Emissions of flue gas during pulverized combustion of coal and waste woody biomass

Abstract

In this paper results of research of co-firing coals from Middle Bosnian basin with waste woody biomass are presented. The research was conducted in the laboratory at the Faculty of Mechanical Engineering in Sarajevo. Tested fuels were subjected to pulverized combustion under various temperatures and various technical and technological conditions: different mass ratio of fuel components in the mixture, different coefficient of excess air for combustion, classic and staged air supply, and fuel staged into the reaction zone. The results are related to the emission of flue gas components with respect to the technological conditions of combustion. In addition to the valorization of the influence of the primary fuel composition and process temperature on the emission values of the flue gas components, it has been shown that the application of primary measures in the combustion chamber results in lower or higher positive effects in terms of reducing the emissions of individual components -e.g. the NOx emission is reduced from 837 mg/mn3 in conventional combustion to 710 mg/mn3 using air staging, while during combustion with fuel staging, the NOx emission is reduced in proportion to the part of the fuel that is introduced into the reaction zone subsequently.