Mitsui Chemicals and Maruzen Petrochemical, supported by NEDO (New Energy and Industrial Technology Development Organization, 일본 신에너지산업기술종합개발기구)’s Green Innovation Fund, announced on September 17, 2026 that a demonstration project co-firing ammonia in a naphtha cracking furnace, jointly conducted with Toyo Engineering and Sojitz Machinery, achieved an 85% ammonia co-firing rate based on total heat input in a test furnace. The companies stated this represents a world-leading level for naphtha cracking furnace ammonia co-firing technology compared to publicly available information as of August 2026. The hearth burner has already achieved 100% ammonia firing, while ammonia application to the wall burner is planned for the future.
The demonstration project is part of NEDO’s Green Innovation Fund program under the theme “Development of Manufacturing Technology for Plastic Raw Materials Utilizing CO2, etc.” Mitsui Chemicals and Maruzen Petrochemical serve as the project entities, with Toyo Engineering and Sojitz Machinery participating to jointly develop new dedicated ammonia burners for naphtha cracking furnaces. A naphtha cracking furnace consists of hearth burners installed at the bottom of the furnace and wall burners installed on the furnace side walls; in this demonstration, full ammonia firing was first applied to the hearth burner, while the wall burner has not yet been converted to ammonia. Naphtha cracking furnaces have conventionally used city gas or by-product gas as fuel, and this demonstration aims to reduce carbon dioxide emissions by replacing that fuel with carbon-free ammonia.
The ammonia co-firing rate based on total heat input in the test furnace reached 85%, described as a world-leading level for naphtha cracking furnaces compared to publicly available information as of August 2026. The hearth burner alone has already demonstrated 100% ammonia firing, and nitrogen oxide (NOx) emissions during this process were confirmed to remain at levels equivalent to existing commercial furnaces. The project is scheduled to run from 2021 to 2030, with the ultimate goal of achieving 100% ammonia firing across the entire furnace.
Naphtha cracking furnaces have long been regarded as major sources of carbon dioxide emissions in petrochemical complexes due to their combustion of large volumes of fossil fuel, and this demonstration is significant in that it attempts to decarbonize the petrochemical basic feedstock production process itself using carbon-free ammonia as fuel.
Ammonia co-firing technology for naphtha cracking furnaces remains at an early demonstration stage globally, and achieving 100% firing at the hearth burner while raising the overall furnace co-firing rate to 85% of total heat input is an uncommon accomplishment. As the petrochemical industry has tended to focus more on feedstock diversification and recycled plastics utilization than on decarbonizing the cracker itself, this demonstration highlights the technical potential of retrofitting the combustion process directly. Maintaining NOx emissions at existing commercial furnace levels while achieving a high co-firing ratio suggests that dedicated ammonia firing burner technology is advancing toward a level applicable to actual commercial facilities. Engineering firms and equipment suppliers that developed the burners for naphtha cracking furnaces could gain an advantage in securing related technology and track records if demand for similar decarbonization retrofits expands going forward. However, achieving 100% firing across the entire furnace, including the wall burner, remains an unmet target, meaning further technology development and verification will be needed before commercialization.
Technology development for the wall burner, which has not yet been converted to ammonia, and the timing of its application are the first points to watch. How a phased plan for raising the co-firing rate will be presented on the path toward the 2030 goal of 100% ammonia firing across the entire furnace is another point of interest. In addition, it remains to be seen how the equipment retrofit costs and ammonia supply chain arrangements needed to apply the results of this demonstration to actual commercial naphtha cracking furnaces will be worked out. Whether NEDO’s Green Innovation Fund will announce additional similar petrochemical decarbonization demonstration projects is also worth watching.