RWE Power to build fluidized-bed drying plants

This turns Linde-KCA-Dresden into a provider and supplier of WTA developed by RWE Power. WTA is the German abbreviation for fluidized-bed drying with internal waste-heat utilization.

"In Linde-KCA-Dresden, we have won a renowned partner with comprehensive experience and international know-how in building chemical plants. This is an important step in the worldwide dissemination of the WTA technology now being demonstrated at Niederaussem," stresses Dr Johannes Heithoff, head of research and development at RWE Power, adding: "In the future it is to be deployed in lignite-based power plants and in coal-gasification and liquefaction projects to obtain more energy-efficient and lower-CO2 electricity and synthesis-gas production".

"We look forward to the long-term partnership with RWE. Thanks to the bundling of the experience and expertise available in the two companies, we will be able to offer even better, tailored-to-suit, commercial-scale solutions for climate-sparing CO2 reduction in the future. At the same time, this cooperation with RWE enables us to tap new markets," says Jörg Linsenmaier, managing director of Linde-KCA-Dresden GmbH.

The technology, developed by RWE's own engineers, is a registered trademark. Thanks to WTA, the efficiency of future lignite-fired power stations will be increased by ten per cent to over 47 percent. In a 1,000-MW power plant, this will reduce CO2 by up to one million tons annually with the same amount of power being generated. Moreover, WTA drying is indispensable for the gasification of lignite to make fuels or for the products of the chemical industry. WTA technology lowers the moisture content of raw lignite from over 55 percent to 12 percent. The crucial advance: by contrast with the previous drying process with flue gas at 1,000°C, WTA drying at 110°C is much more favourable in energetic terms.

Also, the heat expended on drying the coal is now largely recovered and re-used. By comparison: to achieve a similar effect for the climate, nearly 500,000 mid-size cars would have to stay in their garages forever.

At Niederaussem, RWE Power has been operating a demonstration prototype plant on a commercial scale since February 2009, generating 110 tons of dry lignite an hour. This is equivalent to up to 30 percent of the entire coal requirements of the BoA unit in Niederaussem, currently the most efficient lignite-fired power station with optimized plant engineering (BoA) featuring an efficiency of over 43 percent. Use of the demonstration plant reduces CO2 by 240,000 tons a year. RWE Power has invested EUR 50 million in the project.