4.6 Article

Evaluation, Reduction, and Validation of a New Skeletal Mechanism for the Cofiring of NH3 and CH4

Related references

Note: Only part of the references are listed.
Article Thermodynamics

A novel object-oriented directed path screening method for reduction of detailed chemical kinetic mechanism

Wei Li et al.

Summary: Numerical simulation is widely used for developing efficient combustors, but the growing size of chemical kinetic mechanisms increases computation costs. This study proposes an object-oriented directed path screening (OoDPS) method to reduce the size of the mechanism while maintaining accuracy. The OoDPS method demonstrates better performance in predicting combustion characteristics compared to other methods.

COMBUSTION AND FLAME (2023)

Article Energy & Fuels

Chemical mechanism of ammonia-methanol combustion and chemical reaction kinetics analysis for different methanol blends

Mingfei Lu et al.

Summary: Ammonia is considered as an attractive alternative fuel for internal combustion engines, but has issues of high ignition temperature and NOx emissions. Blending ammonia with methanol can solve the problems, but there are few studies on the combustion mechanism of this dual fuel. This paper developed a chemical reaction mechanism for ammonia-methanol blends and studied its effects on combustion and emissions.
Article Thermodynamics

An experimental and kinetic modeling study on NH3/air, NH3/H2/air, NH3/CO/air, and NH3/CH4/air premixed laminar flames at elevated temperature

Shangkun Zhou et al.

Summary: Ammonia combustion is important for the off-site use of renewable energy. The combustion characteristics of ammonia with different fuel mixtures were studied, and it was found that the combustion velocity and temperature dependence vary. This research is significant for improving the efficiency of ammonia combustion and reducing nitrogen oxide emissions.

COMBUSTION AND FLAME (2023)

Article Thermodynamics

An experimental and kinetic modeling study on the low and intermediate temperatures oxidation of NH3/O2/Ar, NH3/H2/O2/Ar, NH3/CO/O2/Ar, and NH3/CH4/O2/Ar mixtures in a jet-stirred reactor

Shangkun Zhou et al.

Summary: The oxidation of neat NH3 and co-oxidation of NH3 with H2/CO/CH4 were investigated experimentally and numerically. Results showed that H2 can promote NH3 reactivity below 950 K, while CO/CH4 can promote it below 1175 K. HO2 radical was found to be an important intermediate for NH3 oxidation. As temperature increased, the oxidation of NH3 was dominated by independent interactions between fuels and H/OH/O radicals. In stoichiometric conditions, NO formation mainly depended on NH radicals, while in lean conditions, it depended on the conversion of NH2 to NO through HNO intermediate.

COMBUSTION AND FLAME (2023)

Article Energy & Fuels

Visualization investigation of jet ignition ammonia-methanol by an ignition chamber fueled H2

Fuxing Wei et al.

Summary: Blending ammonia with high-activity fuels and utilizing high-energy ignition can accelerate ammonia combustion. The jet-controlled compound ignition (JCCI) using an ignition chamber fueled by H2 was proposed in this study. By using JCCI, a combustion duration of 85 ms was achieved under an equivalent ratio of 1.0, which is 47.7% shorter than spark ignition (SI). Furthermore, JCCI showed excellent lean burn performance and the combustion duration was reduced by up to 52.2% compared to SI ignition.
Article Thermodynamics

An experimental and modeling study of ammonia oxidation in a jet stirred reactor

Ruoyue Tang et al.

Summary: This study investigates the oxidation of ammonia and proposes a chemical kinetic model for ammonia oxidation. The results show that ammonia oxidation is highly reactive under ultralean conditions, with lower temperatures and higher rates of oxidation. However, this reactivity diminishes rapidly with an increase in equivalence ratio, resulting in similar ammonia oxidation characteristics at equivalence ratios of 0.5 and 1.0. The study also analyzes the reaction pathways for different equivalence ratios and oxidation temperatures.

COMBUSTION AND FLAME (2022)

Article Thermodynamics

Ammonia/Methane combustion: Stability and NOx emissions

Giovanni Battista Ariemma et al.

Summary: Ammonia is considered a valuable energy vector in the shift towards Renewable Energy Sources. This study investigates the combustion characteristics of ammonia/methane blends under MILD Combustion conditions, revealing that the use of blends expands the operational range of the system but leads to higher NOx emissions.

COMBUSTION AND FLAME (2022)

Article Chemistry, Physical

Experimental study and kinetic modeling of NH3/CH4 co-oxidation in a jet-stirred reactor

Shaocai Jin et al.

Summary: This study reports on the experimental and kinetic modeling investigation of the co-oxidation behavior of NH3/CH4 binary fuel in a jet-stirred reactor. The experimental results reveal that NH3 tends to suppress CH4 oxidation in fuel-lean conditions, but no such effect is observed in stoichiometric and fuel-rich conditions. Kinetic modeling shows that the currently existing reaction mechanisms underestimate NO emissions in the low-intermediate temperature range, indicating the need for further optimization.

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY (2022)

Article Thermodynamics

Influence of water addition on MILD ammonia combustion performances and emissions

G. B. Ariemma et al.

Summary: The use of ammonia as an alternative energy carrier poses challenges related to combustion stability and NOx emissions. New combustion modes like MILD Combustion and strategies like water addition to reactants have been explored to address these challenges and improve combustion performance.

PROCEEDINGS OF THE COMBUSTION INSTITUTE (2021)

Article Thermodynamics

An experimental and modeling study of ammonia with enriched oxygen content and ammonia/hydrogen laminar flame speed at elevated pressure and temperature

Krishna Prasad Shrestha et al.

Summary: This study experimentally investigated the laminar flame speeds of ammonia and ammonia-hydrogen blends under different temperature, pressure, and oxygen content conditions, and developed a new kinetic model for predicting the oxidation mechanisms, considering the formation and reduction of nitrogen oxides. The results showed that the laminar flame speed increases with increasing initial temperature, fuel hydrogen content, or oxidizer oxygen content, but decreases with increasing initial pressure. The proposed kinetic model predicts the same trends as experiments and highlights the importance of N2H2 formation under rich conditions.

PROCEEDINGS OF THE COMBUSTION INSTITUTE (2021)

Article Thermodynamics

Ammonia-methane interaction in jet-stirred and flow reactors: An experimental and kinetic modeling study

Suphaporn Arunthanayothin et al.

Summary: Experimental and numerical studies investigated the influence of ammonia addition on methane oxidation, showing that NH3 promoted CH4 reactivity at temperatures below 1200K but had less impact at higher temperatures. A kinetic model helped explain the underlying causes of methane reactivity at low temperatures and the significant role of NOx. The reactivity at higher temperatures was mainly governed by H-abstractions on both fuels.

PROCEEDINGS OF THE COMBUSTION INSTITUTE (2021)

Article Thermodynamics

Combustion chemistry of ammonia/hydrogen mixtures: Jet-stirred reactor measurements and comprehensive kinetic modeling

Xiaoyuan Zhang et al.

Summary: This study investigates the oxidation of ammonia/hydrogen mixtures at intermediate temperatures using experimental and modeling approaches. The results show that hydrogen blending enhances the oxidation reactivity of ammonia, leading to increased OH radical production and accelerated ammonia consumption. Non-monotonous trends in NOx formation are observed at 99% conversion of ammonia, influenced by the competition between dilution and chemical effects of hydrogen addition.

COMBUSTION AND FLAME (2021)

Article Thermodynamics

Experimental and kinetic modeling study on NH3/syngas/air and NH3/bio-syngas/air premixed laminar flames at elevated temperature

Shangkun Zhou et al.

Summary: Ammonia (NH3) plays a crucial role in large-scale storage and long-distance transportation of renewable energy. Co-firing with syngas and bio-syngas, along with increasing the initial temperature of reactants, are effective methods to enhance the reactivity of NH3 flames. However, current kinetic models lack accuracy in temperature dependence, indicating a need for further research in this area.

COMBUSTION AND FLAME (2021)

Review Energy & Fuels

Review on Ammonia as a Potential Fuel: From Synthesis to Economics

A. Valera-Medina et al.

Summary: Ammonia as a fuel vector has been gaining interest and efforts are being made to find new methods to reduce carbon emissions. The current need to decarbonize the economy makes ammonia a viable fuel option, with economic implications being significant.

ENERGY & FUELS (2021)

Article Energy & Fuels

Effect of hydrogen blending on the high temperature auto-ignition of ammonia at elevated pressure

Jundie Chen et al.

Summary: The study found that the addition of hydrogen can nonlinearly reduce the ignition delay time of ammonia and promote further chain branching reactions.
Article Thermodynamics

A functional-group-based approach to modeling real-fuel combustion chemistry - II: Kinetic model construction and validation

Xiaoyuan Zhang et al.

Summary: The study proposes the FGMech approach for developing surrogate and real-fuel kinetic models, with all parameters derived solely from functional group data. By comparing with experimental data, it is found that FGMech reasonably captures the experimental data, indicating promising potential for modeling fuel combustion behavior.

COMBUSTION AND FLAME (2021)

Article Energy & Fuels

An experimental study of laminar ammonia/methane/air premixed flames using expanding spherical flames

Tao Shu et al.

Summary: Experimental investigation of flame properties in ammonia/methane/air mixtures shows significant influence of gas composition and pressure on flame speeds and flammability limits. Linear correlation between flame speed and methane volume fraction is observed, with accurate prediction using Okafor et al. mechanism.
Article Thermodynamics

Autoignition studies of NH3/CH4 mixtures at high pressure

Liming Dai et al.

COMBUSTION AND FLAME (2020)

Review Chemistry, Physical

A Roadmap to the Ammonia Economy

Douglas R. MacFarlane et al.

JOULE (2020)

Article Thermodynamics

Exploration on laminar flame propagation of ammonia and syngas mixtures up to 10 atm

Bowen Mei et al.

COMBUSTION AND FLAME (2020)

Article Chemistry, Multidisciplinary

An experimental, theoretical and kinetic-modeling study of the gas-phase oxidation of ammonia

Alessandro Stagni et al.

REACTION CHEMISTRY & ENGINEERING (2020)

Article Thermodynamics

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

B. Shu et al.

PROCEEDINGS OF THE COMBUSTION INSTITUTE (2019)

Review Thermodynamics

Science and technology of ammonia combustion

Hideaki Kobayashi et al.

PROCEEDINGS OF THE COMBUSTION INSTITUTE (2019)

Article Thermodynamics

Experimental and numerical study of the laminar burning velocity of CH4-NH3-air premixed flames

Ekenechukwu C. Okafor et al.

COMBUSTION AND FLAME (2018)

Review Thermodynamics

Modeling nitrogen chemistry in combustion

Peter Glarborg et al.

PROGRESS IN ENERGY AND COMBUSTION SCIENCE (2018)

Review Thermodynamics

Ammonia for power

A. Valera-Medina et al.

PROGRESS IN ENERGY AND COMBUSTION SCIENCE (2018)

Article Thermodynamics

Comparison of the performance of several recent syngas combustion mechanisms

Carsten Olm et al.

COMBUSTION AND FLAME (2015)

Article Thermodynamics

Shock-tube study of the ignition of multi-component syngas mixtures with and without ammonia impurities

O. Mathieu et al.

PROCEEDINGS OF THE COMBUSTION INSTITUTE (2013)

Article Thermodynamics

An efficient error-propagation-based reduction method for large chemical kinetic mechanisms

P. Pepiot-Desjardins et al.

COMBUSTION AND FLAME (2008)

Article Thermodynamics

A directed relation graph method for mechanism reduction

TF Lu et al.

PROCEEDINGS OF THE COMBUSTION INSTITUTE (2005)