Standards Development

Scope

This document stipulates guidelines for manufacturers of ammonia-fired boilers regarding tests performed from the time of design to acceptance, in order to meet the required environmental performance.

Functional test at test facilities and on-site acceptance tests are required to be carried out for a fuel ammonia-fired boiler. The attached document stipulates the test methods, the measurement items, the evaluation methods, and the test reports for each test.

NOx, NH3, and N2O are measured at the combustion chamber outlet during the functional test and at the boiler outlet during the acceptance test, respectively.

The scope of the attached document is such equipment that satisfies all of the following.

a) Land boilers used for power generation with a power output of 100 MW or more;

b) Use ammonia as fuel;

c) Boiler with burners for combustion of main fuel.

The attached document does not apply to heat recovery steam generators for gas turbines equipped with ammonia duct burners.

Purpose

Background / Foreword

This proposal is made in accordance with Resolution 2022/05 and Resolution 2022/07, which suggests ammonia as one of the target materials of ISO/TC 67. The presentation "Advancing Carbon Neutrality Through International Standardization of Fuel Ammonia" (made at the Haag meeting) is available as N 2105, and more simplified supplementary is attached to this proposal as an annex.

Ammonia has been identified as a decarbonized fuel with the potential contribute to transition to a carbon neutral society. As one of the largest emitters of CO2, the priority should be to apply decarbonized fuel technology to boilers. This will in turn activate the Fuel Ammonia value chain due to the subsequent generation of demand for large amounts of Ammonia.

Benefits of Ammonia

In recent years, ammonia, as well as hydrogen, have attracted attention as decarbonized fuels. In the case of ammonia, this is because ammonia does not generate CO2 during combustion process.

In addition, the technology for the liquefication, transportation and storage of ammonia has safe track record, with the robust infrastructure for applications such as fertilizer and industrial materials. By utilizing and expanding upon current infrastructure this can lead to reduced levels capital expenditure, a lower carbon footprint than having to building new infrastructure from scratch, and faster market application of decarbonized fuel.

Application and Target

There are many potential applications of fuel ammonia, such as boilers for power utility / industrial boilers, gas turbines, marine engines, industrial furnaces, etc. However, from the perspective of achieving carbon net zero, it is necessary to accelerate the application of fuel ammonia to boilers that generate particularly high amounts of greenhouse gasses (“GHG”).

Technical Challenges of Fuel Ammonia

Ammonia is a flammable material and can be handled in the same way as hydrocarbon fuels that have been conventionally used. However, when used as a fuel for combustion, there are two key differences that must be considered and controlled to ensure safe and successful application.

The first key difference is that the combustion rate of ammonia is slower than that of hydrocarbon fuels, and that nitrogen is contained in ammonia molecules. Therefore, it is necessary to combust fuel  ammonia through an appropriate method and equipment shall be installed. Otherwise, there is a risk that unburned ammonia might remain or that nitrogen oxides (i.e. NOx), such as dinitrogen monoxide (N2O), might be increased.

The second key difference is that ammonia is toxic and is the causative agent of odor and PM2.5. Further the presence of nitrogen in ammonia also has to be addressed when fuel ammonia is combusted. Nitrogen monoxide (NO) and nitrogen dioxide (NO2) are the causative agents of acid rain and photochemical oxidants. Moreover, N2O is a potent greenhouse gas approximately 300 times more powerful than that of CO2. Therefore, it is necessary to establish appropriate methods for safely handling and combusting ammonia, so that the emission of these gaseous components can be properly suppressed. Equipment that suppresses nitrogen oxides such as denitrification equipment is already used in some facilities, but there are also power generation and industrial boilers that do not have denitrification facilities or are difficult to reinforce. Therefore, when fuel ammonia is applied to boilers, it is necessary to suppress these gas components to an appropriate level based on the combustion chamber outlet.

To date, research and development on ammonia combustion has been conducted in Japan and other countries to attempt energy transition. The latest results in boilers have shown that by using appropriate combustion methods in burners and combustion chambers, the above combustion emissions for NO and NO2 can be controlled within the acceptable range. It should be noted that for the suppression of combustion emissions in fuel burners, regulations can be found in ISO 22967, Forced draught gas burners, but there are currently no regulations for ammonia, including ISO standards.

Necessity of Standard to cover Fuel Ammonia combustion / Conclusion

Therefore, in order to contribute to GHG reduction at an early stage by using decarbonized fuel ammonia, in power generation and industrial boilers without adversely affecting the environment, it is necessary to provide guidelines for environmental performance testing, which is the responsibility of the manufacturer performing the test.

The proposed provisions will not only contribute to increasing social acceptance of the use of ammonia by power generation companies, but will also contribute to the expansion of ammonia related businesses by promoting the use of ammonia, ultimately contributing to the early realization of carbon neutral society