Global First: JERA, IHI Launch Testing of Fuel Ammonia at Coal Power Plant

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Japanese firms JERA and IHI Corp. have launched the world’s first large-volume fuel ammonia demonstration testing at JERA’s 1-GW Unit 4 of its 4.1-GW Hekinan Thermal Power Station in Aichi Prefecture, Japan. The demonstration testing, which kicked off on April 1 and is slated to continue through June 2024, involves substituting 20% of Hekinan 4’s heating value with fuel ammonia. The project is an integral part of a four-year effort that began in July 2021, subsidized by Japan’s New Energy and Industrial Technology Development Organization (NEDO) to establish ammonia co-firing at a large-scale commercial coal power plant. The demonstration testing seeks to evaluate “both boiler heat absorption and environmental impact characteristics such as exhaust gases,” JERA said. Specifically, it will look at “characteristics of the plant overall, investigating nitrogen oxide (NOx) emissions and confirming factors such as operability and the impact on boilers and ancillary equipment,” JERA said.

1. JERA’s Hekinan Thermal Power Plant in Hekinan City, Aichi Prefecture, is one of Japan’s largest coal-fired power plants. The plant’s Unit 4 in 2024 kicked off demonstration testing aimed at establishing technology to convert 20% of its fuel from coal to ammonia. Courtesy: JERA

If the demonstration testing is successful, JERA—a joint venture between Tokyo Electric Power Co. (TEPCO) and Chubu Electric—plans to commercially operate Hekinan 4 (Figure 1) with ammonia substituting 20% of its heating value. IHI, meanwhile, plans to apply its learnings from the testing demonstration to establish a technology for high-ratio combustion of 50% ammonia or more at thermal plants, as well as further its development of burners for 100% ammonia combustion. These advancements could be deployed at “other thermal power plants in Japan and overseas,” it said.

Advancing Decarbonization in Countries That Need Thermal Power

The NEDO project is especially significant because “it may offer a low-cost first step to quickly advance the decarbonization in countries like Japan that need thermal power generation as an adjustable power source to ensure a stable supply of energy,” JERA and IHI noted. According to the companies, ammonia is an especially promising fuel for coal substitution, given that it emits no greenhouse gases when burned (the combustion reaction formula of ammonia is 4NH3 + 3O2 → 2N2 + 6H2O). While hydrogen offers similar benefits, it has a low transport efficiency owing to its low combustion calorific value per unit volume, and because hydrogen has a low density, it requires much energy for liquefaction. Ammonia can be liquefied at –33.4C, and it is already widely commercially available for uses such as fertilizer production, with infrastructure built out to support its production, storage, transportation, and handling. “Furthermore, since ammonia and coal have similar combustion speeds, they burn well together, so replacing coal with ammonia can reduce CO2 emissions while maintaining the same amount of power generation,” JERA noted in April. In addition, “since this initiative can be carried out while using current equipment, it can be carried out quickly and at low cost. The ratio of fuel ammonia will then be increased step by step, with the ultimate goal of generating electricity using only ammonia.” The two companies underscore that ammonia firing is a critical pathway to decarbonize Japan’s coal fleet as part of the country’s goal to become carbon-neutral by 2050. JERA, notably, is also targeting achieving zero-carbon emissions across its thermal heavy operations by 2050. The company’s plans rely heavily on ammonia and hydrogen demonstrations. It has previously said that it plans to conduct large-scale demonstration tests to increase its ammonia co-firing ratio for coal generation to more than 50% by fiscal year 2028 and aims for commercial operation at a high ratio of over 50% in the first half of the 2030s. JERA is in tandem exploring testing hydrogen combustion at 30% (by volume) at a gas turbine liquefied natural gas (LNG) plant by 2025. These efforts “go hand in hand with increased investment in renewable energy sources like offshore wind power,” it says.