Furth recycling plant to enter service this fall

All four conversion drums for the first commercial-scale thermal waste recycling plant, currently under construction in Furth, Germany, by the Siemens Power Generation Group (KWU) have arrived on site. The conversion, or carbonization, drum is the heart of this thermal waste treatment process.

The drums, each weighing 110 metric tons and with a length of 22 meters, were transported by ship from the CAS Stassfurt manufacturing plant in the German state of Saxony-Anhalt to Furth. Following installation of the combustion chambers and heat-recovery steam generators at the end of 1995, all major components have now been installed in the plant. Construction and installation are approaching completion, and commissioning is scheduled for fall of 1996.

The plant will process more than 100,000 metric tons of waste annually with two process lines, each with two conversion drums. Using this process, approximately 4,500 metric tons of sorted ferrous metal and around 500 metric tons of cleaned aluminum can be recycled annually and sold as high-grade secondary raw material. A mixed fraction of glass, grit and ceramic material, and the product from the combustion process–granulated slag, which is highly resistant to leaching–can be used directly in building and road construction.

Plant operator will be Umwelttechnik Mittelfranken GmbH, a joint venture between Frankisches Uberlandwerk and Recon GmbH.

In the thermal waste recycling process, the residual waste is treated in the conversion drum at a temperature of 450 C in an oxygen-depleted atmosphere. The process gas, which is produced, is fed directly to the downstream high-temperature combustion chamber. The solid, noncombustible components of the waste–such as glass, grit, ferrous metals and aluminum–are discharged, sorted and cleaned after the carbonization process and are then reintroduced into the industrial cycle.

The carbonaceous dust produced in the conversion drum is pulverized and combusted together with the process gas. The final product is a granulated slag. Organic substances such as dioxins and furans are totally destroyed by the high combustion temperature–1,300 C. Inorganic pollutants are immobilized in the slag, which can then be used by the construction industry. One metric ton of raw waste yields only 3 kilograms of waste requiring disposal in a hazardous-waste facility.