An article in the March 5 issue of the Economist questions the practicality of carbon capture and storage (CCS).
A recent American television advertisement features a series of trustworthy-looking individuals affirming their faith in the potential of "clean coal." ... The idea that clean coal, or to be more specific, a technology known as carbon capture and storage (CCS), will save the world from global warming has become something of an article of faith among policymakers too.
CCS features prominently in all the main blueprints for reducing greenhouse-gas emissions. The Stern Review, a celebrated report on the economics of climate change, considers it "essential." It provides one of the seven tranches of emissions cuts proposed by Robert Socolow of Princeton University. The International Energy Agency (IEA) reckons the world will need over 200 power plants equipped with CCS by 2030 to limit the rise in average global temperatures to about 3°C—a bigger increase than many scientists would like.
...Despite all this enthusiasm, however, there is not a single big power plant using CCS anywhere in the world. Utilities refuse to build any, since the technology is expensive and unproven. ... In short, the world's leaders are counting on a fix for climate change that is at best uncertain and at worst unworkable.
In a purely technical sense, CCS looks promising. There are several proven ways to isolate carbon dioxide from fossil fuels, using a variety of combustion techniques and an assortment of chemical “scrubbers” to react with the gas.
The problem with CCS is the cost. The chemical steps in the capture consume energy, as do the compression and transport of the carbon dioxide. That will use up a quarter or more of the output of a power station fitted with CCS, according to most estimates. So plants with CCS will need to be at least a third bigger than normal ones to generate the same net amount of power, and will also consume at least a third more fuel. In addition, there is the extra expense of building the capture plant and the injection pipelines. If the storage site is far from the power plant, yet more energy will be needed to move the carbon dioxide.
Dr. Gopal Rao
Web Science Editor
Editor, Meeting Scene
Materials Research Society (MRS)