MUTUAL SENSITIZATION OF THE OXIDATION NO AND AMMONIA: EXPERIMENTAL AND KINETIC MODELING

Abstract : The selective non-catalytic reduction of NO by ammonia (SNCR) has been extensively studied. Recent experiments performed in a jet-stirred reactor (JSR) at atmospheric pressure for various equivalence ratios (0.1-2) and initial concentrations of NH 3 (500 to 1000 ppm) and NO (0 to 1000 ppm) revealed kinetic interactions similar to mutual oxidation sensitization of hydrocarbons and NO. The experiments were performed at fixed residence times of 100 and 200 ms, and variable temperature ranging from 1100 to 1450 K. Kinetic reaction mechanisms were used to simulate these experiments. According to the most reliable model, the mutual sensitization of the oxidation of ammonia and nitric oxide proceeds through several reaction pathways leading to OH production, mainly responsible for ammonia oxidation in the current conditions: NH 2 +NO → NNH+OH, NNH → N 2 +H, NNH+O 2 → N 2 +HO 2 , H+O 2 → OH+O, H+O 2 +M → HO 2 +M, and NO+HO 2 → NO 2 +OH. Introduction Thermal de-NO, also called selective non-catalytic reduction of NO by ammonia (SNCR), is a common NO reduction technique which is efficient in a small temperature range centered around 1200-1250 K. Many experimental and modeling studies concern SNCR [1-5]. However, existing kinetic models show weaknesses and sometimes fail to represent the kinetics of ammonia oxidation [6] whereas interest for this fuel is growing. Nowadays, ammonia is viewed as an alternative zero-carbon fuel which presents potential for future power stations [6]. In this context, ammonia combustion in a gas turbine was recently demonstrated in Japan [7]. However, its combustion needs further studies [6] and kinetic interpretation needs further investigations. Therefore, experiments were performed in a JSR at atmospheric pressure for various equivalence ratios (0.1-2), for several initial concentrations of NH 3 and NO, at fixed residence times and variable temperature. Kinetic modeling was used to interpret the results and delineate reaction pathways.
Complete list of metadatas

Cited literature [26 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-02271596
Contributor : Philippe Dagaut <>
Submitted on : Tuesday, August 27, 2019 - 9:46:19 AM
Last modification on : Thursday, August 29, 2019 - 1:19:58 AM
Long-term archiving on: Saturday, January 11, 2020 - 2:29:30 AM

File

MCS11-dagaut_2.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : hal-02271596, version 1

Collections

Citation

P. Dagaut. MUTUAL SENSITIZATION OF THE OXIDATION NO AND AMMONIA: EXPERIMENTAL AND KINETIC MODELING. 11th Mediterranean Combustion Symposium, Combustion Institute, Jun 2019, Tenerife, Spain. ⟨hal-02271596⟩

Share

Metrics

Record views

96

Files downloads

47