The characteristics of air pollutants from the combustion of biomass pellets

Abstract

ABSTRACTBiomass is renewable clean energy. The aim of this study is to explore the combustion properties and emission characteristics of NOX, SO2, PM, and HCl in the combustion process of biomass pellet fuels. In this study, three kinds of fuels (pine sawdust, mixed wood, and corn straw) were selected to be studied by using a tube furnace to simulate industrial boiler. Experiments were conducted under different combustion conditions (combustion temperature and air flow). The results show that pollutant emissions were related to fuel type, combustion temperature, and air flow. The emissions of NOX were contingent on N content in the fuel and the peak emissions of NOX appeared in the range of 50~600 mg/m3 at 4 L/min and 700℃. The emissions of SO2 were related to combustion condition and close to zero under the condition of sufficient combustion. The emissions of HCl and particulate matter (PM) increase with the rise of temperature, but the emission of PM was minimal at 800℃. Average HCl emission was 0.2~0.5 mg/g under steady-state conditions (4 L/min and 700℃). All in all, the pollutant emissions of biomass pellet fuels during combustion are lower than those of the traditional fuel, and the combustion efficiency is relatively higher.