Combustion test of refuse derived fuel in a fluidized bed

Abstract

Power generation from refuse derived fuel (RDF) is one of the promising technologies for the utilization of municipal solid waste. To understand the combustion behavior of two kinds of RDF burnt in a fluidized bed incinerator, commercial sized RDF was fed continuously into a 0.3×0.3 m 2 and 2.73 m high bubbling type fluidized bed combustor. Gases such as CO, NO x , SO x and HCl concentrations in the flue gas from the combustor were detected by a continuous measurement system. It was found that, for RDF-A which is lower in density and strength than RDF-B, the concentrations of CO in flue gas are high and are strongly affected by the air ratio. When secondary air was injected, the CO concentrations for both RDF-A and RDF-B were decreased. The increase in the air ratio led to an increase of NO x concentration when only primary air was injected at a bed temperature of 1073 K. The addition of secondary air effectively reduced the NO x level for both RDF-A and RDF-B. The temperature where the HCl concentration was the lowest was about 1073 K. Nonetheless the concentrations of HCl were always less than 60 ppm in all experiments. The HCl removal ratio by the calcium compound was higher than 70% even though the bed temperature was higher than 1173K. This indicates that the added calcium compound in the RDFs effectively controlled the HCl emissions.