Effects of Nanofluids and Surfactants on the Formation Kinetics and Gas Storage Capacity of Methane Hydrates

A high-pressure reactor was used to study the impact of nanofluid-based composite surfactants on the process of the formation of methane hydrates at 5 degrees C (278.15 K) and 870 psi (6 MPa). Nanofluids, known for their large specific surface areas and efficient heat transfer properties, when combined with anionic surfactants, perform well when subjected to the conditions of hydrate kinetics experiments. They considerably reduce the hydrate induction time, promote kinetic growth, and enhance the extent of gas consumption realized. An organosilicon defoamer was introduced into the compound system (in the case of using sodium dodecyl sulfate) to address foam-related issues encountered during hydrate formation. The results reveal that sodium dodecyl sulfate and graphene oxide can significantly improve the kinetic parameters that characterize methane hydrates. The optimal conditions were identified, and 0.2 g/L graphene oxide +500 ppm sodium dodecyl sulfate was the optimal choice. Under the specified concentration conditions, the gas consumption was measured to be 0.152 mol, and the effective gas storage capacity reached 176.74 V/V. It is worth noting that this effective gas storage capacity was 3 times higher than that recorded in pure water. The gas storage capacity of the sodium dodecyl sulfate-graphene oxide system increased by 227% compared with the pure water system, and the generation time was nearly 60% shorter than that of the pure water system. The foam could be effectively eliminated using 0.1% of the defoamer, and the amount of hydrate generated under these conditions was 97% of the amount of sodium dodecyl sulfate hydrate. This study explores the effects of different systems on hydrate kinetics and can achieve excellent defoaming effects and better hydrate production capacity in systems with defoamers, which is beneficial for the application of graphene oxide and sodium dodecyl sulfate in natural gas hydrate technology and has important industrial value.