Nagaoka Methanation Project Injects Synthetic Methane into Gas Grid, Validating CCU at Scale

The Nagaoka Methanation Demonstration Project in Niigata Prefecture achieved a significant operational milestone on February 20, 2026, with the successful injection of synthetic methane, or e-methane, directly into the existing natural gas pipeline network. This event validates a critical step in Carbon Capture and Utilization (CCU) technology, offering a climate-friendlier fuel that integrates seamlessly with current gas infrastructure.

The demonstration facility, located at INPEX Corporation's Koshijihara Plant in Nagaoka City, produces the e-methane by combining captured industrial exhaust carbon dioxide with hydrogen within a specialized methanation reactor. With a design capacity to process approximately 400 normal cubic meters of CO2 per hour, the operation is positioned as one of the world's largest CO2-to-methane conversion setups currently in the demonstration phase. This output is sufficient to supply the annual needs of around 10,000 average households, and recent trials confirmed the technical quality, yielding synthetic gas with a methane concentration of 96%.

This initiative is a collaboration involving INPEX Corporation and Osaka Gas Co., Ltd., supported by a subsidy from the New Energy and Industrial Technology Development Organization (NEDO) secured in 2021. Osaka Gas developed the reaction process technology, while INPEX manages the overall project and operation of the test equipment. Construction commenced in 2023, with the demonstration experiment beginning earlier this year, aligning with Japan's national strategy to achieve net-zero greenhouse gas emissions by 2050.

The successful pipeline injection technically affirms the feasibility of scaling up and integrating carbon-neutral fuel directly into the established grid, thereby maximizing the utility of existing gas mains while pursuing decarbonization goals. Furthermore, the Japan Gas Association has formally recognized the facility as a clean gas production plant, a crucial administrative step enabling the issuance of verifiable environmental certificates for the e-methane produced.

This development offers a pathway to decarbonize sectors reliant on high-temperature heat that are resistant to full electrification. While technical integration is proven, the long-term commercial viability will depend on external factors, primarily the cost associated with procuring low-carbon hydrogen, a necessary reactant. The project is scheduled to conclude in March 2027, which will provide the final data required to determine the definitive pathway toward broader commercialization of this technology.