Micromechanical Interactions between Clathrate Hydrate Particles and Water Droplets: Experiment and Modeling

The micromechanical interactions between hydrate particles and unconverted water droplets play an important role in determining hydrate agglomeration, which is a key cause of hydrate blockages. In this study, the interaction behaviors between cyclopentane hydrate particles and water droplets in different conditions were directly investigated using a micromechanical force apparatus. For a smaller extent of subcooling, no hydrate was visibly converted from the water droplet during the measurement. A modified theoretical model was proposed to predict the corresponding interaction behavior. A parabolic approximation was found to be adequate for describing the liquid bridge shape. The insignificant change in the interfacial area between the liquid and the hydrate as the separation distance varied suggests the presence of a strong wetting hysteresis between liquid bridges and hydrate particles. The capillary force model can predict the interaction forte with satisfactory accuracy. At a higher level of subcooling, the amount of hydrate converted from water droplets during the interaction led to a reduction in liquid volume and to dynamic changes in the boundary. The theoretical model presented here is not adequate for this specific case. Furthermore, a lower temperature induces more hydrate formation during measurement, which can increase the adhesion force. Compared with cohesion forces between a hydrate particle and a particle, adhesion forces between a hydrate particle and a droplet should dominate hydrate agglomeration. The present experiment and modeling contributes an improvement to the current understanding of hydrate agglomeration, leading to new potential strategies to control this process.