Ammonia is considered a promising option for achieving carbon neutrality in thermal power generation facilities. However, due to its poor combustibility and concerns about the emission of nitrogen oxides (NOx), which are atmospheric pollutants, as well as the generation of nitrous oxide (N₂O), a greenhouse gas, a major technical challenge is how to reduce these emissions while ensuring stable combustion.

IHI has focused on the potential of ammonia as a fuel since the early 2010s and have been developing technologies to address these challenges. With support from the government, we conducted research and development, leading to a significant turning point when studies showed that NOx emissions could be suppressed even in boilers. This led to the decision to rapidly pursue commercialization using the world’s largest power generation facility (1,000 MW) at JERA’s Hekinan Thermal Power Station (hereafter referred to as Hekinan P/S).

As a step toward commercialization, a demonstration test on an actual unit was necessary, and this was conducted at Unit 4 of Hekinan P/S. The purpose of the demonstration test was to identify challenges for social implementation by examining various characteristics and constraints of the plant during 20% ammonia combustion operation, and to establish ammonia combustion technology based on these findings. The equipment modifications necessary for the demonstration test were realized by installing only the ammonia nozzles and related piping in the case of Unit 4 of Hekinan P/S, based on prior studies. There were no modifications made to the boiler itself, the flue gas and air ducts, or the environmental facilities.

On the other hand, since ammonia had never been used as a fuel in thermal power plants and there were no prior examples, both JERA and IHI took special care to ensure safety. We paid close attention for the equipment specifications and operational procedures to ensure their suitability before conducting demonstration tests, which were carried out without any accidents or incidents. As a result, they successfully achieved the predetermined targets for plant performance, including combustion performance, and completed the project successfully. Furthermore, at Unit 4 of Hekinan P/S, JERA aims to commence commercial operations in the latter half of the 2020s, with 20% of the fuel converted to ammonia.

The results of this demonstration test have attracted worldwide attention. Since introducing ammonia at approximately a 20% ratio can achieve the maximum CO₂ reduction at the fastest and lowest cost, the success of this demonstration test is a groundbreaking achievement. It marks the starting point for expanding fuel conversion at the Hekinan P/S and deployment to other power stations, and it is expected to rapidly advance the social implementation of ammonia．

Ryo Hanaoka
Member，Life Cycle Management Dept., Carbon Solution SBU, IHI Corporation（1-1，Toyosu 3-chome, Koto-ku, Tokyo 135-8710）

Ryo Nakazawa
Member，Life Cycle Management Dept., Carbon Solution SBU, IHI Corporation（1-1，Toyosu 3-chome, Koto-ku, Tokyo 135-8710）

Hiroki Ishii
Member，Life Cycle Management Dept., Carbon Solution SBU, IHI Corporation（1-1，Toyosu 3-chome, Koto-ku, Tokyo 135-8710）

Ryosuke Mizutani
Decarbonization Engineering Unit, Decarbonization Engineering Gr., O&M Engineering Strategy Div., JERA Co., Inc.（1-1-1 Meieki, Nakamura-ku, Nagoya-shi, Aichi, 450-6318）

Hiroyoshi Oshima
Decarbonization Engineering Unit, Decarbonization Engineering Gr., O&M Engineering Strategy Div., JERA Co., Inc.（1-1-1 Meieki, Nakamura-ku, Nagoya-shi, Aichi, 450-6318）