Chemical kinetics analysis of NO and CO formation based on thermodynamic data from an ethanol-fueled engine computational model

Abstract

A series of theoretical analyses of pollutant formation has been undertaken on a computer program based on temperature and volume data from a two-zone internal combustion engine model. The objective was to predict the formation of nitric oxide and carbon monoxide during combustion process in an ethanol-fueled engine before the three-way catalyst operation. The predictions were based on a chemical kinetics model, which considered 12 chemical species and 22 chemical reactions. The model calculated the reaction rates from the beginning of the combustion process until chemical kinetics calculations showed no effect on the gases composition during expansion. The developed analysis tested some temperatures in order to discover until when chemical kinetics effectiveness was considerable. This analysis involved the study of NO and CO formation rates. The considered range of temperatures was between 2500 and 1500K, typical engine temperatures during combustion and expansion processes. Results showed that NO and CO formation were qualitatively coherent when compared to known formation measures by ICEs presented on literature. The studied temperatures allow the possibility of maintaining constant the concentration of some species from specific moments during expansion process, without changing significantly formation results