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Pure Ammonia Combustion Micro Gas Turbine System

To protect against global warming, a massive influx of renewable energy is expected. Although hydrogen is a renewable media, its storage and transportation in large quantity has some problems. Ammonia fuel, however, is a hydrogen energy carrier and carbon-free fuel, and its storage and transportation technology is already established. In the 1960s, development of ammonia combustion gas turbines was abandoned because combustion efficiency was unacceptably low [1]. Recent demand for hydrogen energy carriers has revived the interest in ammonia as fuel [2, 3]. In 2015, ammonia-combustion gas turbine power generation was reported in Japan using a 50-kW class micro gas…

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Performance of Ammonia-Natural Gas Co-Fired Gas Turbine for Power Generation

Ammonia is paid special attention as renewable energy carrier [1-3], because it offers advantages in generation, transportation and utilization. Haber-Bosch method is already established as ammonia generation method; large amount of ammonia is already used as fertilizer and chemical raw material. Ammonia can be liquefied at room temperature. Its transport and storage system are already established. Ammonia is cheaper to transport than hydrogen. Ammonia can be used as carbon-free fuel in internal combustion engines as alternative to conventional hydrocarbon fuels. However, it has different combustion characteristics. For example, the nitrogen atom contained in the ammonia molecule, causes high NOx emission…

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Two Stage Ammonia Combustion in a Gas Turbine like Combustor for Simultaneous NO and Unburnt Ammonia Reductions

Ammonia is expected not only as a hydrogen energy carrier but also as a carbon free fuel. Recently, ammonia fueled gas turbine combustor was successfully demonstrated. However, large amount of NOx was produced when ammonia burns because ammonia includes nitrogen atom in the ammonia molecule. In addition, unburnt ammonia concentration in exhaust gas also needs to be reduced. In this study, we proposed a combustion concept in order to reduce NO and unburnt ammonia concentrations in the exhaust gas simultaneously in a gas turbine like model swirl combustor. In this concept, two stage (rich – lean) combustion was employed. Two…

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Development of Low-NOx Combustor of Micro Gas Turbine Firing Ammonia Gas

A massive influx of renewable energy is required in order to mitigate global warming. Although hydrogen is a renewable media, its storage and transportation in large quantity is difficult. Ammonia, however, is a hydrogen energy carrier, and its storage and transportation technology is already established. Although ammonia fuel combustion was studied in the 1960s in the USA, the development of an ammonia fuel gas turbine had been abandoned because combustion efficiency was unacceptably low [1]. Recent demand for hydrogen energy carrier revives the usage of ammonia fuel. The National Institute of Advanced Industrial Science and Technology (AIST) in Japan, in…

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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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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…

Paper

Development of ammonia / natural gas dual fuel gas turbine combustor

NH3 is a carbon-free fuel, so it has the potential to reduce CO2 emission from the power plant when used as a fuel. However, NH3 has combustion characteristics different from conventional hydrocarbon fuels. The N atom in the ammonia molecule causes high NOx emission through combustion reactions. To develop a gas-turbine combustor, which burns a combination of NH3 and natural gas with controlled emissions, combustion characteristics have been studied experimentally and numerically by using a swirl-burner, which is typically used in gas-turbines. Detailed exhaust gas compositions of the burner have been measured under atmospheric pressure and fuel lean conditions. As…

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Combustion characteristics of ammonia/air flames for a model swirl burner and an actual gas turbine combustor

Ammonia is expected not only as hydrogen energy carrier but also as carbon free fuel. For an industrial use of ammonia combustor, ammonia flame stabilized on a swirl combustor should be clarified. However, in order to realize an ammonia-fueled combustor, there are some issues to be solved, such as a difficulty of flame stabilization and reductions of NOx and ammonia emission. In this study, stabilization and emission characteristics of ammonia / air flames stabilized by a model swirl burner are investigated. The outer and inner diameters of the swirler are 24 mm and 14 mm, respectively, and the swirl number…

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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…