On the Prediction of Pollutant Emission [NO<sub>x</sub>] in Internal Combustion Engine<i></i>

Abstract

The study of internal chemical processes involving nitrogenous species forms an important part in the understanding of parameters which lower NOx emission from combustion systems. The focus of this research is to numerically model the prediction of formation of pollutant emission in a continuous internal combustion engine (ICE), from finite rate chemical equilibrium equations. The main source of nitrogen in the chemical formation of NOx is atmospheric, and a very small portion is caused by nitrogen compounds found in some fuels. A mathematical modeling was carried out with these equations using MATLAB simulation to predict the concentration of Nitric Oxide NO; a pollutant, at different flame temperatures and reaction timing of ICE. The temperatures under consideration vary from 1500K to 2300K. The concentration of the pollutant was evaluated by the analytical and numerical methods for a spark ignition engine at a temperature of 2000K; pressure of 1atm, considering a sample containing 78% of Nitrogen and 4% of Oxygen and 78% Nitrogen and 21% Oxygen held between zero to one second in the course of the combustion process, while the computer programme simulated between zero and 100seconds. The concentrations predicted were found to increase as the flame temperature, the combustion time increase as depicted on the results and as the percentage composition of Oxygen in the mixture increases, but reduces with increasing fuel nitrogen content.