Synthesis of anionic multichain type surfactant and its effect on methane gas hydrate formation

This paper reports an experimental study on the effects of novel anionic multichain disulfonate surfactant on the formation of methane gas hydrate. A series of surfactants with sodium sulfonic acid groups and different hydrophobic carbon chain lengths (C8, C10, and C12) were synthesized, and the effects of carbon chain length and concentration on methane hydrate formation kinetics were systematically investigated. Methane hydrate formation was conducted in a magnetic stirred vessel at the constant temperature of 274.15 K and in a pressure range of 3.5–4.0 MPa. All surfactants showed kinetic promoting behavior for methane gas hydrate formation, and the surfactant with the shortest chain length showed the highest acceleration effect. In addition, this multichain disulfonate surfactant exhibited higher methane storage capacity than SDS (sodium dodecyl sulfate) even at lower surfactant concentration, due to its lower critical micelle concentration (CMC) and the surface tension itself of the Gemini-type multichain surfactant.