Effect of preheating Co-firing of biomass and coal on the synergistic reduction of PM and NO source emissions

Abstract

Co-firing of biomass and coal is a prevalent method in modern thermal power plants to reduce pollutant emissions. This study focuses on the preheating co-firing behavior of coal and biomass to explore the effect of preheating combustion and preheating co-firing on PM (particle matter) and NO source emissions, and different coals were selected to verify the effect of coal rank on this behavior. Coal and biomass were fed into a mixing device through two independent feeders and uniformly mixed before entering the furnace. PM and NO emissions after preheating combustion were measured using an Electrical Low-Pressure Impactor and flue gas analyzer. The results showed that preheating combustion reduced the production of PM1, PM1-10, and NO from coal by 22.30%, 10.75%, and 49.84% respectively, and also reduced the production from biomass by 28.61%, 15.16%, and 53.01% respectively compared to conventional combustion. Preheating co-firing experiments revealed that as the co-firing ratio increases, NO production decreased, but the production of PM1 initially decreased and then increased, reaching a minimum point at a co-firing ratio of 25%. Meanwhile, the lower the rank of the coal, the better the effect of preheating combustion and preheating co-firing, and the ash content and composition of coal also had an impact on the generation of PM1.