Formation and agglomeration of gas hydrates in gas – organic liquid – water systems in a stirred reactor: Role of resins/asphaltenes/surfactants

Abstract In the present work, the nucleation and growth of methane hydrate and C 1 C 3 mixed hydrate in the systems with organic liquids ( n -decane, toluene, crude oils) have been studied. The experiments were carried out in an autoclave at a stirring rate in a range of 100–600 rpm and at a constant cooling rate of 8.4 °C/h under isochoric conditions. In the case of n -decane, the experiments were conducted both with the addition of 0.5 wt % of non-ionic surfactants (Span 80 or Surfynol 420) and without them; in the case of toluene the experiments were performed with addition of natural resins and asphaltenes. It was shown that Surfynol 420 had the lowest anti-agglomeration activity with respect to hydrate particles in comparison with Span 80 and oils used. Gas hydrate nucleation occurred at a lower degree of supercooling in the case of oils with a higher content of resins and asphaltenes. The change of resistance to flow in the obtained disperse systems had a reverse trend. Based on the obtained data it can be concluded that the unambiguous effect of the stirring rate on the hydrate nucleation in systems with different composition is not observed. At the same time, an increase in the stirring rate leads to an increase in the amount of gas hydrate formed in a system.