Underground oxidation of hydrocarbons and gas separation yields hydrogen
By Scott Jenkins |
A process for in-situ oxidation of hydrocarbons in low-quality oilfields, and subsequent gas separation, offers a path to generating hydrogen for fuel and chemicals that avoids any greenhouse gas emissions. Known as Hygienic Earth Energy (HEE), the process has been demonstrated at small scale in the western Canada oil sands, and the developing company, Proton Technologies Inc. (Calgary, Alberta; www.proton.energy), is working to scale up the technology in the coming months.
The process works by first injecting oxygen-enhanced air into an underground hydrocarbon reservoir, which would typically be a depleted, late-life or marginally productive oil play. The oxidation processes are initiated by raising the temperature in certain areas of reservoir using steam or other means, but then the reactions continue spontaneously as long as O2 is present within the pore network of the geological substrate that contains the hydrocarbons (sand grains in the case of oil sands).
“Several different oxidation processes are occurring simultaneously underground,” explains Brian Harschnitz, advisor to Proton Technologies. “But the ones that are the most important for hydrogen production are gasification and the water-gas shift reaction.” As the…