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.