Hydrogen and ammonia as a primary fuel – A critical review of production technologies, diesel engine applications, and challenges

Manigandan, S.; Ryu, Je Ir; kumar, T. Raj; Elgendi, Mahmoud

doi:10.1016/j.fuel.2023.129100

Cited by 53 publications

(6 citation statements)

References 85 publications

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“…Challenges of using ammonia in engines and gas turbines are investigated extensively. − There have been a number of studies on the use of NH 3 as an engine fuel, but its poor combustion characteristics for conventional engine combustion techniques have been difficult to overcome. Hence, additional fuels such as hydrogen, natural gas, or diesel have been suggested as combustion promotors. , In particular hydrogen is interesting as a cofuel, − because it is carbon-free and may possibly be produced from cracking ammonia in a precombustion process.…”

Section: Introductionmentioning

confidence: 99%

Flow Reactor Oxidation of Ammonia–Hydrogen Fuel Mixtures

Alzueta,

Mercader,

Cuoci

et al. 2024

Energy Fuels

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Hydrogen-assisted oxidation of ammonia under flow reactor conditions was investigated through experiments and chemical kinetic modeling. Novel experiments, conducted in a tubular laminar flow reactor as a function of the NH 3 /H 2 ratio, stoichiometry, and temperature (725−1475 K), were analyzed along with literature results from tubular and jet-stirred flow reactors. Ignition and oxidation of NH 3 is strongly promoted by the presence of H 2 under all conditions investigated. In general, the behavior is captured well by the kinetic model. With an increasing fraction of H 2 in the fuel mixture, the generation of chain carriers gradually shifts from being controlled by the amine reaction subset to being dominated by the oxidation chemistry of H 2 , which is known more accurately. However, under reducing conditions, the H 2 consumption rate is strongly underpredicted. This shortcoming suggests that the thermochemistry of amine radicals and/or the formation of higher amines need further assessment. The present analysis shows that for lean oxidation of NH 3 /H 2 mixtures in tubular flow reactors, data obtained at higher temperatures, particularly for NO formation, may be strongly affected by the reaction during preheating or by mixing (dependent on reactor design) in the inlet section prior to the isothermal zone. Modeling predictions for the high pressure, medium-temperature ignition conditions in a large diesel engine indicate that NH 3 /H 2 fuel mixtures may still require a cofuel to secure stable ignition.

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Section: Introductionmentioning

confidence: 99%

Flow Reactor Oxidation of Ammonia–Hydrogen Fuel Mixtures

Alzueta,

Mercader,

Cuoci

et al. 2024

Energy Fuels

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“…To date, the most achievable route for large-scale green ammonia synthesis has been the use of wind, solar, and hydro energy to power electrolytic hydrogen plants. Green hydrogen may replace gray or brown hydrogen in the Haber–Bosch process, with the aim to entirely eliminate unnecessary carbon emissions. , At present, challenges remain for practical industrial applications including the fluctuating supply from renewable energy sources, economic feasibility, and catalytic stability.…”

Section: Introductionmentioning

confidence: 99%

Causality Analysis of the Green Ammonia Synthesis Process Using the Convergent Cross Mapping Algorithm

Yang,

Li,

Zhang

et al. 2024

Ind. Eng. Chem. Res.

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Ammonia synthesis has been gradually altered from the gray process (using fossil fuels as hydrogen sources) to the green process (directly or indirectly using water electrolytic cells as hydrogen sources powered by renewable energy), with the motivation of sustainable development and carbon neutrality. The fluctuating nature of renewable energy and the location mismatch between power plants and the production complex make gray ammonia production roadmaps likely to fail or embrace the change. Establishing knowledge graphs in the form of causal relationship network diagrams will help enterprise decision-makers and engineers better understand the process and generate correct production operations and scheduling. In this study, a chemical engineeringinformed method is introduced to generate causal networks of multiple load conditions for green ammonia production. Expert knowledge of chemical engineering is embedded in the determination of the existence and corresponding time delay of the causal relationships of variable pairs. In an industrial case study, the skeletal knowledge graphs and evolution of the control mechanisms were identified in a comparison of the derived causal networks. Extended applications are expected with further integration of controlling theory and algorithms.

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“…The utilization of NH 3 as a fuel source for engines was already implemented during the 1940s . Presently, the viability of employing NH 3 in fuel cells, gas turbines, and internal combustion engines has been substantiated. ,− …”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Study on the Effects of N₂ and NH₃ in NH₃/Syngas/Air Laminar Premixed Flame

Wen,

Zhu,

Zeng

et al. 2024

Energy Fuels

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Blending syngas with ammonia (NH3) effectively overcomes the high minimum ignition energy and low laminar burning velocity (S L) of NH3, facilitating the realistic application of NH3 as a fuel for gas turbines. Thus, the present study combines experiments and numerical simulations to investigate the impacts of diluent N2 (0–60%) and NH3 (25–50%) on NH3/syngas/air flames. The analysis suggests that increasing N2 and NH3 content, respectively, results in a decrease in the S L of the mixture. At Φ = 1.0, as the N2 content increases from 0 to 60%, the S L of the mixture decreases from 80.1 to 28.3 cm/s. The S L decreases from 80.1 to 36.4 cm/s as the NH3 content increases from 25 to 50%. The increase in N2 content decreases the maximum mole fractions of H, OH, and O radicals, and the net reaction rates of chain reactions also decrease. The net reaction rate of H + O2 = O + OH at Z N2 = 60% decreases by 85.8% compared to 0.018 (mol/cm3 s) at Z N2 = 0% at Φ = 1.0. As NH3 content increases, the impact of chain reactions associated with the NH3 reaction mechanism on the combustion process becomes more pronounced. With the increase in NH3 content, the ratio of chemical effect to physical effect initially increases and then decreases, reaching a maximum value of 25.4% around Z NH3 = 30%. This value is much less than 1, indicating an overall inhibitory effect. The analysis of reaction pathways and NO emissions suggests that the presence of N2 reduces NH3 consumption, which in turn reduces NO generation. The increase in NH3 content promotes the conversion of N2O to N2, simultaneously reducing NO emissions.

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Hydrogen and ammonia as a primary fuel – A critical review of production technologies, diesel engine applications, and challenges

Cited by 53 publications

References 85 publications

Flow Reactor Oxidation of Ammonia–Hydrogen Fuel Mixtures

Flow Reactor Oxidation of Ammonia–Hydrogen Fuel Mixtures

Causality Analysis of the Green Ammonia Synthesis Process Using the Convergent Cross Mapping Algorithm

Experimental and Numerical Study on the Effects of N₂ and NH₃ in NH₃/Syngas/Air Laminar Premixed Flame

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Hydrogen and ammonia as a primary fuel – A critical review of production technologies, diesel engine applications, and challenges

Cited by 53 publications

References 85 publications

Flow Reactor Oxidation of Ammonia–Hydrogen Fuel Mixtures

Flow Reactor Oxidation of Ammonia–Hydrogen Fuel Mixtures

Causality Analysis of the Green Ammonia Synthesis Process Using the Convergent Cross Mapping Algorithm

Experimental and Numerical Study on the Effects of N2 and NH3 in NH3/Syngas/Air Laminar Premixed Flame

Contact Info

Product

Resources

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Experimental and Numerical Study on the Effects of N₂ and NH₃ in NH₃/Syngas/Air Laminar Premixed Flame