single gas hydrate particles at positive temperatures is found to be effective. Meanwhile, there are no reliable approaches that would allow modeling the dissociation at negative temperatures, taking into account the heat flux, the thickness of the powder layer, as well as the diameter of the cylinder or tablet, consisting of small particles. These studies are relevant for the development of technologies for storing and transporting methane hydrate. This paper deals with modeling the dissociation of the methane hydrate, taking into account the temperature in the self-preservation region, and considers the influence of four characteristic scales: the layer thickness (or the cylinder diameter), the average diameter of a single particle, the average pore diameter in a particle, and the porosity in a layer or in a consolidated sample. Experimental and theoretical studies of dissociation in a wide temperature range are carried out. It is shown that for efficient storage of methane hydrate, the most optimal conditions correspond to the packing of small particles in a cylinder, tablet or thick layer. The ways of reducing the dissociation rate due to the multilevel consolidation of particles in a large sample are proposed. The results obtained may be useful for improving the efficiency of storage and transportation of gas hydrates at negative temperatures.