Paper

Duiker Combustion Engineers BV Stoichiometry-Controlled Oxidation (SCO) Technology for Industrial Ammonia Combustion

In recent years, the stoichiometry-controlled oxidation (SCO) concept has been developed by Duiker Combustion Engineers to handle the ammonia-rich streams from sulphur recovery units within refineries. These ammonia rich streams are considered as waste streams that need to be destroyed with low NOx emissions. Several full-scale commercial SCO units have already been designed, delivered, installed and put in operation on refinery sites across the world, firing pure ammonia or rich ammonia-containing flows. The SCO technology has been based upon staged combustion and turns out to be a robust process, which is easy to operate and responds fast to upset conditions.…

Paper

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…

Paper

Experimental and Computational Study for Reduction of NOx Emissions in the Ammonia / Methane Co-Combustion in a 10 KW Furnace

There are severe issues on increasing amount of carbon dioxide (CO2) emission in the world. Many studies are devoted to alternative fuels. One of promising candidates is the utilization of ammonia which is zero emission of CO2, a hydrogen energy carrier, and also can be burned directly as a fuel. For direct combustion of ammonia in industrial furnaces, there were two issues which were weaker radiative heat flux and a huge amount of NOx emission compared with the combustion of methane. We already have reported [1] the solution of the former issue by using the oxygen enriched combustion. The objective…

Paper

Optimization of the NOx Reduction Condition in the Combustion Furnace for the Combustion of “Heavy-Oil – NH3 System” Using CFD

In late years the discharge of the CO2 became the very big problem. The combustion of the fossil fuel in particular exhausts much CO2. Our project team (SIP) is intended to reduce CO2 by using NH3 (10%~30%) in substitution for heavy oil. The ‘SIP energy carriers’ was launched in 2014 (SIP: Strategic Innovation Promotion Program). Ammonia direct combustion team was formed. We conducted a co-research program with Osaka University in this project. We performed experiment of heavy oil – NH3 mixed combustion in the 10kW furnace. As the results, we obtained much experimental data. When we were combusted NH3 and…

Paper

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…

Paper

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…

Paper

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…

Paper

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…

Paper

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…

Paper

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…