Electric resonance-induced hydrate dissociation acceleration to extract methane gas

Methane extraction from natural gas hydrates has been a great challenge owing to the slow decomposition kinetics. Here, combining molecular dynamics simulation with density functional theory calculations, we propose a strategy to accelerate the hydrate dissociation to release methane rapidly based on an analysis of the vibration modes of the sI methane hydrate and a rational selection of the electric field. It is observed that the hydrate dissociation is significantly affected by the applied oscillating electric field, with the greatest degree of hydrates decomposition and the largest gas release occurring at the electric fields that have the frequency f and the amplitude A of f = 1810 GHz and A beyond 0.18 v/angstrom, f = 8550 GHz and A beyond 0.11 v/angstrom, or f = 18500 GHz and A = 0.1 v/angstrom, respectively. The maximum amount of methane extraction ascribes to the electric resonance induced by the oscillating electric field with frequency equal to the inherent resonance frequency of the hydrate. The electric resonance results in the breakage of hydrogen-bonded networks inside the hydrate, thereby improving the hydrate dissociation and releasing methane. The new mechanism of regulating hydrate decomposition revealed in this work provides an insight into methane exploitation from natural gas hydrate reservoirs and has promising applications in the design of gas hydrate-based technologies.