The estimation of fuel nitrogen distribution during the devolatilization process of coal by TG-DTG-MS analysis

Abstract

The emission control from coal-fired power plants is on a global level in focus last decades due to environmental issues. The emission of nitrogen oxides is recognized among the other pollutants, as the key environmental problem related to energy production by the coal utilization. In this paper, the effect of fuel nitrogen delivery on the NOx precursors (HCN and NH3) during devolatilization processes of selected coal samples (with high content of nitrogen) has been examined. TG-DTG coupled with mass spectrometry (MS) experimental techniques was used for the assessment of nitrogen distribution for HCN and NH3 as intermediate species during coal devolatilization, which directly influences the emission of nitrogen oxides during the combustion process. Further by the establishment, the mass balance of nitrogen together with performed analysis of evolved gases, the distribution of nitrogen between volatiles and char could be also determined. The obtained data for particular coal samples could be exploited for further coal combustion process optimization in regard to NOx emissions, and can be used as the experimentally determined input parameters for mathematical modeling of the coal combustion process, in the large-scale coal-fired power plants.