Studies on hydrate film growth

Abstract

The hydrate film properties and growth law at the interface between water phase and hydrate former (guest) phase are of significance to the overall study of hydrate formation kinetics and for developing methods to promote or inhibit the hydrate formation with respect to different industrial applications. In recent years, the experimental tools have become available to qualitatively observe the morphological nature of the film and quantitatively measure the growth of hydrate film. In this review, we provide an overview of the current state-of-the-art in the observation of hydrate film morphology, measurement and modeling of hydrate film growth rate. First, we review the morphological observations of hydrate formation at hydrate former/water interfaces occurring in different cases, such as bulk hydrate former phase contacting bulk water phase, small hydrate former droplets being exposed to bulk water phase, small water droplets being exposed to bulk hydrate former phase, and gas bubbles being suspended in bulk water phase. In the second section, the experimental determination of the lateral growth rate along the guest/water interface, the vertical growth rate normal to the guest/water interface and thickness of hydrate film are summarized. The mechanism and modeling of lateral growth and vertical growth of hydrate film are reviewed in the third section.