Mining - Biodegradation of oil sands into methane

An idea founded long ago is on the rise again. Scientists said recently in the journal Nature they can radically speed up the underground bacterial fermentation that turns Canada's tar-like Athabasca sands into natural gas at far less cost and with far less environmental pollution.

This is huge global news because the world has about 6 trillion barrels of such heavy oil, more than 20 times the proven oil reserves in Saudi Arabia. They're focused in Canada's Athabasca, in Venezuela's Orinoco tar belt, and in the oil shale of the U.S. Rocky Mountains. All may be economically recoverable with bacterial refining.

Dr. Steve Larter of the University of Calgary says understanding how anaerobic bacteria ferment heavy oil into clean-burning methane underground opens the door to recovering the gas from deeply buried oil sands.

"The main thing is you'd be recovering a much cleaner fuel," he says. "Methane is, per energy unit, a much lower carbon dioxide emitter than bitumen."

A separate family of microbes that produces CO2 and hydrogen from partly degraded oil offers a way to capture the CO2 from the tar sands as methane, for burning in a closed-loop system would keep the CO2 out of the atmosphere.