As the U.S. Department of Energy's first-of-its-scale project in carbon burial launches, interest in carbon burial and sequestration is at an all time high. Many nations wish that there was an alternative to traditional emissions cuts, which can hinder growth, and could reduce their net contribution to atmospheric carbon.
Carbon sequestration could provide just such a solution. By burying the substance in underground cavities or in carbon rich soils in swamps or other sites, the net contribution of a country to emissions can be reduced. And while many in the environmental community no longer like the idea, pointing out that such deposits could be easily released and don't solve the overall problem, the movement to adopt carbon sequestration still has powerful supporters.
Drilling began this week in Illinois on the DoE project, which will bury one million metric tons of carbon dioxide into the ground by 2012. The project is the first of its scale in the U.S., and while still small compared to total U.S. emissions has the potential to grow much bigger. Illinois, Indiana, and Kentucky have enough underground space to store approximately 100 billion tons of CO2, enough to completely negate 25 years of emissions at the current rate, if fully filled.
Robert Finley, the manager of the current project states, "This is going to be a large-scale injection of 1 million metric tons, one of the largest injections to date in the U.S."
While Mr. Finley is enthusiastic about the project, others aren't. The Bush administration last year canceled funding for an even bigger carbon sequestration project, FutureGen, citing concerns about the practice. The Intergovernmental Panel on Climate Change, typically a strong voice in support of emissions control, has sided with the utilities for once in vocally opposing carbon burial. It has released studies indicating 30 percent of the energy from a coal burning plant would be wasted trying to capture the carbon dioxide from the flue gas.
One thing that could give supporters of burial a boost though is new carbon-specific filtering materials produced in labs like Omar Yaghi's at UCLA and at Georgia Tech under Chris Jones. These materials may potentially make capture much cheaper and more efficient, making storage the only remaining challenge.
John Litynski, who works in the fossil-fuel-centered National Energy Technology Laboratory's Sequestration Division, believes storage should be easy as pie for the U.S. He states, "What we found in the U.S. with the research that we've done over the last 10 years is that there is a significant potential to store CO2 ... in these very large reservoirs that are underground."
However, many of these reservoirs are deeper underground that existing sequestration projects have reached. That's why the deep reaching Illinois project, which drills into the Mt. Simon sandstone, is such a critical test bed. Scientists will, for the first time, be able to observe what happens when they pump compressed carbon dioxide 6,500 feet below the surface. Describes Mr. Litynski, "We have numbers for what we think the capacity is in the U.S., but the only way to prove that is to actually drill a well."
The Illinois project will pump carbon dioxide produced by ethanol fermentation underground. Archer Daniels Midland provided land for the site. Even with these concessions, the project will cost over $84M USD, thanks to the high cost of drilling.
At a recent speech Mr. Litynski was challenged by an audience member who pointed out that 10,000 projects of the scale of the Illinois one would be needed to offset current emissions. Mr. Litynski refused to back down from his support of the concept, though, dodging the question and stating, "From my point of view as someone working in this field ... the political rhetoric gets to the point where it's all supposed to be solar or wind or coal or natural gas (versus sequestration). The reality for the situation is that we need all of these technologies."
quote: The small nuclear reactors you refer to are commonly referred to as nuclear 'batteries'...However these are tiny reactors in the 25 Megawatt class, not the 1000+ Megawatt reactors used for commercial power generation. They are good for remote locations, but they are not designed to be refueled...You also have a problem of security and nuclear proliferation since the bomb grade Pu239 is easily extracted via chemical means. No difficult isotope separation is needed
quote: A few corrections here. A "nuclear battery" is an RTG, not a reactor. A few different companies (Toshiba, Hyperion,etc) are commercializing small nuclear reactors, some of which are indeed designed to be refueled.
quote: Furthermore, it's rather trivial to design a reactor that generates very high levels of 240Pu, which quite effectively poisons the 239Pu, preventing it from use in a nuclear weapon without purification through isotopic separation.
quote: This must be some new use of the term. A nuclear battery is used to refer to generation by spontaneous decay, rather than forced fission.
quote: No. It depends on the neutron flux within the reactor. Even in a normal LWR, you'll break 20% within a fuel rod's normal lifetime, and with some designs, you can achieve substantial 240Pu poisoning within weeks, long before significant quantities of 239Pu have been generated.