NO-Reduction by Ethane in a JSR at Atmospheric Pressure: Experimental and Kinetic Modeling

Abstract

The reduction of nitric oxide (NO) by ethane in simulated reburning conditions has been studied in a fused silica jet-stirred reactor operating at 1 atm, in the temperature range 900-1400 K, in diluted conditions. In the present experiments, the initial mole fraction of NO was 1000 ppm, that of ethane was 4400 ppm. The equivalence ratio has been varied from 0.75 to 2. It was demonstrated that the reduction of NO varies as the temperature and that, for a given temperature, a maximum NO reduction occurs slightly above stoichiometric conditions. Then, optimal NO-reburning conditions can be achieved for particular combinations of equivalence ratio and temperature. The present results generally show the same trends as observed in previous studies using simple hydrocarbons or natural gas (NG) as reburn fuel. A detailed chemical kinetic modeling of the present experiments was performed using an updated and improved kinetic scheme (877 reversible reactions and 122 species). An overall reasonable agreement between the present data and the modeling was obtained although improvements of the model are still necessary. The proposed kinetic mechanism, already successfully used to model the reduction of NO by ethylene, acetylene and HCN, and the low temperature interactions between NO and simple alkanes in a JSR, was also validated through the modeling of the reduction of NO by a NG blend. According to this study, the main route to NO-reduction by ethane involves kete-nyl radical. The model indicates that the reduction of NO proceeds through the reaction paths: HCCO + NO → HCNO + CO followed by HCNO + H → HCN + OH; HCN + O → NCO → HNCO → NH₂; NH_i + NO → N₂; NH + NO → N₂O; N₂O + H, O → N₂

Keywords:

• reburning
• kinetics
• combustion
• modeling
• natural gas
• ethane

Additional information

Notes on contributors

PHILIPPE DAGAUT

Corresponding author: Dr. Philippe Dagaut C.N.R.S., L.C.S.R. 1 C, Avenue de la Recherche Scientifique 45071 Orléans Cedex 2, France Phone: [phone]; Fax: [phone] E-Mail: [email protected].