Sub Sea Methane Hydrates

Introduction

• Methane hydrates are being evaluated as a potential fuel for the future. Some believe there is enough methane in the form of hydrates—methane locked in ice—to supply energy for hundreds, maybe thousands, of years.
• Methane hydrates are 3D ice-lattice structures with natural gas locked inside, and are found both onshore and offshore – including under the Arctic permafrost and in ocean sediments along nearly every continental shelf in the world. Gas hydrates are clathrate compounds. A clathrate is simply a structure in which water molecules under certain conditions bond to form an ice-like cage that encapsulates a gas molecule, known as a guest molecule. When that guest is a methane molecule, you have methane hydrate.
• The substance looks remarkably like white ice, but it does not behave like ice. When methane hydrate is "melted," or exposed to pressure and temperature conditions outside those where it is stable, the solid crystalline lattice turns to liquid water, and the enclosed methane molecules are released as gas.

Links

• Oak Ridge National Laboratory

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