Emission Characteristics of Co-Combustion of Combustible Wastes with Coal in a Commercial Circulating Fluidized Bed Boiler

Fueled by ballooning oil prices and climate change concerns, municipal wastes are now regarded as being cheap and abundant resources. Combustible wastes could be converted into various types of energy such as fuel oil, syngas and electricity. To evaluate refuse-derived fuel (RDF) as a supplementary fuel in conventional coal-fired power plant, co-combustion tests with RDF and coal were carried out with different RDF/coal mixing ratios (1, 3 and 5%) in a 200 MW commercial circulating fluidized bed boiler. The properties of coal, RDF, fly ash and bottom ash from the boiler and the emission of pollutants were analyzed to investigate the effects of fuel ratios on the behavior of pollutants. No operation problems were observed and the HCl contents in the boiler were below 1 ppm regardless of fuel ratios, indicating the feasibility of co-combustion. Most of chlorines from RDF were fixed by limestones fed. The fly and bottom ash in the operation could be recycled since the contents of heavy metals were negligible.