Gas-liquid asynchronous cooling promoting gas hydrate formation with high energy efficiency and its promoting mechanism

Hydrate technology has a bright future in the development of high quality production and life for human being. However, the slow hydrate formation rate and low gas consumption are the biggest two obstacles to the commercial application of the technology. In this study, the macro experimental investigation, simulation calculation and microscopic analysis are combined to study the process of the hydrate formation and the effects of gas molecules at different cooling ways on the hydrate nucleation process from the perspective of the transformation of free-water to bound-water. Macroscopically, the difference of gas–liquid temperature makes the heat transfer process between gas and liquid at the interface more active, which is more conducive to the diffusion of gas to liquid; and microscopically, the transformation of free-water to bound-water and the distance between oxygen atoms d OO $\left(d_{\mathit{OO}}\right)$ of adjacent water molecules in the hydrate nucleation are the two key factors affecting the rate of hydrate formation and gas consumption. The results of this study not only propose a more efficient hydrate formation way, but also provide direction for solving the key bottleneck of hydrate technology so that it possible for the hydrate technology from laboratory research to industrial application.