The Study and the Mechanism of Nitrogen Oxides’ Formation in Combustion of Fossil Fuels

Abstract

The burning of all fossil fuels is accompanied by the production of large quantities of nitrogen oxides. Nitrogen oxide from coal combustion is formed from the molecular nitrogen in the air and the nitrogen contained in the fuel. In accordance with the mechanism of formation of nitric oxide from fuel, it is desirable to increase the concentration of coal dust in the flame. The thermal regime of combustion accelerates the release of volatiles, with flames spreading out and the coke residue contributes to the chemical reduction of NOx. In this work we consider the specific issues of the formation mechanism of NOx fuel and ways to reduce their atmospheric emissions. Presented are results from the calculation of the influence of the following on the level of nitric oxides during coal combustion: temperature, oxygen concentration and time of release of fuel nitrogen. It has been established that the influence of nitric oxide fuel on the total nitric oxide emissions is more noticeable at low temperatures of the combustion process.

Study on Heat Transfer Characteristics and Performance of the Full Premixed Cauldron Stove with Porous Media

“…Finally, the thermal efficiency and heat losses of the stove are obtained. The following assumptions are made in the theoretical model: 1 The temperature at the bottom of the pot is uniform; 2 Since the high-temperature plane flame is formed close to the upper surface of porous media, it is assumed that the upper surface temperature of the porous media is equal to the flame temperature; 3 The heat dissipation of the stove wall is small, so the chamber wall is regarded as an adiabatic surface in the radiation heat transfer model; and 4 The natural gas is fully premixed with air, and the equivalence ratio of the mixed gas is 0.95.…”

“…Full premixed combustion [3] is a complete combustion method with low CO and NO X emissions. The fuel is fully mixed with air equal to or greater than all the air required for combustion in advance, and then it is sent to the combustion chamber for combustion.…”

Synthesis of Zeolitic Ti, Zr-Substituted Vanadotungstates and Investigation of Their Catalytic Activities for Low Temperature NH3-SCR

“…Nitrogen oxides (NO x ) are among the main pollutants generated by the combustion of fossil fuels. , The selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) is the most efficient technology to convert harmful NO x to harmless nitrogen (N 2 ) and water (H 2 O). ,− Vanadium oxide-based catalysts (e.g., V 2 O 5 /TiO 2 and V 2 O 5 –WO 3 /TiO 2 ) have been widely used in the industry for the removal of NO x because of their high N 2 selectivity and good thermal stability. , The SCR system is conventionally placed immediately after a boiler to gain heat to catalyze the reaction (>300 °C). However, this situation causes severe deactivation of the catalyst because it is exposed to ash and sulfates in the outlet gas.…”

“…19,20 Nitrogen oxides (NO x ) are among the main pollutants generated by the combustion of fossil fuels. 21,22 The selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) is the most efficient technology to convert harmful NO x to harmless nitrogen (N 2 ) and water (H 2 O). 8,23−25 Vanadium oxide-based catalysts (e.g., V 2 O 5 /TiO 2 and V 2 O 5 −WO 3 /TiO 2 ) have been widely used in the industry for the removal of NO x because of their high N 2 selectivity and good thermal stability.…”