Experimental investigation on biomass combustion in a pilot-scale circulating fluidized bed combustor

The combustion of biomass was studied experimentally in a 0.5MW circulating fluidized bed combustor. Sugarcane, bark and sawdust were used as feeding materials. During the combustion process, the bed temperature was kept at a low level (750 °C) to inhibit ash melting and overcome agglomeration. The temperature distributions along the height of furnace and combustion efficiency were analyzed. In addition, the influence of air staging on NO emission has been investigated. The results showed that most part of biomass combustion occurs in the freeboard. The combustion efficiency can be high even at low temperature, and the value reaches 99.07% in the sugarcane run. Moreover, the adoption of secondary air not only reduces the flue gas CO concentration, but also suppress the NO formation to some extent. The results of this study can provide guidance for industrial practice.