Published online 18 January 2011 | Nature 469, 276-277 (2011) | doi:10.1038/469276a

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Low-cost carbon-capture project sparks interest

Consortium to determine whether price reductions seen in China can be applied abroad.

A facility at Shidongkou No. 2 Power Plant in Shanghai, China, scrubs carbon dioxide from flue gases for a cost per tonne of CO2 that is far below prices elsewhere.HUANENG GROUP

The Shidongkou No. 2 Power Plant outside Shanghai, China, has hosted a parade of foreign visitors in recent months, from academics and industry officials to US energy secretary Steven Chu. All have had one question on their minds: have Chinese engineers turned a corner on carbon-capture technology?

That question occupies a small but significant place in a package of clean-energy research initiatives expected to be announced this week as Chinese President Hu Jintao meets US President Barack Obama in Washington DC from 19 January.

The buzz began in late 2009, after officials at the government-owned Huaneng Group opened a facility that captures some of the carbon dioxide emitted by the existing giant 1,320-megawatt coal-fired Shidongkou power station. The system scrubs roughly 120,000 tonnes of CO2 a year from 3% of the facility's flue gases, but what has caught everybody's eye is the cost that Huaneng quotes: a mere US$30–35 per tonne of CO2, including the further expense of purifying the captured gas for use in the food and beverage industry.

That is far below the $100 or more typically estimated for first-generation projects to retrofit existing power plants for carbon capture and storage (CCS) in the United States and Europe, and it is within the range of past carbon prices in the European Union emissions trading system. If similar cost reductions can be realized elsewhere, they could cut years off the timetable for commercial introduction of retrofitted CCS technology, touted as a way to reduce the climatic impact of existing coal plants. Experts want to know how the Chinese facility is doing it, and whether the savings could be exported.

During Hu's US visit this week, officials are expected to announce an initiative that will see a consortium of government, academic and business interests from the United States and China conduct a coal-technology assessment that could provide some answers. "A lot of people want to know whether that work will translate into other markets, and I believe we'll be able to shed a lot of light on that question," says Julio Friedmann, carbon-management programme leader at Lawrence Livermore National Laboratory in Livermore, California. Friedmann also serves as technical director for the US–China Advanced Coal Technology Consortium at West Virginia University in Morgantown, which was established last September as part of an energy partnership and will conduct the assessment.

The Shidongkou retrofit builds on the work of a smaller facility, installed at the Gaobeidian power plant in Beijing in 2008 (see Nature 454, 388–392; 2008). Both installations use a common CCS technology: CO2-rich flue gas from the plant is bubbled through a column containing an amine-based solvent — in this case, a mixture of ethanolamine and additives — that reacts with the gas and takes up its carbon dioxide. The solvent is then heated to release the CO2, and the whole process starts again. In addition to the direct costs, this process is normally expected to gulp 25% or more of a plant's energy output when fully scaled up, making it a tough sell for power companies.

Huaneng has not yet revealed all the technical details of its CCS process. Huang Bin, head of Huaneng's Research and Development Division in Beijing, says that the company has made unspecified changes in the design of the plant and the chemistry of the solvent, which increased the energy efficiency of the system by 11–14% and reduced the cost of installation by a factor of 10 per tonne of CO2.

"Huaneng is using a known process, but they seem to have found a way to do it much more economically," says David Mohler, chief technology officer of Duke Energy, an electric utility company based in Charlotte, North Carolina. "What's the secret sauce?" he adds.

The cost that Huaneng quotes for capturing the carbon dioxide before purification — around $20 per tonne — is four to five times lower than anything anybody else is reporting, says Mohler. Duke Energy has a partnership with Huaneng and has been planning to analyse the cost of installing and running Huaneng's technology at its Gibson Station power plant in Indiana; Mohler says that joining the consortium's broader assessment will bolster the Gibson analysis and help put this technology in context with other options.

However, Howard Herzog, a chemical engineer researching carbon sequestration at the Massachusetts Institute of Technology in Cambridge, says a deeper inspection of the Shidongkou facility might reveal that its secret comes down to things such as cheap labour and fewer regulatory burdens. "The fact that it's cheaper in China doesn't impress me," says Herzog, who recently toured the facility. "Everything is cheaper in China."

Sarah Forbes, a carbon-sequestration expert at the World Resources Institute, an environmental think tank in Washington DC, says that Huaneng's costs for carbon capture are in proportion with general costs in the Chinese coal industry, which tend to be about one-third of those in the United States.

Ming Sung, who promotes US–Chinese business alliances in Beijing on behalf of the Clean Air Task Force in Boston, Massachusetts, acknowledges that costs will be higher in places such as the United States, but says that the question is how much. Assuming that Huaneng has made some industrial progress, he says, its technology will probably still be cheaper than anyone else's at this stage.

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That may not be enough to jump-start the technology, Forbes cautions. "Adding carbon capture to a power plant still comes with a significant cost and energy penalty" that will discourage adoption, she says, and the regulatory drivers necessary to encourage or force take-up are still missing.

Nonetheless, EmberClear, an energy company based in Calgary, Canada, has licensed a suite of Huaneng's clean-coal technologies — including the capture technology in place in Shanghai — for deployment in the West. Albert Lin, chief executive of EmberClear, says the cost reductions that Huaneng has achieved at Shidongkou are probably the result of a mixture of practice and Chinese economics. "Half of it is Chinese costs, but there are definitely improvements in how the technology is being used," he says.

To Friedmann, Shidongkou No. 2 has become a critical case study for exploring actual CCS costs, because of its scale and the real operational data that Huaneng is providing. "There are not that many places where we are going to have the kind of data we are looking for," says Friedmann. "They are the forerunners." 

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  • #62289

    That's not really scientific. Waves dissipate over distance. Anyway, I live over 100' above sea level. I":http://jocurinoidegatit.tumblr.com/ wouldn't take anything anywhere.

  • #62291

    That's not really scientific. Waves dissipate over distance. Anyway, I live over 100' above sea level. I wouldn't take anything anywhere.

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