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Methods for Low NOx Combustion in Ammonia / Natural Gas Dual Fuel Gas Turbine Combustor

Ammonia is a carbon-free fuel, so it has potential to reduce carbon dioxide emission from power plants when used as a fuel. However, combustion characteristics of ammonia are notably different from hydrocarbon fuels, especially regarding NOx emission [1]. The nitrogen atom of the ammonia molecule may cause high NOx emission. Therefore, special techniques to reduce NOx emission are essential for gas turbine combustors which burn ammonia and natural gas. The results of our previous study [2] showed the characteristics of NOx emission in single-stage combustion. In this study, the concept for low-emission combustion in two-stage combustion has been examined numerically…

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Efficient and Clean Combustion of Ammonia-Hydrogen-Air Mixtures

Based on its well-known merits ammonia has been gaining special attention as a potential renewable energy carrier which can be replaced in power generation systems. Considering its low flame speed and its potential for producing fuel NOx as the main challenges of combusting ammonia, flame stability, combustion efficiency, and NOx formation are experimentally investigated. Focus is on premixed ammonia-hydrogen-air flames with high mixture fractions of ammonia (60-90% by volume) under standard temperature and pressure conditions. We introduce silicon-carbide (SiC) porous block as a practical and effective medium for ammonia-hydrogen-air flame stabilization which enables stable and efficient combustion of the mixtures…

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Combustion Emissions from NH3 Fuel Gas Turbine Power Generation Demonstrated

To protect against global warming, a massive influx of renewable energy is expected. Although H2 is a renewable media, its storage and transportation in large quantity is difficult. NH3 fuel, however, is an H2 energy carrier and carbon-free fuel, and its storage and transportation technology is already established. Although NH3 fuel combustion was studied in the 1960s in the USA, the development of an NH3 fuel gas turbine had been abandoned because combustion efficiency was unacceptably low [1]. Recent demand for H2 energy carrier revives the usage of NH3 fuel, but no one has attempted an actual design setup for…

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Nitrogen-Based Fuels: Renewable Hydrogen Carriers

Renewable energy sources such as solar and wind suffer from an intermittent power output, making energy storage a key element in future energy infrastructure. Fuels offer both high energy densities and efficient transport compared to other energy storage alternatives. One energy storage solution is water electrolysis. However, the generated hydrogen is incompatible with the global fuel infrastructure, inhibiting its implementation as an energy vector. Storing hydrogen on carrier atoms provides a safe and convenient way to utilize and transport renewable energies. While carbon–based fuels are commonly suggested, using nitrogen as a hydrogen carrier can potentially offer a superior option. In…

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NH3: The Optimal Alternative Fuel

Unlike some technology areas where “all of the above” has significant advantages, there are tremendous advantages associated with choosing a single, optimized, liquid transportation fuel. The cost, efficiency and environmental benefits associated with choosing an optimized liquid transportation fuel are enormous and merit serious consideration. NH3 most closely meets the criteria for an ideal liquid transportation fuel. It is the most efficient and cost-effective means of delivering hydrogen and has an extensive world-wide delivery system already in place. Using currently available catalytic controls, NH3 emissions can be even cleaner than hydrogen engine emissions. While NH3 can effectively be produced using…

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Comprehensive Evaluation of NH3 Production and Utilization Options for Clean Energy Applications

The project proposes a comprehensive investigation on the analysis, assessment and optimization of ammonia synthesis processes under renewable energy portfolio, including low-cost hydro, wind, solar, geothermal, ocean, biomass, etc. Furthermore, ammonia production via hydrocarbon decomposition, which will be investigated in the study, is a promising option to utilize fossil fuels in a cleaner and environmentally benign way. Case studies for various locations and applications in communities, cities and provinces to develop and implement clean solutions are performed. The objectives of this project include energy and exergy analyses, environmental impact assessments, thermo-economic analyses and evaluations, optimization studies, experimental investigation, scalability and…

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Ammonia Renewable Energy Fuel Systems at Continental Scale

We must soon “run the world on renewables” but cannot, and should not try to, accomplish this entirely with electricity transmission. New, abundant, low-cost, unconventional natural gas supplies are finite; burning adds CO2 to Earth’s atmosphere. Humanity’s goal must be nothing less than: Transforming the world’s largest industry from ~80% fossil to ~100% renewable, CO2-emission-free energy sources as quickly as we prudently and profitably can. We should now carefully consider using pipeline networks, rather than the electricity grid, for solving the three salient technical problems of renewable energy (RE) at lower cost: Transmission: from diverse, stranded, remote, rich RE resources…

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Key Life Cycle Assessment Numbers for NH3, Green and Brown Energy

This talk will present the results of two recent studies. In the first study, four different ammonia production methods are comparatively evaluated using life cycle assessment (LCA). The proposed ammonia production systems consist of an electrolyzer for hydrogen production and a Haber-Bosch plant for ammonia synthesis. The required energy for the systems are utilized from various resources namely hydropower, nuclear, biomass and municipal waste. Life cycle assessment methodology is used to identify and quantify environmental impacts in global warming potential, human toxicity and abiotic depletion categories of each method during the life cycle of the systems. The proposed non-conventional ammonia…

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Power Generation and Flame Visualization of Micro Gas Turbine Firing Ammonia or Ammonia-Methane Mixture

A demonstration test with the aim to show the potential of ammonia-fired power plant is planned using a micro gas turbine. 50kW class turbine system firing kerosene is selected as a base model. A standard combustor is replaced to a prototype combustor which enables a bi-fuel supply of kerosene and ammonia gas. Diffusion combustion is employed to the prototype combustor due to its flame stability. 44kW power generation was achieved by 100% heat from ammonia gas. Although NOx concentration in the exhaust gas of ammonia combustion exceeded 500ppm, NOx removal equipment reduced NOx concentration below 10ppm. Over 30kW power generation…

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NOx emission analysis and flame stabilization of ammonia-hydrogen-air premixed flames

Based on its well-known merits, ammonia has been gaining special attention as a potential renewable energy carrier which can be replaced in power generation units. One of the major challenges with ammonia as a fuel is NOx emission, which has a complex underlying chemical kinetics. In an earlier chemical kinetics study by the authors, NOx formation sensitivity was thoroughly studied in a wide range of combustion conditions [Nozari & Karabeyoğlu, J.Fuel 2015]. As the next step, premixed ammonia-hydrogen-air flames are studied experimentally in standard temperature and pressure condition. Effects of some major influential parameters on NOx emission levels are investigated:…