Selected projects, which were processed by DWT-technology

History of DWT (steam fluidized bed drying)

Initial work on DWT-lignite drying were made in the 80s by Professor Potter on the Manash-University of Melbourne.


1980 - 1993


Developments of the DWT-lignite drying in East Germany:


  • 1980/81:

Study for the energetic and exergetic assessment of lignite drying at IfE Institute for Energy Leipzig, area Dresden,

  • 1982:      establishments of DWT-pilot plants in Zeithain/Saxony with 2 t/h lignite flow rate,
  • 1983-85:

DWT-process development for the complexes: technical process and equipment development, simulations of the DWT-process, determination of material data system of drying lignite in water steam etc. and complex experimental investigation of the DWT-method, drying of various products, such as Central German, Lusatian, Rhenish brown coal and Australian, Finnish peat, sewage sludge, wood chips etc.

  • 1985/86:

Development of expertise relating to DWT with vapor compression and lignite pre-heating by an international consortium of companies for the Rheinbraun AG. Basis for cooperation was the conclusion of license agreements between the IfE (Institute for Energy, area Dresden) and the companies Waagner-Biro, Lurgi, Saarberg-Interplan, Steinmüller and KHD to the construction of such DWT-plants.

  • 1986:      Construction of the first DWT-pilot plant Borna 1 with 20 t/h (partial deconstruction 1988),
  • 1989:      Construction of the DWT-prototype plant Borna 2 with 20 t/h, successful commissioning 1990,
  • 1991:      Construction of the pilot plant of the UET GmbH in Freiberg/Saxony with 0,25 t/h,
  • 1992:      Construction of the reference plant with 50 t/h in Loy Yang/Australia, built by Lurgi/Frankfurt,
  • 1993:      Deconstruction of the DWT plant in Borna and the entire briquette factory at the site in Borna.


With the political changes in 1990 in Germany, the development and use of lignite eastern Germany has been greatly reduced.


1993 - 2000


Further development of the DWT-technology for municipal and industrial sludges by CHOREN (UET Environmental and Energy GmbH) in Freiberg:


  • 1993:      Construction of the DWT plant for the PWA Waldhof Mannheim, 6 t/h (water evaporation),
  • 1994:      Construction of the DWT plant for papermill Steinbeis-Temming, 1,5 t/h (evaporation),
  • 1997:      Construction of the DWT plant for waste incineration in Amsdorf,  6 t/h (water evaporation).


1993 - today


Developments of the WTA (fluidized bed drying with using the waste steam) in West Germany by Rheinbraun/RWE Power AG:


  • 1993:      WTA I/II pilot plants in Frechen,
  • 2007:      WTA plant in Niederaußem with 210 t/h,


WTA-licensing by RWE to Uhde, Linde and other companies.


1993 - today


Developments of the DFT (steam-fluid drying) for the drying of poorly flowing bulk materials, pasty products and suspensions by VER GmbH:



2002 - today


Developments of DDWT (charged-pressure steam fluidized bed drying) at BTU Cottbus/Vattenfall:


  • 2002:      Pilot plant in Cottbus with 0,5 t/h raw lignite,
  • 2008:      Pilot plant in Schwarze Pumpe with 10 t/h.

Pictures from the DWT-plants Zeithain and Borna

Fore more information on DWT can be found under Downloads, Publications.