The effect of powder aggregates, carbon nanotubes and surfactants on the kinetics of synthesis and dissociation of gas hydrates

Hydrate clusters are a viable option for the transportation of associated petroleum gas, which is much cheaper than natural gas. However, gas hydrate synthesis and dissociation take a long time. In this research, experiments were performed with carbon nanotubes (CN) and surfactants added to reduce the synthesis and dissociation time. Dependencies and optimal conditions for the sizes of hydrate powder aggregates, at which the maximum reaction rate is achieved, have been determined. An increased rate of growth of gas hydrate crystals is achieved at a nanotube concentration of 0.1–5 wt%. It was established that the minimum size of the aggregates, the addition of nanotubes and surfactants reduced the gas hydrate synthesis and dissociation times. The combined use of CN and SDS reduced the synthesis time by 60 % and the dissociation time by 20 %. The most significant influence of the size of the aggregates is achieved at a high rate of decomposition. The minimum average aggregate size of the methane hydrate powder corresponds to a nanotube concentration of 0.1 wt%. A technological concept has been developed for transporting associated petroleum gas in the form of gas hydrate with an efficiency of at least 90 %.