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…


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…


Basic Co-Firing Characteristics of Ammonia with Pulverized Coal in a Single Burner Test Furnace

Ammonia is expected as a potential fuel to substitute fossil fuels, because it does not discharge carbon dioxide and is easily handled by liquefaction. There are several ways for the direct use of ammonia as a fuel; for example, use in fuel cells and combustion devices. One of the possible application is the combustion use in thermal power plants. In particular, co-firing of ammonia in coal-fired power plants seems to have a relatively great advantage on the suppression of greenhouse gases, because coal is one of the main emission source of carbon dioxide. On the other hand, it is concerned…


NH3 / N2 / O2 Non-Premixed Flame in a 10 kW Experimental Furnace – Characteristics of Radiative Heat Transfer

There are severe issues on increasing amount of carbon dioxide (CO2) emission in the world. Many studies are devoted on alternative fuels. One of superior candidates is the utilization of hydrogen energy which can realize a low-carbon and hydrogen-based society. Ammonia might play an important role which is zero emission of CO2, and is useful for hydrogen energy carrier as a clean energy. Additionally, ammonia is an easily-liquefiable fuel with pressure of about 0.86 MPa and temperature of 293 K. Commercially, ammonia is produced in large quantity by the Haber–Bosch process. It is also to be produced by using catalyst…


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…


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…


Development of New Combustion Strategy for Internal Combustion Engine Fueled By Pure Ammonia

Ammonia is considered as a promising hydrogen-carrier with good storability and transportability, which, then, can be used as a carbon-free fuel as needed. However, once the ammonia is produced from the regenerative sources, it is essential to develop the energy conversion device of the chemical energy stored in ammonia into some other useful forms, e.g. electricity. Among various candidates, we focus on an internal combustion engine as energy conversion device which can be applied on automobile, power plant and etc. and can use ammonia as fuel only by simple modification. There have been many studies on the use of ammonia…


SIP “Energy Carriers” video: ammonia turbines, industrial furnaces, fuel cells

To demonstrate the progress of the SIP "Energy Carriers" program, the Japan Science and Technology Agency last week released a video, embedded below, that shows three of its ammonia fuel research and development projects in operation. R&D is often an abstract idea: this video shows what it looks like to generate power from ammonia. As it turns out, fuel cells aren't hugely photogenic. Nonetheless, if a picture is worth a thousand words, this will be a long article.