The effect of hydrate promoter SDS on methane dissolution rates at the three phase (H-Lw-V) equilibrium condition

摘要

Clathrate hydrate promotion research has often focused on hydrate growth rate differentiation, however little work has been done to understand the kinetics of dissolution. The dissolution of gas into the bulk liquid phase is of great importance to hydrate growth, as it is the first step in hydrate formation. Furthermore, understanding the influence of additives on hydrate systems may provide significant insight into the mechanisms of their function. The effect of the hydrate promoter sodium dodecyl sulphate (SDS) on methane dissolution was thus investigated at the three-phase (H-Lw-V) equilibrium condition of 275.1 K and 3145 kPa. Experiments with concentrations of SDS ranging from 0.01 mM to 4 mM were conducted. The purpose of this study was to investigate the effects on the methane equilibrium saturation values as well as the kinetics of dissolution. The effects on saturation were found to be negligible. The rate of dissolution was measured using a first-order response model and the time constant tau (tau). It was found that the values of tau for SDS increased with an increasing loading of 0.01 mM -0.75 mM and then plateaued for concentrations ranging between 0.75 and 4 mM producing a sigmoidal trend. (C) 2016 Elsevier B.V. All rights reserved.