FORMATION OF A HYDRATE LAYER AT A GAS–WATER (ICE) INTERFACE

The problem on the formation of a hydrate layer in a spherical particle with an ice core and on the surface of a gas bubble coming to the surface of a water was solved numerically. As a limiting scheme of hydrate formation in these cases, the diffusion mechanism, implying the diffusion of a gas (water) in the hydrate layer formed at the contact line between a gas and an ice or a water to the surface of contact of the hydrate with the ice, the water, or the gas, was adopted. A comparative analysis of the results of numerical calculations of the formation of a hydrate layer in the indicated cases with the corresponding experimental data made it possible to estimate the reduced coeffi cients of diffusion of a gas and water in such a hydrate layer. It is shown that the model of hydrate formation comprising kinetic relations, obtained as a result of the solution of a quasi-stationary diffusion equation, allows one to defi ne the transformation of a water or a gas into the hydrate state with the use of a single empirical parameter having the dimensions of the diffusion coeffi cient. The qualitative and quantitative patterns of the formation of a hydrate particle, obtained with the use of the indicated kinetic relations, agree with the corresponding experimental data and theoretical calculations of other researchers, and by them, a large number of empirical parameters, which are not known in advance but should be determined, can be estimated.
   
Author:  A. S. Chiglintseva and A. A. Rusinov
Keywords:  hydrate layer, gas bubble, ice particle, reduced diffusion coeffi cient
Page:  1396