Theoretical investigation of storage capacity of hydrocarbon gas in sH hydrate

Abstract

Hydrates are considered an excellent approach for transporting and storing natural gas. In this study, the structural properties and stability of sH hydrates with the inclusion of different hydrocarbon molecules were investigated by performing density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations. The small and medium cages can encapsulate one methane molecule per cage. The large cage is likely to encapsulate the long straight-chain hydrocarbon molecules than the small hydrocarbon molecules, and the optimum cage occupancy is four methane molecules, three ethane molecules, two propane molecules, two butane molecules, and one pentane molecule, respectively. The presented results provide a much needed molecular insights of sH hydrates and are helpful to promote the development of the hydrate technology for the storage and transport of natural gas.