Biomass combustion research studying the impact factors of NOx formation and reduction
¹ Kaunas University of Technology, Faculty of Mechanical Engineering and Design, Department of Thermal and Nuclear Energy, Studentų st. 56, LT–51424 Kaunas, Lithuania
²UAB ‘Enerstena’ Centre of Research and Development, Partizanų st. 89, LT–50312 Kaunas, Lithuania
Aim of this study was to identify potential NOx reduction factors and determine impact of nitrogen quantity in the fuel, during combustion process and conversion to nitrogen oxides. Experiments were performed using moving grate biofuel boiler with two staged air inlets, which represents industrial boiler operating principles. Combustion was performed using agricultural wastes: grain middlings, buckwheat hulls, corn pellets and mixtures with wood pellets. These types of fuels in combustion process generate about two times bigger amount of nitrogen oxides than wood pellets. The result of research shows, that the amount of nitrogen in the fuel has the greatest impact for NOx generation compared to all NOx formation forms. It was found that a smaller quantity of nitrogen, has bigger impact factor, than higher quantity of nitrogen, in biomass, for NOx formation during combustion. It was noticed that during combustion process the amount of carbon monoxide is inversely proportional to NOx values. The impact factor of nitrogen conversion to NOx and CO potential of reducing NOx is presented by formula in this paper.