Methane Hydrate Formation Promoted by -SO3--coated Graphene Oxide Nanosheets

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 -SO3- group (similar as the hydrophilic group of SDS) on nanosheets of graphene oxide (GO) to prepare -SO3--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 +/- 26.6, 242.3 +/- 97.6, and 312 +/- 135.5 min, respectively, with storage capacities reaching 139.7 +/- 4.7, 143.3 +/- 6.1, and 143.9 +/- 7.2 v/v, respectively. Furthermore, -SO3--coated nanosheets of SGO even produced better promotion to methane hydrate formation compared with SDS and avoided foam generation during hydrate dissociation, which has great: potential in hydrate-based natural gas storage and transportation.