2018

A shock tube and modeling study on the autoignition properties of ammonia at intermediate temperatures

A shock tube and modeling study on the autoignition properties of ammonia at intermediate temperatures

B. Shu, S. K. Vallabhun, X. He, G. Issayev, K. Moshammer, A. Farooq, R. X. Fernandes

Proceedings of the Combustion Institute, (2018)
B. Shu, S. K. Vallabhun, X. He, G. Issayev, K. Moshammer, A. Farooq, R. X. Fernandes
Ammonia, Shock tubes, Auto-ignition delays, Chemical kinetics, Modeling
2018

Fig: Typical pressure profile (black solid line) and corresponding OH* signal (solid red line) as well as the determination of the ignition delay time (dashed line). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article).
Ammonia (NH3) has been considered as a promising alternative energy carrier for automobile engines and gas turbines due to its production from renewable sources using concepts such as power-to-gas. Knowledge of the combustion characteristics of NH3/air and the formation of pollutants, especially NOx and unburned NH3, at intermediate temperatures is crucially important to investigate. Detailed understanding of ammonia reaction mechanism is still lacking. The present study reports ignition delay times of NH3/air mixtures over a temperature range of 1100–1600 K, pressures of 20 and 40 bar, and equivalence ratios of 0.5, 1.0, and 2.0. The experimental results are compared to the literature mechanism of Mathieu and Petersen (2015) and reasonable agreement is observed. Detailed modeling for ammonia emissions is performed, and the NH3/air combustion is found to be potentially free from NOx and unburned NH3 at fuel-rich conditions.
DOI: 10.1016/j.proci.2018.07.074