Study on the influence of driving force on growth kinetics of CH4 hydrate in coal medium

Abstract

Coal and gas outburst is one of the most serious kinetic disasters in coal mines, and the use of gas hydrate curing technology to reduce the gas pressure and its gradient in the coal body can reduce the probability of coal and gas outburst accidents. In order to investigate the influence of driving force on the growth kinetics of CH4 hydrate in coal medium, the experimental study on the growth kinetics of gas hydrate in coal medium under three driving force conditions was carried out by using the experimental system of gas hydrate growth kinetics, and the influence of the driving force on the parameters such as gas consumption and growth rate during the synthesis process of gas hydrate in coal medium was discussed. The results show that: within the same particle size range, the nucleation time of hydrate in each particle size range does not completely follow the law of subsequent shortening when the driving force is increased, and the nucleation of CH4 hydrate in coal medium has a certain degree of randomness; the phenomenon of multiple nucleation occurs in the synthesis process; the gas consumption of CH4 hydrate in the coal medium increases with the increase of the driving force; the growth rate of gas hydrate in coal medium is increased with the increase of the driving force, and the growth rate of gas hydrate in coal medium is improved with the increase of driving force under the condition of unchanged temperature and particle size. The effect of driving force on the average growth rate at the early stage of synthesis is more significant.

Keywords

• coal and gas outburst
• hydrate
• driving force
• gas consumption
• growth rate