Effect of spraying and stirring on the formation and decomposition of CH4 hydrates in the presence of copper foam and 1,3-DIOX

Abstract Gas hydrates are considered as a safe and efficient method for gas storage and transportation. However, slow formation rate and limited storage capacity hinder the industrial application of this technology. In order to accelerate CH₄ hydrates formation and enhance CH₄ capacity, spraying and stirring method were applied on the kinetic formation of CH₄ hydrates in the presence of copper foam (CF) and 5.56 mol% 1,3-dioxolane (1,3-DIOX) under 2.0 MPa to 4.0 MPa. The results show that adding 1,3-DIOX not only can shorten the induction times but also increase the gas consumption, and the CF materials also had a positive effect on the kinetics of CH₄ hydrates formation. The 60PPI CF + 1,3-DIOX performed the best on the induction times of only 12.45 min, being reduced by 66.8% compared with that without CF. Comparing to the pure water, 60PPI CF single system and the 1,3-DIOX single system, the 60PPI CF + 1,3-DIOX exhibited the highest gas consumption of 0.1733 mol/molH₂O, increased by 261.04%, 136.75% and 74%, respectively. Furthermore, based on programmed heating, the decomposition process of CH₄ hydrates was investigated. The results show that the CH₄ hydrates formed by the spraying method decompose more easily during the heating process, while the CH₄ hydrates formed by the stirring method has the highest stability. Moreover, the CH₄ hydrates formed in CF + 1.3-DIOX system can exert a self-preservation effect during the early stage of decomposition and inhibit the initial decomposition of CH₄ hydrates to some extent. These results provide a reference for the practical application of hydrate solid-phase safe storage and transportation of gases.