Characteristics of RDF char combustion in a bubbling fluidized bed

The feasibility of applications of the char obtained from a gasification process of municipal-waste refuse derived fuel (RDF) as an auxiliary fuel was evaluated by combustion experiments. The higher heating value of the RDF char was 3000∼4000 kcal/kg and its chlorine content was below the standard requirement demonstrating its potential as an auxiliary fuel. In the combustion exhaust gas, the maximum NOx and SO2 concentrations were 240 ppm and 223 ppm, respectively. If an aftertreatment is applied, it is possible to control their concentrations low enough to meet the air pollutant emission standard. The HCl concentration was relatively high indicating that a care should be taken for HCl emission from the combustion of RDF. Based on the temperature distribution within the reactor, the concentration change of O2 and CO2, and the amount and the loss on ignition of solid residue, it was inferred that the combustion reaction was the most reliable when the excess air ratio of 1.3 was used.