The certificate is proof that the carbon used to make it came from capture, not from new drilling.
In Nagaoka City, Japan, a collaboration between industrial giants and local community partners has begun certifying synthetic methane with digital proof of its environmental value — a quiet but consequential step in humanity's long effort to reconcile energy use with atmospheric responsibility. The fuel, made by recombining captured carbon dioxide with hydrogen, carries a legal claim of zero net emissions, and a blockchain platform now makes that claim traceable, tradeable, and transparent. What unfolds here is less a technical novelty than a test of whether trust can be engineered into the infrastructure of a low-carbon economy.
- Japan's carbon neutrality ambitions depend on scaling synthetic fuels, yet no verified market for their environmental value has existed — until now.
- A Nagaoka facility began injecting e-methane into a live natural gas pipeline in February 2026, and by late May had received official certification to issue tradeable Clean Gas Certificates.
- The CO2NNEX platform disrupts conventional carbon accounting by making the entire supply chain — raw materials, production volumes, lifecycle emissions — visible in real time to every participant, including a local sake brewery and a confectionery company.
- The risk of double-counting credits, unverifiable claims, and fragmented data threatens to undermine synthetic fuel markets before they mature, and Nagaoka is the live stress-test for solving those problems.
- Japan's METI is watching closely, intending to use this demonstration as the operational blueprint for a national clean fuel certificate system spanning synthetic methane, aviation fuel, and biogas.
In Nagaoka City, northwest of Tokyo, a demonstration project is doing something Japan has never done before: issuing digital certificates that prove the environmental worth of synthetic methane as it flows through a real gas pipeline. The facility, certified as a clean gas production site in January 2026, began injecting e-methane — made by combining hydrogen with captured CO2 — into INPEX JAPAN's pipeline in February. On May 29, it received official clean gas equivalent certification, making its output eligible for tradeable Clean Gas Certificates.
The collaboration involves INPEX, Osaka Gas, and Mitsubishi Heavy Industries, alongside Nagaoka City and two local manufacturers. The environmental logic is precise: because the CO2 used as feedstock would otherwise have entered the atmosphere, and because combustion returns it without adding new carbon, the fuel carries zero net emissions. That claim now has legal standing and a digital backbone.
The platform managing it all is CO2NNEX, developed by Mitsubishi Heavy Industries. It tracks production volumes, raw material inputs, and lifecycle carbon data across the entire operation, feeding that information in real time to Asahi-Shuzo, a sake brewery founded in 1920, and Iwatsuka Confectionery, established in 1947, as well as to Nagaoka City government. Each participant can trace their share of the environmental benefit — a model the partners call 'local production and local consumption.'
The stakes extend well beyond Nagaoka. Japan's Ministry of Economy, Trade and Industry plans to build a national clean fuel certificate system covering synthetic methane, synthetic gasoline, sustainable aviation fuel, and biogas. This demonstration is the live test case — working out how to verify production data, prevent double-counting, and integrate blockchain verification with industrial processes. For INPEX, Osaka Gas, and Mitsubishi Heavy Industries, each of which has staked its energy transition strategy on this moment, the certificates are now live and the data is flowing. Whether the broader market follows is the question that remains.
In Nagaoka City, a few hours northwest of Tokyo, a demonstration project has begun converting captured carbon dioxide and hydrogen into synthetic methane—and now, for the first time in Japan, that methane comes with a digital certificate proving its environmental worth. The facility, certified as a clean gas production facility in January 2026, started injecting the synthetic fuel into INPEX JAPAN's natural gas pipeline in February. By late May, the partners had taken the next step: launching a blockchain-based tracking system to document and trade the environmental value embedded in every unit of gas produced.
The project is a collaboration between three major players—INPEX, Osaka Gas, and Mitsubishi Heavy Industries—working with two local manufacturers and Nagaoka City itself. The synthetic methane, called e-methane, is made by combining hydrogen with CO2 recovered from the Koshijihara Plant. The environmental claim is straightforward: because the carbon dioxide used as raw material would otherwise have entered the atmosphere, and because the resulting methane is burned in a closed loop that doesn't add new carbon to the air, the fuel carries zero net emissions. That claim now has legal standing. The facility received official clean gas equivalent certification on May 29, making it eligible to issue tradeable Clean Gas Certificates.
The digital infrastructure managing these certificates is called CO2NNEX, a platform developed by Mitsubishi Heavy Industries to visualize and track carbon supply chains. In the Nagaoka demonstration, CO2NNEX does something more ambitious than simple record-keeping. It ingests data on the volume of e-methane produced, the raw materials consumed, and the lifecycle carbon footprint across the entire operation. That data flows to two local companies—Asahi-Shuzo, a sake brewery established in 1920, and Iwatsuka Confectionery, founded in 1947—as well as to Nagaoka City government. Each can see in real time how much clean gas was produced, track its journey through the pipeline, and hold certificates representing their share of the environmental benefit. The system enables what the partners call "local production and local consumption," a model where the communities nearest the facility directly benefit from its environmental value.
This is not merely symbolic. Japan's Ministry of Economy, Trade and Industry has announced plans to launch a broader clean fuel certificate system covering synthetic methane, synthetic gasoline, sustainable aviation fuel, and biogas. The Nagaoka demonstration is being run as a live test case. The operational knowledge and technical lessons learned here—how to verify production data, how to prevent double-counting of environmental credits, how to transfer certificates between parties, how to integrate blockchain verification with traditional industrial processes—will inform the design of that national system. The stakes are substantial. If Japan is to meet its carbon neutrality targets while maintaining energy security, it needs to scale synthetic fuels and create markets for them. That requires trust, transparency, and a way for buyers to verify what they're actually purchasing.
The three corporate partners have each staked their energy transition strategies on this moment. INPEX, in its Vision 2035, committed to providing lower-carbon solutions and integrating carbon capture into its natural gas projects. Osaka Gas, through its Energy Transition 2050 roadmap, aims to develop technologies that support a carbon-neutral society. Mitsubishi Heavy Industries is positioning itself as a global leader in carbon capture, utilization, and storage—and CO2NNEX is its bid to become the operating system for that ecosystem. What happens in Nagaoka over the next months will shape whether these ambitions can move from demonstration to scale. The certificates are now live. The data is flowing. The question is whether the market will follow.
Citas Notables
The environmental value of e-methane is converted into Clean Gas Certificates, enabling visualization and central management for the entire demonstration project.— Mitsubishi Heavy Industries project statement
La Conversación del Hearth Otra perspectiva de la historia
Why does a synthetic fuel need a digital certificate? Isn't the fuel itself the proof of what it is?
The fuel is real, but the environmental claim is invisible. When you burn e-methane, it looks identical to natural gas. The certificate is proof that the carbon used to make it came from capture, not from new drilling, and that the lifecycle accounting is honest. Without it, there's no way for a buyer to know they're actually getting what they paid for.
So this is about preventing fraud in the carbon market.
Partly that. But it's also about creating a market at all. If Asahi-Shuzo wants to use clean gas and tell customers about it, they need documentation. The certificate is what makes that claim credible and tradeable.
Why involve local companies like a sake brewery and a candy maker? Why not just sell the gas to utilities?
Because the whole point is to prove the model works at scale. If only large corporations benefit, it's a niche experiment. But if a 100-year-old sake brewery in Nagaoka can use the gas and hold the certificate, and if that becomes normal, then you've shown the system can work for anyone.
What happens if the certificate system fails? If the data is wrong or someone cheats?
That's why the government is watching so closely. The Nagaoka demonstration is essentially a stress test. If problems emerge here, they fix them before rolling out nationally. If it works, they scale it. The whole future of synthetic fuel markets in Japan depends on getting this right.
And if they don't get it right?
Then synthetic methane stays a curiosity instead of becoming part of the energy mix. Japan's carbon targets slip further out of reach.