Japan held its third International Conference on Fuel Ammonia in April 2024 as part of a clean energy series. Industrial ministry officials, the International Energy Agency, Mitsubishi Corp., and Aramco representatives spoke on supply chains and maritime decarbonisation.
The symposium was another proof of Japan’s unshakable commitment to a climate solution critics say is dirty and may not suit the schedule of a rapidly reducing globe.
Through “co-firing,” the government and large corporations want to massively reduce carbon dioxide emissions from coal-fired power plants by substituting a portion of the coal fuel with ammonia. Co-firing ammonia reduces plant emissions because it does not emit CO2. Co-firing a coal plant does not require extensive retrofits, allowing utilities to use their assets.
Japan, like all nations, must decarbonise its energy sector; 27.8% of its energy mix was coal in 2022. The government’s energy plan is to reduce coal’s role to 19% by 2030, despite UN and environmental requests for OECD countries to stop using coal by then. The same energy plan predicts ammonia and hydrogen will supply 1% of Japan’s energy by 2030.
Though expensive, burning ammonia for power is technically viable but not frequently used. Japanese utility JERA is testing a 20:80 ammonia-to-coal co-firing ratio at its Hekinan Thermal Power Station in Aichi Prefecture in 2024.
The government’s transition roadmap calls for dedicated combustion or co-firing with carbon capture and storage (CCS) technology by 2050, while JERA aims to gradually increase co-firing to 100% ammonia combustion.
As the government and companies hurry to develop supply networks to feed them fuel ammonia from around the world, climate policy and air pollution experts wonder whether ammonia is a clean fuel that can help Japan decarbonise.
Their environmental concerns are dual. First, ammonia production emits a lot of CO2, therefore substituting coal with it may not reduce CO2 emissions. Second, air pollution from the ammonia supply chain could harm persons and ecosystems.
CO2 Cuts Uncertain
Although burned, ammonia doesn’t emit CO2, yet its manufacturing demands a lot of energy. The ammonia industry emits 1.3% of global CO2.
Experts classify ammonia by CO2 emissions using colours. The three main kinds of ammonia are “grey” ammonia made from fossil fuels, such as natural gas, “blue” ammonia with 80–90% of CO2 emissions absorbed using CCS technology, and “green” ammonia made from renewable energy.
In recent years, the Japanese government and enterprises have launched many fuel ammonia agreements and feasibility studies with foreign partners.
Mitsui, Marubeni, and Japanese utilities are investigating blue ammonia production in Australia. Marubeni also wants a Canadian blue ammonia supply chain.
IHI, Mitsui OSK Lines, and INPEX worked on a UAE blue ammonia production and shipping demonstration project. JERA also collaborated with a UAE state-owned oil and gas business on ammonia. Japanese corporations and the government are supporting a blue ammonia project with Aramco in Saudi Arabia.
Blue ammonia uses CCS technology to reduce CO2 emissions, although CCS is expensive, and rarely used, and many CCS projects have failed.
According to the Japanese think group Climate Integrate, “Even if CCS becomes practical in practice, carbon capture rates would still be around 80% to 85%, which indicates that zero emissions would still not be possible.”
“According to available statistics, most ammonia projects use fossil fuels,” stated Kimiko Hirata, Climate Integrate’s executive director. She thinks CCS is “just an excuse” to keep making ammonia using gas.
Some ammonia projects are green. IHI and a Petronas subsidiary in Malaysia conducted a green ammonia feasibility study, and Sumitomo Corp. is working with a Chilean power producer.
According to Motoichi Kato, deputy secretary-general of the Clean Fuel Ammonia Association (CFAA), which includes almost all of Japan’s major fuel ammonia stakeholders, all of Japan’s ammonia imports are grey because blue and green ammonia are not yet mass-produced.
CCS plant in Fort Saskatchewan, Alberta. Blue ammonia uses CCS technology to reduce CO2 emissions, although CCS is expensive, and rarely used, and many CCS projects have failed.
Kato wrote via email that imported gasoline ammonia will be blue instead of grey by 2027. CFAA roadmaps show green ammonia percentages increasing, but “the ratios for blue and green are flexible, depending on how much each would cost,” he said.
If burned improperly, green ammonia can release N2O, a greenhouse gas. Japanese businessmen want to solve the problem of sluggish, incomplete ammonia combustion, which emits N2O, more potent than CO2.
Supply-Chain Pollution
Experts worry about how to generate and burn so much ammonia, Japan will need 3 million tons by 2030 and 30 million tons by 2050, which could affect air and water quality.
Climate Integrate warns that fixing atmospheric nitrogen to make ammonia may further disrupt nitrogen cycles. Nitrogen increases marine ecosystem eutrophication, air pollution, and groundwater contamination.
Japanese corporations are developing ammonia-fuelled ships to transport their precious cargo to reduce CO2 emissions. Ammonia fuelling ships emit and pose environmental dangers, according to a new Maersk Mc-Kinney Moller Centre for Zero Carbon Shipping research from Denmark.
First, ammonia slip, the deadly release of unburned ammonia into the atmosphere, endangers ship crew, neighbouring people, and transportation routes. Second, nitrogen oxides, air pollutants that harm humans and the environment, would result. Innovation and emission treatment technology can manage pollution, the centre found.
Air pollution from ammonia combustion in Japanese coal plants is a hot topic. The Finnish Centre for Research on Energy and Clean Air (CREA) used data from JERA’s Hekinan plant and other scientific studies to estimate PM2.5 and PM2.5 precursor gases produced from co-firing ammonia.
Even with conservative emissions projections, lifecycle air pollution increased by 67% at a 20% co-firing ratio and 167% at a 50% ratio, with shipping and combustion ammonia gas emissions accounting for most of the increase.
In response to the May 2024 CREA report, JERA stated that “ammonia co-firing does not increase air pollutants.” A 2019 20% ammonia co-firing test at a test facility showed no ammonia emission, supporting the company’s assertions. JERA further indicated that it either entirely consumes unburned ammonia as a pollutant-reducing agent or cleans plant equipment using water.
Jamie Kelly, CREA air quality analyst and report co-author, stated that co-firing air pollution is still harmful even if it stays at the same level as 100% coal-fired power stations. State of Global Air reports that coal-fired power plants provide 12% of Japan’s PM2.5 concentration, which causes 43,000 premature deaths.
Kelly claimed switching to renewable energy will reduce mortality. He said “I do not see these people or these arguments involved” in ammonia as an alternative energy debate, even if specialists on air pollution, health, and ecosystems are aware of its concerns.
Kato of the CFAA said that co-firing technology addresses strict national and municipal environmental regulations, including N2O emissions. On its website, the organisation makes similar claims regarding smokestack emissions but concedes that stray ammonia emissions during manufacture are “unavoidable,” but just 0.001% of emissions.
Foreign Expansion
Japan wants to use fuel ammonia more abroad, especially in Asia. JERA is co-firing feasibility studies with Philippine, Thai, and Malaysian partners. With Indonesian state utility PLN, IHI and Mitsubishi Heavy Industries are reportedly exploring ammonia co-firing.
However, dozens of environmental groups in these nations and internationally oppose ammonia as a transition fuel.
According to data-driven climate policy charity TransitionZero, even a 50% co-firing ratio would hardly bring coal facilities’ CO2 emissions on line with natural gas plants in the region.
Isabella Suarez, an engagement analyst with TransitionZero, said Asian utilities will need to switch from baseload fossil fuels to intermittent renewable energy to fulfil their net zero ambitions.
“It just makes more sense to initiate that shift, rather than hold on to these (fossil fuel) technologies,” she said.
“Once renewable energy makes green ammonia more abundant, fuel ammonia could be useful in hard-to-decarbonise industrial sectors by 2050,” Suarez said.