Oxidizer effects on ammonia combustion using a generated non-premixed burner

• Published in: International journal of hydrogen energy 2022-03, Vol.47 (24), p.12317-12337
• Main Authors: Ilbas, Mustafa, Kekul, Ozan, Bektas, Abdulkadir, Karyeyen, Serhat
• Format: Article
• Language: English
• Subjects: Ammonia; CFD; Combustion; Oxy-enrichment
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2021.05.105

In the present study, the pure ammonia combustion in a model combustor is performed to seek ammonia-fueled applications. To this aim, effects of the oxygen enrichment with an oxygen concentration of 100% in the oxidizer on flame characteristics, temperature profiles and NO profiles during the ammonia combustion were evaluated in terms of excess air/oxygen coefficients. Furthermore, in order to better understand the effect of an oxygen of 100% usage under the oxy-ammonia combustion conditions, the air-ammonia combustion has been studied as well and their results are compared and discussed each other. According to the results predicted, the oxidizer with an oxygen content of %100 provides better flame stability in the case of pure ammonia combustion. The most stable flame for oxy-ammonia combustion can be achieved when the excess oxygen coefficient is 1.0 or 1.2. Furthermore, the minimum NO levels emerge under the fuel-rich condition. Temperature and NO emissions decrease considerably under the air-ammonia combustion. However, except the fuel-rich conditions, flame stabilities are not satisfactory due to ammonia's flame speed under the air-ammonia combustion. Moreover, the air-ammonia combustion under the fuel-rich condition seems as a good option for obtaining the lowest NO levels. On the other hand, the oxy-enrichment condition is thought as a promising method for pure ammonia combustion provided that NO emissions should be optimized by using NO reduction methods. •Oxy- and air-ammonia combustion have been taken place.•Temperature and NOX values have been demonstrated.•Equivalence ratio effect on the flame has been studied.•It is revealed that oxy-ammonia combustion performance is favorable.•NOX values are more favorable for air-ammonia than oxy-.