Reduction of combustion by-products in WTE plants: O-2 enrichment of underfire air in the MARTIN SYNCOM process

The SYNCOM process involves oxygen enrichment of underfire air, recirculati on of flue gas and a combustion control system using infrared thermography of the waste layer on the grate. At the demonstration plant in Coburg, oper ational reliability and plant availability using SYNCOM could be proven und er real disposal conditions with a waste throughput of 7 t/h. Oxygen enrich ment of the underfire air promotes the destruction of pollutants due to the high oxygen partial pressures and temperatures. This is then reflected in very low residual amounts of organic combustion by-products in the bottom a sh and flue gas from the SYNCOM unit. The flue gas concentrations of organi c pollutants are reduced, as compared with conventional operation, by over 35% (for CO, total hydrocarbons and PCDD/F) at the boiler outlet. As the fl ue gas flow is reduced by oxygen enrichment and Rue gas recirculation, the resulting reduction in terms of kg of pollutant per Mg of waste is even hig her. In the bottom ash, the level of organic residues is reduced, by 45% in the case of loss on ignition and by 55% in the case of TOC and dioxins (I- TE of PCDD/F). This is due to the higher oxygen partial pressures and the f uel bed temperature which is increased by 135 to 1200 degreesC. Other impor tant features of the process include more intense sintering and thus improv ed immobilization of the bottom ash, as well as reduced hue gas and fly ash flows. (C) 2001 Elsevier Science Ltd. All rights reserved.