BioEd Online

A group of British oil and power companies has announced a plan to tackle carbon emissions. The project will involve removing carbon from natural gas before it is burned, and burying it underground instead of releasing it into the atmosphere.

The scheme, which may begin operation as early as 2009, will make the Peterhead power station in Scotland the world's first 'low-carbon' fossil-fuel-burning plant, the consortium claims.

The plant will take natural methane (CH₄) gas and, through a process involving steam, turn it into hydrogen and carbon dioxide. The hydrogen can then be burned cleanly, producing only water as a by-product. And the carbon dioxide will be pumped out under the North Sea, where it will be deposited in pockets deep underground in the Miller oilfield. The station will aim to remove 90% of the carbon from its gas before burning, hugely reducing emissions.

The project is set to begin its US$20-million engineering phase next year, pending a financial analysis in 2006.

The carbon dioxide will also help to extract the remaining oil from the Miller oilfield. Production at this site, which peaked at 150,000 barrels a day, is now down to 10,000. Adding the gas is expected to increase the pressure underground, which will help in pumping out oil. The development could add 20 years to the field's life, says David Nicholas, a spokesman for BP, which is a member of the consortium.

Hold tight

'Carbon capture' methods provide one way to reduce emissions of the greenhouse gas carbon dioxide into the atmosphere. Up to 50% of the world's carbon dioxide emissions come from power production.

Many analysts advocate the use of nuclear or renewable energy, and say we should reduce power consumption by increasing efficiency. But many are also convinced we must still rely on carbon fuels.

"People will keep having to use coal, oil and gas," says Nicholas. "This is an opportunity to explore how we can reduce their emissions."

Similar schemes for carbon capture exist elsewhere: in one project in the North Sea, carbon dioxide that is already present in natural gas is extracted and buried underground before the methane is burned, which helps to reduce carbon emissions. And BP runs a natural gas field in Algeria where the same thing is done. However, neither of these systems tackles the carbon in the methane.

Dumping grounds

A set of regulations from the OSPAR convention, which protects the environment of the northeast Atlantic, outlaws the dumping of garbage (including carbon dioxide) at sea. But Jon Gibbins, who studies fuel policies at Imperial College London, says that no laws clearly regulate whether carbon dioxide can be stored under the sea floor. And if the gas is pumped underground for a purpose, this means it isn't technically categorized as 'garbage', he notes.

"This project is really a first: the first time carbon dioxide has been taken out of electricity production," Gibbins says. He estimates that the extra cost to the consumer will be a few cents per kilowatt-hour of electricity.

Gibbins adds that the technology of carbon sequestration may prove particularly palatable to countries such as the United States and China, which face a hungry demand for energy and rely heavily on fossil fuels.