Methane gas hydrate kinetics with mixtures of sodium dodecyl sulphate and tetrabutylammonium bromide

• Published in: The Canadian Journal of Chemical Engineering
• Main Authors: Renault‐Crispo, Jean‐Sébastien, Servio, Phillip
• Other Authors: Natural Sciences and Engineering Research Council of Canada
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2018
• Subjects: Methane hydrate
• Online Access: http://dx.doi.org/10.1002/cjce.23094; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fcjce.23094; https://onlinelibrary.wiley.com/doi/pdf/10.1002/cjce.23094

The effect of combining a thermodynamic promoter, tetrabutylammonium bromide (TBAB), with a kinetic promoter, sodium dodecyl sulphate (SDS), to a methane clathrate system was investigated. Kinetic growth experiments were conducted in a semi‐batch stirred tank crystallizer at driving forces of 1500 kPa using a range of 100 to 1500 ppm SDS and 200 to 200 000 ppm TBAB. Solutions containing low concentrations of TBAB in water reduced methane hydrate growth rates up to 55 % for 1250 ppm TBAB compared to pure water. Solutions containing 900 ppm SDS in water enhanced the growth rate by 880 % compared to pure water. Solutions were then tested combining both promoters. The gradual addition of SDS from concentrations between 100 to 1250 ppm to low‐concentration TBAB systems between 200 to 1250 ppm was initially found to reduce growth kinetics, but eventually increased the growth rates once a threshold SDS concentration was reached. In all cases, the promoting effect of the SDS was more pronounced in the absence of the TBAB. The growth kinetics of systems containing 5 and 20 wt% TBAB also followed a similar inhibition‐promotion trend with the SDS concentration. An increase of 177 % in the gas consumption rate was observed when 1500 ppm SDS was added to the 20 wt% TBAB clathrate system. This work demonstrates that SDS can be added to a TBAB‐water‐methane system to enhance gas consumption rates, but care must be taken to ensure that the concentration of the additives places the system in a promotion regime.