Effect of Sodium Dodecyl Sulfate on the Supercooling Point of Ice and Clathrate Hydrates

Abstract

The effect of sodium dodecyl sulfate (SDS) on the supercooling point (SCP) of ice, tetrahydrofuran (THF) hydrates, and THF + CH(4) binary hydrates was investigated by using a high-pressure differential scanning calorimeter (DSC). At a nominal SDS concentration range of 0-500 ppm, no specific trend was observed between the SDS concentration and the SCP of ice and the clathrate hydrates. The SCP of ice, THF hydrates, and THF + CH(4) hydrates with a THF concentration of 20 wt % and at a methane pressure of 7.14 MPa varies from 260.4 to 262.8 K, 252.8 to 254.7 K, and 268 to 269.5 K, respectively, at SDS concentrations below 500 ppm. The minor variation of the SCP subject to the different SDS concentrations implies that the SDS does not significantly influence the heterogeneous hydrate nucleation but it most likely accelerates the hydrate growth.