Study on the kinetic characteristics of gas hydrate in the dioctyl sodium sulfosuccinate system.

Abstract

Surfactants promote the production of hydrates, which provide a possibility for the industrialization of hydrate technology. In this paper, methane and CO2 hydrate formation experiments were carried out, respectively, with surfactant-dioctyl sodium sulfosuccinate (DSS) using a visual experimental apparatus at a constant pressure. This study explored the influence of the surfactant dosage, experimental pressure, and subcooling temperature on the dynamic characteristics of hydrate formation. The results indicated that a small amount of surfactant had a significant promotion effect on the formation of hydrate, i.e., 600 mg L−1 DSS shortened the induction time of methane hydrate by 60 times and that of CO2 hydrate by 2.4 times, while it increased the formation rate by 3.4 times. Due to the weak acidity of the CO2 solution, the effect of DSS on CO2 hydrate formation was significantly reduced. The DSS concentration had a limited effect on changing the rate of the gas storage capacity of the two hydrates. Compared with other surfactants reported in the literature, DSS showed a better promotion effect on hydrate formation. This study reveals the mechanisms of interfacial tension reduction and the promotion of hydrate growth adhering to the wall using a surfactant with a double-chain structure, which further enriched the hydrate-promoting mechanism, and provides experimental data and a theoretical research basis for the study of kinetic characteristics of hydrates in surfactant systems.