Effects of corn ratio with pine on biomass co-combustion characteristics in a fixed bed

In this study, the effect of corn ratio on pine chip and corn straw (high alkali metals and chlorine) co-combustion in a fixed bed were investigated. The combustion efficiency, gas emissions, and problems of corrosion and deposits were analyzed by detecting bed temperatures, gas compositions (CO2, CO, O2, CH4, C2H6, NOx, HCN, NH3, SO2, and HCl), and alkali metal emissions. The appropriate increase in the corn ratio improved flame propagation speed and shortened ignition time. Pure pine combustion caused some amount of thermal NO emissions, and the high content of N resulted to a relatively high emission of NH3 and HCN, whereas its relationship with the release of NO in the main burning stage was slight. A 30% corn ratio aided in the reduction of NO emission, and the amount of alkali metals in the corn fixed the effect of SO2. The release of KCl and HCl can be considered as the prevalent emission formation of Cl in the blended biomass co-combustion process; the additional corn straw increased the release ratio of metal chloride. The optimum corn ratio (30-50%) provide a certain reference value for the selection of fuel mixture ratio in the operation of real large-scale systems.