Sodium dodecyl sulfate (SDS) has been reported as the most efficient kinetic promoter for hydrate-based natural gas storage and transportation; however, the foam generation during hydrate dissociation is a serious problem. In this work, we grafted the −SO 3 − group (similar as the hydrophilic group of SDS) on nanosheets of graphene oxide (GO) to prepare −SO 3 −-coated GO nanosheets (sulfonate graphene oxide, SGO), which were then used to promote methane hydrate formation. For comparison, graphene (GP) and GO were also prepared and used as kinetic promoters for methane hydrate formation. Among SGO, GP, and GO, SGO produced the best promotion, which at concentrations of 0.25, 0.5, 0.75 g/L resulted in methane hydrate formation finished within 208.7

ABSTRACT:The fixation of surfactants is very important in surfactant-promoted gas hydrate formation. In this work, three surfactants were fixed on the surface of polystyrene nanospheres through emulsion polymerization (named as Surfactant@PSNS) and then used in methane hydrate formation and dissociation, which were sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and dodecyl alcohol ethoxylates (AEO). The fixation of the surfactants could reduce the induction periods and improve the apparent densities and storage capacities of the formed hydrates, especially at low surfactant concentrations. During hydrate dissociation, the fixation of surfactants resulted in the hydrates dissociating more slowly. The methane recoveries were improved from 76.37%, 27.87%, and 32.35% to 87.55%, 43.43%, and 60.20% for the fixation of SDS, CTAB, and AEO, respectively. Moreover, with surfactants fixed, the foam generation during hydrate dissociation was obviously controlled.