Operation Start of Digital Platform 'CO2NNEX®' for Transfer and Management of Clean Gas Certificates for e-methane in the Nagaoka Methanation Demonstration

INPEX Corporation (INPEX), Osaka Gas Co., Ltd. (Osaka Gas), and Mitsubishi Heavy Industries, Ltd. (Mitsubishi Heavy Industries) have today started the operation of a system for transferring and managing clean gas certificates in the 'World's Largest-scale CO2 Emission Reduction and Effective Utilization Technology Development Project through Methanation (Nagaoka Methanation Demonstration)*1', which is being jointly promoted by INPEX and Osaka Gas. This system, which uses the 'CO2NNEX®*2' platform developed by Osaka Gas and Mitsubishi Heavy Industries, handles the transfer and management of clean gas certificates that securitize the environmental value*3 of e-methane, and is the first mechanism of its kind in the city gas industry.

In the Nagaoka Methanation Demonstration, e-methane will be produced using CO2 and hydrogen (H2) captured at the Koshijihara Plant of the Nagaoka Mine Field (Nagaoka City, Niigata Prefecture) of INPEX JAPAN Ltd., a 100% subsidiary of INPEX, and delivered to consumers via INPEX JAPAN's natural gas pipeline. The e-methane produced at the clean gas production facility*4, certified in January 2026, obtained certification for the equivalent amount of clean gas on May 29. Going forward, to build the local production for local consumption model envisioned in the Nagaoka Methanation Demonstration, the environmental value of e-methane will be converted into clean gas certificates, and efforts to transfer and manage these certificates using CO2NNEX will be advanced together with Nagaoka City, Asahi Shuzo Co., Ltd., and Iwatsuka Confectionery Co., Ltd., which are located near the demonstration facility.

CO2NNEX can enhance the progress management of the entire demonstration by visualizing and centrally managing data such as the volume of e-methane and its raw materials (CO2, H2), lifecycle CO2 emissions, and the acquisition and usage status of clean gas certificates.

Furthermore, a demonstration project for a certificate system*5 for the environmental value of next-generation fuels, including gaseous fuels (e-methane, biogas, etc.) in addition to liquid fuels (e-gasoline, SAF, etc.), is planned. The operation of CO2NNEX in the Nagaoka Methanation Demonstration aims to serve as a pioneering case study for the future establishment of a certificate system.

INPEX, Osaka Gas, and Mitsubishi Heavy Industries will contribute to the social implementation of e-methane and the realization of a carbon-neutral society through this initiative.