Numerical study on effect of oxygen content in combustion air on ammonia combustion

Jun, Li; Huang, Hongyu; Kobayashi, Noriyuki; He, Zhaohong; Osaka, Yugo; Zeng, Tao

doi:10.1016/j.energy.2015.10.060

Cited by 139 publications

(37 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…HNO, which is a significant predecessor for NO formation, also increased at lean conditions, which lead to the increase in NO. At rich conditions, NH 2 , NH, and N radicals reduced the reaction rate of NO decreasing its mole fraction [14].…”

mentioning

confidence: 93%

“…This enhancement was caused by chemical and transport effects [12]. Using CHEMKIN, the same author studied the effect of oxygen enrichment on the combustion characteristics of ammonia [14]. As of the short-lived H, O, and OH radicals, they tended to increase with oxygen-enriched combustion [12,14].…”

mentioning

confidence: 99%

“…Using CHEMKIN, the same author studied the effect of oxygen enrichment on the combustion characteristics of ammonia [14]. As of the short-lived H, O, and OH radicals, they tended to increase with oxygen-enriched combustion [12,14]. HNO, which is a significant predecessor for NO formation, also increased at lean conditions, which lead to the increase in NO.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Algorithmic Analysis of Chemical Dynamics of the Autoignition of NH3–H2O2/Air Mixtures

et al. 2019

View full text Add to dashboard Cite

The dynamics of a homogeneous adiabatic autoignition of an ammonia/air mixture at constant volume was studied, using the algorithmic tools of Computational Singular Perturbation. Since ammonia combustion is characterized by both unrealistically long ignition delays and elevated NO x emissions, the time frame of action of the modes that are responsible for ignition was analyzed by calculating the developing time scales throughout the process and by studying their possible relation to NO x emissions. The reactions that support or oppose the explosive time scale were identified, along with the variables that are related the most to the dynamics that drive the system to an explosion. It is shown that reaction H 2 O 2 (+M) → OH + OH (+M) is the one contributing the most to the time scale that characterizes ignition and that its reactant H 2 O 2 is the species related the most to this time scale. These findings suggested that addition of H 2 O 2 in the initial mixture will influence strongly the evolution of the process. It was shown that ignition of pure ammonia advanced as a slow thermal explosion with very limited chemical runaway. The ignition delay could be reduced by more than two orders of magnitude through H 2 O 2 addition, which causes only a minor increase in NO x emissions.

show abstract

mentioning

confidence: 93%

mentioning

confidence: 99%

See 1 more Smart Citation

Algorithmic Analysis of Chemical Dynamics of the Autoignition of NH3–H2O2/Air Mixtures

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Since the NH4Cl-MH and NH4Cl-MNH2 materials form NH3/H2 gas mixtures during decomposition, the fuel produced could be burnt in an internal combustion engine to avoid poisoning of fuel cell membranes. Generally NH3 has a narrow flammability limit of 15.5% to 27% volume in air, 20 which leads to a low This journal is © The Royal Society of Chemistry 20xx…”

Section: Technological Feasibility Assessmentmentioning

confidence: 99%

“…19 Providing the nitrogen and hydrogen used to synthesise the ammonia are derived from clean and renewable sources, this reaction does not result in the release of hazardous air pollutants such as CO2, SO2 and soot. 20 Generally NH3 has a narrow flammability limit of 15.5% to 27% volume in air, 20 which leads to a low combustion rate. However, recent studies have shown that the presence of hydrogen during ammonia combustion can lower combustion temperatures and increase the burning velocity of ammonia flames.…”

Section: Introductionmentioning

confidence: 99%

Ammonium chloride–metal hydride based reaction cycle for vehicular applications

et al. 2019

View full text Add to dashboard Cite

show abstract

Oxy‐ and air‐ammonia premixed combustion in a two‐inlet cyclone combustor

Bektaş¹

2022

Intl J of Energy Research

View full text Add to dashboard Cite

Summary Many scientists have received significant attention since ammonia comprises a carbon‐free chemical and could be derived from renewable hydrogen and air‐separated nitrogen. Most of them think it could be an alternative fuel rather than methane in a cyclonic burner. The main goal of this study is to investigate the possible ways of using ammonia as a clean and sustainable fuel. For this purpose, we first investigated the premixed oxy‐ammonia combustion behaviour using a two‐inlet cyclone combustor. Then, the findings values are compared with the combustion performance of air‐ammonia and air‐methane combustion. Cyclone combustors provide improved mixing quality and longer combustion residence time. The computational fluid dynamics (CFD) simulation was used in this study to estimate the temperature and emissions levels. The findings demonstrate that the highest predicted temperature values of oxy‐ammonia combustion (1828 K) are higher than air‐methane (1538 K) and air‐ammonia combustion (994 K). In addition, NOx emissions have been predicted by post‐processing the CFD code used in this study. According to predicted NOx levels, oxygen usage as an oxidizer rather than air significantly influences NOx emission levels due to thermal and fuel NOx mechanisms. The NOx levels of stoichiometric combustion are higher than the fuel‐rich combustion in all cases. Besides, the lowest NO emission levels are predicted under fuel‐rich conditions of ammonia at the combustor outlet. It is also determined that while the highest axial velocity values occur in the flame regions, ammonia's highest laminar burning velocity is achieved under the fuel‐rich states with Ø = 1.1 for oxy‐ammonia. Therefore, it is concluded that oxy‐ammonia combustion has a more significant combustion performance than air‐methane combustion with the robust whirling flow, sound mixing, and combustion structure.

show abstract

Numerical study on effect of oxygen content in combustion air on ammonia combustion

Cited by 139 publications

References 30 publications

Algorithmic Analysis of Chemical Dynamics of the Autoignition of NH3–H2O2/Air Mixtures

Algorithmic Analysis of Chemical Dynamics of the Autoignition of NH3–H2O2/Air Mixtures

Ammonium chloride–metal hydride based reaction cycle for vehicular applications

Oxy‐ and air‐ammonia premixed combustion in a two‐inlet cyclone combustor

Contact Info

Product

Resources

About