Direct Observation of the Effect of Sodium Dodecyl Sulfate (SDS) on the Gas Hydrate Formation Process in a Static Mixer

摘要

Direct observation and the measurement of the formation rate of the gas hydrate of HCFC-22 in a Kenics-type static mixer were conducted in a laboratory-scale experimental apparatus. This study focused on the effect of sodium dodecyl sulfate (SDS) addition on the hydrate formation process under the SDS concentration below the critical micelle concentration (cmc). The hydrate film was formed at the surface of bubbles in any case, but the appearance of the hydrate film and its behavior were significantly changed with increasing the SDS concentration. Without SDS, smooth and homogeneous hydrate film was formed at the surface of HCHC-22 bubbles. The HCFC-22 gas was trapped in the shell of the rigid hydrate film, and the bubbles agglomerated each other to form a grape-like structure. From the addition of SDS, the hydrate film formed with a rougher and heterogeneous surface; the hydrate film seems to have a loose structure and easily collapsed from the buoyant motion of the HCFC-22 gas trapped in the shell. The enhancement of the gas hydrate formation by the SDS addition can be attributed to the mass transfer through the loose hydrate film and the surface renewal by the film collapse.