Simultaneous mass and heat transfer to/from the edge of a clathrate-hydrate film causing its growth along a water/guest-fluid phase boundary

- Presents analytic model for hydrate-film growth along water/guest-fluid interface.
- Simultaneous mass and heat transfer to/from film front is formulated and solved.
- Methane-hydrate-film growth is found to be rate-controlled by the mass transfer.
- The obtained predictions of film growth are compared to existing observations.

This paper deals with the unidirectional growth of a clathrate-hydrate film along a planar interface between liquid water and a hydrate-guest substance in the gas or liquid state, such as methane gas. The paper first discusses the physical or logical flaws of previous hydrate-film growth models, then describes a new model in which the diffusive mass transfer of the guest substance to the front edge of a hydrate film and the conductive heat transfer from the edge are simultaneously solved to yield a solution for the film growth. The solution procedure is so formulated as to adhere to the balance, on the rate basis, between the film growth relevant to the mass flow of the guest substance to the film-front edge and the heat release from the edge resulting from the exothermic hydrate-crystal formation. The paper finally describes the predictions for the hydrate-film growth along the water/methane interface for comparison with the literature data of relevant experimental observations.