Coalbed Methane Produced Water Treatment Using Gas Hydrate

Oak Ridge National Laboratory (ORNL) will assist BC Technologies Ltd, a company based in Laramie, Wyoming, to treat coalbed-methaneproduced water using gas hydrate formation and dissociation. Gas hydrates are solid crystalline compounds of water with gasmolecules, such as methane and carbon dioxide, formed at relatively high pressure and low temperature. Gas hydrate formationexcludes dissolved molecules, ions, and suspended solids from the hydrate structure. Subsequent dissociation of the solid hydrateyields clean water that can be reused for other purposes. The project involves the use of a 72-Liter pressure vessel, the SeafloorProcess Simulator (SPS), available at ORNL. A continuous hydrate reactor will be developed to produce hydrate from gas mixtures andproduced water. The reactor will then be scaled up to process and treat realistic streams of produce water. At the final phase ofthe project, field demonstration of the reactor will be performed. The results are expected to be valuable in efforts toeconomically treat produced water at the wellhead and reuse it for other human activities.