April 30, 2014
Researchers from the £ód¼ University of Technology in central Poland are working to develop a system to capture mercury from flue gas. The project is the first of its kind in the world.
Just 20 years ago, the air in Poland was polluted mainly due to significant amounts of flue gas and smoke coming from factory chimneys and coal-fired power plants. And although the situation is much better today, Polish researchers are still working to reduce emissions of harmful substances into the atmosphere and trying to capture toxic elements and compounds.
Researchers from the £ód¼ University of Technology, together with experts from PGE Górnictwo i Energetyka Konwencjonalna, are working to develop and implement technology to reduce mercury emissions resulting from coal combustion. PGE Górnictwo i Energetyka Konwencjonalna is the company that runs the Be³chatów power plant, south of £ód¼, the largest lignite-fired power plant in Europe.
The researchers are building a semi-industrial-scale system for capturing some of the mercury contained in the flue gas emitted by the Be³chatów power plant. Flue gas emitted through a chimney encounters a special sorbent that absorbs the mercury contained in the gas.
The sorbent works selectively: it does not absorb other compounds contained in the flue gas. It can be reused and is relatively cheap. The parts covered with the sorbent on which the mercury settles are moved to a special furnace where a desorption process takes place—the mercury is removed. The sorbent is then recycled.
The researchers have applied for a patent for their design, according to the project manager, Prof. Ma³gorzata Iwona Szynkowska from the Faculty of Chemistry at the £ód¼ University of Technology.
Research is under way to optimize the work of the system under real conditions, in industry, as opposed to ideal laboratory conditions. The method is the only one of its kind in the world—until now, no such technology existed. The patent protecting this unique technology has been expanded to cover the whole of Europe and the United States.
“Our technology is completely different from that used in the U.S. and much cheaper,” says Prof. Krzysztof Jó¼wik, director of the Institute of Turbomachinery at the £ód¼ University of Technology, who is also responsible for the design of the system. “The agreement with PGE, which is a part of the project, says that if, within five years, the power plant decides that the technology is up to scratch, it will be put in into practice in industry. Our task is to provide them with the guidelines on how to build and launch the installation on an industrial scale.”
Even though the system is largely universal, the researchers say, its installation in specific industrial facilities such as power plants, incinerators or cement plants will involve certain additional costs. Each facility has a different design, infrastructure and performance characteristics in terms of fuel, access to water and so on. Therefore, the technology must be adapted to each facility. Also, auxiliary devices such as additional fans and measurement systems will require individual studies. Meanwhile, new emissions standards will be introduced in 2016. If these turn out to be different for each sector, the technology will also have to be adjusted to their specific requirements.
Although the amount of mercury in flue gas is very small, the massive amount of smoke emitted by industry means that it may be profitable to extract and sell it commercially. This could be an additional factor encouraging companies and institutions to buy the system developed by the researchers.
The project is being financed by the National Center for Research and Development (NCBiR) and its total budget is zl.22 million.
Danuta K. Gruszczyńska