Cooperative effect of surfactant addition and gas-inducing agitation on methane hydrate formation rate

•A combined mechanical and chemical method was used to promote hydrate formation.•This method comprises surfactant addition and gas-inducing agitation.•This method led to increased hydrate formation rate. This paper reports experimental measurements of the isothermal and isochoric formation kinetics of methane hydrate in sodium dodecyl sulphate (SDS) solutions of various concentrations with gas-inducing agitation, and the results are compared with those obtained with normal agitation and no agitation. The experiments were conducted at 274 K with initial gas pressure of 10 MPa. At a given SDS concentration, the gas-inducing agitation gave higher hydrate formation rate than normal agitation and no agitation. Gas inducing agitation of deionized water gave a relatively low methane hydrate formation rate, which could be greatly enhanced by adding SDS. The enhanced kinetics can be attributed to increased gas-liquid contact area, with the coalescence of induced gas bubbles being effectively inhibited by SDS at low concentrations.