Kinetics of Methane Hydrate Formation from SDS Solution.

The role of sodium dodecyl sulfate (SDS) in methane hydrate formation is investigated in a nonstirred batch reactor. Addition of SDS reduces the induction time, but no systematic trend is observed between induction times and SDS concentrations. The hydrate growth is analyzed by using a diffusion-reaction kinetics model with an assumption that crystallization occurs only in the liquid film at the gas−liquid interface. At the start of hydrate growth, the apparent rate constant increases linearly with increasing aqueous SDS concentrations. The apparent rate constant during hydrate growth increases as more available gas−liquid interface is generated. SDS not only increases hydrate nucleation rate by reducing the interfacial tension between hydrate and liquid but also accelerates hydrate growth rate by increasing the total surface area of hydrate particles and the gas−liquid interfacial area. [ABSTRACT FROM AUTHOR]