With the supply and installation of plant and equipment for the replacement of an ash transport and disposal system in a Serbia’ Kostolac B coal-burning power plant, German company Engineering Dobersek is helping environmental protection. Kostolac B produces 300 t/h of dry ash and 33 t/h of bottom ash when under load. Out-dated methods of ash transport and disposal were ruining the groundwater and polluting the air. Furthermore, the old ash disposal lagoon borders on the two rivers Danube and Mlava. At times of high precipitation the dams of the old disposal lagoon could break and hazardous substances stored for many years could be washed into the Danube. This would release an environmental disaster affecting not only Serbia, but also neighbouring states downstream: Romania, Bulgaria, Moldavia and the Ukraine.

Building a new ash disposal lagoon at a 7-km distance would not solve the problem completely. The plant was looking for up-to-date technology for ash transport and long term disposal complying with European environmental standards. Engineering Dobersek, as part of a consortium, was awarded a €20 million contract, having presented the most economic, innovative and environment-friendly concept. The concept contains extensive construction of the plant for transport, temporary storage as well as disposal of dry and bottom ash.

For transportation, at the plant the dry ash will be mixed at a ration of 1:1 instead the previous ratio of 1:10. It offers three important ecological and economic advantages:

• water demand will be reduced to a tenth
• due to the reduced volume of consolidated ash a smaller disposal lagoon area is required
• advanced ash solidification on the lagoon surface means better dust prevention and reduction of ground water pollution in case of heavy precipitation.

Furthermore, the innovative technologies of the consortium make possible not only professional disposal of dry and bottom ash but also will allow recycling: dry ash can be used for cement production and the bottom ash for road works. The contract is financed by the European Bank for Reconstruction and Development (EBRD). Completion is scheduled for April 2008. www.ed-mg.de