DOE, congress to spur carbon sequestration

Even as the US Department of Energy announced the awarding of a fourth grant for assessing the commercial-scale underground sequestration of carbon dioxide, President Bush’s science adviser was expressing doubts that efforts to bottle up the greenhouse gas will mitigate global warming.

“We do not currently have a scalable technology for carbon sequestration, and I do not see one coming soon,” John Marburger told a meeting of the American Geophysical Union in December 2007. The world’s “stunningly large fossil-fuel consumption numbers” and the roughly 27 billion tons of CO₂ released annually “create barriers for any carbon extraction and sequestration scheme,” he said. “Any industrial-scale process has environmental impacts, and there are few greater industrial scales than that of power generation. The sequestration industry would have to be of comparable scale.”

But despite his misgivings, Marburger admitted that over the long run, carbon capture and storage from coal-fired plants ranks alongside resolving the nuclear waste problem and minimizing nuclear proliferation risks as the best shots for minimizing climate change.

In December, DOE awarded $66.7 million to the Midwest Geological Sequestration Consortium for the fourth of seven proposed large-scale sequestration tests. Those tests are to assess the feasibility of storing millions of tons of CO₂ indefinitely in geologic formations deep underground. Three other awards with a combined value of $318 million were announced in October.

Major energy legislation enacted in 2007 authorized the seven projects and specified that each sequester a minimum of 1 million tons of CO₂ annually. The statute authorizes $240 million annually for the tests through fiscal year 2012, but appropriators provided just half that amount for the current year. To the extent possible, the law says, DOE should locate the projects in various geologic formations and use CO₂ produced in industrial operations. For the Midwest project, the gas will be supplied from fossil fuels burned at an ethanol refinery operated by Archer Daniels Midland Co and will be injected into the Mount Simon sandstone formation, which lies underneath four states.

The new law also authorized $30 million for a peer-reviewed assessment, administered by the Department of the Interior, of the available capacity for geologic sequestration in the US. And the legislation calls for recommendations from the National Academy of Sciences for establishing an interdisciplinary training program to produce specialists in carbon capture and storage.

Separately, $75 million is appropriated for DOE in FY 2008 for FutureGen, a cost-shared project with utilities to build an emissions- and carbon-free, coal-fired generating plant that will also employ geologic CO₂ sequestration.

At least two large-scale sequestration projects have been declared successes. Each year since 1996, Norway’s Statoil has been separating about a million tons of CO₂ from natural gas extracted from the North Sea’s Sleipner field and injecting it into a formation beneath the field. In doing so, the company avoids paying a steep tax of about 294 kroner (US$55) per ton that Norway has imposed on CO₂ emissions.

The second project, sponsored by DOE, the Canadian government, and several oil companies, met its goal of injecting 5 million tons of CO₂ into the Weyburn oil field in Saskatchewan. The liquefied gas was piped in from a synthetic fuels plant in North Dakota. The project’s expenses were offset by revenues from the thousands of barrels of oil that were pushed out of the reservoir each day by the injection. Indeed, CO₂ injection has been employed for years to extract oil that is not recoverable by conventional drilling.

As Marburger pointed out, even if the geological storage proves to be an unqualified success, it will be expensive to adopt. What he didn’t say is that in the absence of either a tax on CO₂ emissions or a cap-and-trade regime, industrial emitters will have little or no economic incentive to adopt the technology.