Control of the emission of NOx during coal combustion by inhibiting the formation of NOx precursor in the pyrolysis process

Abstract

NOX emitted from coal combustion cause serious pollution to the ecological environment. At present, controlling and reducing NOX emissions has become one of the most important technologies to control the pollutants in the atmosphere. Due to the formation of a large amount of NOX precursor HCN, NH3, char-N during coal pyrolysis, and these nitrogen species with O2 in the air cause the emissions of NOx during combustion. Therefore, it is of great significance to study the control of NOX precursors during coal pyrolysis. The addition of additives to coal has an important catalytic effect on the control of NOX precursors during coal pyrolysis. In this paper, the catalytic effect of additive Fe, Ca, Na on nitrogen transport during pyrolysis of raw coal or demineralized coal was discussed. It can be concluded that Fe, Ca, Na can catalyze the conversion of NH3, HCN and char-N to N2, thus reducing the NOX precursor in the pyrolysis of coal and reducing the emission of NOX in the subsequent combustion process. The result provides an important scientific basis for the control of NOX emission by reducing NOX precursor formed in pyrolysis during coal combustion.