Natural gas is an abundant and widely used in many major sectors, but the transport and storage of this fuel poses challenges. Current methods entail chilling of natural gases to exceedingly low temperatures (-162° C) to form liquefied natural gas (LNG), which is not suitable for long-term storage. Researchers are turning to the development of solidified natural gas (SNG), or natural gas hydrates, as a promising storage solution.

With appropriate additives and defined pressure-temperature conditions, the containment of gases inside cages formed by water molecules yield a stable, solid material that is suitable for long-term storage and can be transported without the dangers inherent with pressurized flammable liquids. A non-volatile promoter to support SNG formation has been identified as an alternative to the corrosive and toxic agents commonly tested.

Researchers investigated 1,3-dioxane (dioxane), a low-toxicity chemical additive, for the formation of a mixed methane hydrate at room temperature. The average methane storage capacity achieved was 135.13 v/v, surpassing the established limit of 115 v/v for this type of methane hydrate. A mixed methane/dioxane hydrate pellet, stored in a tightly sealed container under near atmospheric pressure and a moderate average temperature of 268.3 K for 120 days, was demonstrated to maintain excellent stability throughout the duration of storage.

The study conducted by researchers from the National University of Singapore, China Jiliang University, Dalian University of Technology (China) and Indian Institute of Technology Madras offers potential for an energy dense SNG form with significant commercialization potential. The research is published in the journal Energy & Environmental Science.