INPEX Corporation, Osaka Gas Co., Ltd., and Mitsubishi Heavy Industries, Ltd. (MHI) have agreed to implement the city gas industry’s first system for transferring and managing Clean Gas Certificates to certify the environmental value of e-methane. The certificates will be managed via the CO₂NNEX® digital platform, developed by Osaka Gas and MHI, and deployed in the Nagaoka Methanation Demonstration, one of the world’s largest methanation projects.

At the demonstration site in Nagaoka City, Niigata Prefecture, hydrogen and CO₂ recovered from INPEX’s Koshijihara Plant will be used to produce e-methane. This e-methane will be injected into INPEX’s natural gas pipeline and supplied to customers, creating a model for local production and consumption. The CO₂NNEX® platform will visualise attribute data for e-methane and its raw materials, manage certificate transfer, and use MRV functions to track usage and ensure correct verification.

Looking ahead, the companies also plan to extend the certificate system to cover liquid fuels such as SAF and e-fuels, as well as gaseous fuels like e-methane and biomethane. The initiative supports the development of certificate-based systems for environmental value management, helping to advance the practical application of methanation technology and contribute to a carbon-neutral society.