Analysis of the Flue Gas Produced During the Coal and Biomass Co-combustion in a Solid Fuel Boiler

Abstract

As the low emission of particulate matter (PM, or ‘floating dust’) and gaseous pollutants from coal-fired boilers is the main source of air pollution in Poland, more environmental-friendly alternatives for coal combustion should be considered. One of them is the co-combustion of coal and biomass. The following article describes the experimental co-combustion of different coal-biomass blends with the use of Galmet boiler, which is a part of a mobile educational installation designed by the AGH University of Science and Technology and Galmet. The research is concentrated on flue gas composition changes connected to the rising content of biomass in the blends. The flue gas composition was measured with the use of Testo 350 and Testo 380 probes. The combusted coal-biomass blends contained 10 wt%, 20 wt%, and 30 wt% of biomass pellets. The flue gas composition was also compared to the flue gas produced during the coal combustion in the same boiler. The results show that with the rise of the biomass content in the blend, the NO and NO2 content drops significantly, and in the case of blend with 30 wt% of biomass, no NO2 emission was detected. The SO2 content in the case of 10 wt% blend is slightly higher than the SO2 content in flue gas from coal combustion, but its content drops in the case of the 20 wt% and 30 wt% blends. No clear correlation between PM emissions and the biomass content in the blends was observed.