Modeling of Co-firing Coal-Feedlot Biomass Blends in Swirl Burners and Associated NO Emissions

摘要

Co-firing technology is becoming popular in the electric utility industry for the many potential benefits it offers. Some of the benefits include reduction in gaseous emissions, possible reduction in fuel costs, low implementation costs and proper waste disposal. In the present study, a 90% coal and 10% feedlot biomass (mass basis) co-firing case is modeled and predictions are compared with experimental data obtained at our small-scale boiler burner facility. Predictions of the NO emissions are the primary focus of the study. Sensitivity analyses are carried out for swirl number and percent excess air. It is found that swirl plays an important role in determining the flame shape and the resulting NO emissions. Similarly, excess air has a direct impact on NO emissions, with an increase in percent excess air leading to an increase NO emissions.