A certificate few people know about, and one that could reshape the logic of the gas market
There has been an asset circulating in Brazil’s energy sector since March 2026 that most investors have yet to map. It is not traded on an exchange, at least not for now. It does not appear in financial news. It has no consolidated public price. But it has something every asset needs to exist: compulsory demand created by law, technical regulation approved by a regulatory agency, and a supply window that has not yet kept pace with the obligation.
Its name is the Biometane Guarantee of Origin Certificate. CGOB.
The CGOB is a traceability certificate backed by the volume of biometane produced and commercialized. It was established by the Future Fuel Law within the National Program for the Decarbonization of Natural Gas Producers and Importers and for the Promotion of Biometane, with two main functions: an instrument to prove compliance with the decarbonization target for the natural gas sector and a mechanism to transfer the environmental attribute of biometane.
In plain terms: the CGOB is proof that a quantity of gas has a renewable origin. And that proof, as of 2026, carries market value, both regulatory and voluntary.
The legal framework built in three layers
To understand the CGOB, it is necessary to understand the regulatory architecture that supports it. It was built in three distinct stages between 2024 and 2026.
The first was the approval of Law No. 14,993/2024, the Future Fuel Law, which established the biometane mandate in Brazil, the legal obligation for natural gas producers and importers to incorporate an increasing share of biometane into their supply, starting at 1% in 2026 and scaling up to 10% by 2034. The law also created the CGOB as the central instrument to prove compliance with this mandate.
The second layer was Decree No. 12,614/2025, which regulated the law and established the basic functioning of the program: who the obligated parties are, how targets would be calculated, and the role of the ANP in operationalizing the system.
The third and most recent layer came on March 4, 2026, with the publication by the ANP of Resolutions No. 995 and No. 996/2026, which operationalize the National Decarbonization Program. Resolution No. 995 addresses the individualization of annual mandatory targets for natural gas producers and importers, while Resolution No. 996 regulates the issuance of the CGOB, both linked to the Future Fuel Law.
For the Abegás, these rules strengthen the sector’s regulatory structure by completing the legal framework formed by the law approved in 2024 and the regulatory decree published in 2025. The most relevant point for the market: as of January 1, 2026, invoices for biometane commercialization can already generate CGOBs. Abegas
The instrument has moved off paper. The clock has started ticking.
How CGOB works in practice
The CGOB mechanism has several operational rules that directly determine its market logic and that any investor interested must understand before evaluating opportunities.
One CGOB corresponds to 100 m³ of biometane. This means that each obligated agent’s target is calculated in CGOB units, proportional to the volume of gas it markets.
Obligated parties include producers, self-producers, importers, and self-importers of natural gas, except those producing or importing an average annual volume equal to or below 160,000 m³/day. This exclusion of small agents reduces the regulated universe, concentrating the obligation among large operators in the gas market.
In regulating the CGOB, the ANP established that the certificate will have a validity period of 18 months. The possibility of trading the molecule independently from its environmental attribute was allowed, with specific controls to prevent double counting.
This separation between the molecule and the environmental attribute is one of the most strategic aspects of the system. The CGOB design allows the physical gas to be separated from its environmental attribute, enabling an agent to consume conventional gas locally while simultaneously acquiring the certificate to prove decarbonization. In practice, this means that the CGOB market can function independently of the physical logistics of gas, increasing its potential liquidity and attractiveness as a financial instrument.
The rules also introduced a carry-over mechanism, which allows positive CGOB balances to be counted in subsequent periods, permitting up to 15% of an individual year’s target to be fulfilled in the following period. This mechanism is important to reduce the risk of regulatory non-compliance in years with lower availability of commercial biometane and serves as a buffer for the market in its early years of operation.
Failure to meet the individual annual target will subject the obligated agent to fines ranging from R$100,000 to R$50 million. In the case of repeat offenses, the penalty may be increased by at least 100% of its value.
This penalty structure is what transforms the CGOB from a symbolic environmental certificate into an asset with real economic value. Without fines, there is no demand pressure. With meaningful penalties, obligated agents have a concrete incentive to purchase CGOBs, and biometane producers have an economic reason to issue them.
CGOB and CBIO: similarities, differences, and what the RenovaBio experience teaches
It is impossible to discuss the CGOB without drawing a parallel with the CBIO, the Decarbonization Credit created by RenovaBio in 2017, which has become the most liquid environmental asset in Brazil’s biofuels market.
The similarities are structural. Both are market instruments designed to drive greenhouse gas reductions and promote renewable energy, sharing the logic of mandatory targets for specific sectors and a retirement mechanism to prevent double counting.
But the operational differences are equally relevant and define distinct market dynamics. CBIO is fully detached from the molecule, fungible, and traded in an organized market without an expiration date. CGOB, on the other hand, is preferably acquired attached to the molecule, traded bilaterally, has a validity period, and its pricing is linked to the physical product and declared price.
This has concrete implications. Because CBIO is fungible and traded on B3, it has transparent price formation, liquidity, a secondary market, and accessibility for financial investors. CGOB, at least in its current configuration, operates through bilateral contracts, which means lower immediate liquidity, less transparent price formation, and greater dependence on direct commercial relationships between biometane producers and obligated agents.
This difference is not necessarily a permanent disadvantage. It is a characteristic of a nascent market. RenovaBio also started in a more restricted way before gaining scale and liquidity. The key question for investors is: what will be CGOB’s trajectory?
This opens up two forms of trading and pricing: CGOB with and without registry retirement. In other words, there are two markets for the same product: one for CGOBs that have already passed through a natural gas producer and another from the primary issuer. This dual dynamic may, over time, create a secondary market with its own pricing logic.
CGOB in the broader context of Brazilian decarbonization
CGOB does not exist in isolation. It fits into a broader regulatory architecture that Brazil is building throughout 2026, and this convergence increases its strategic relevance.
From the regulator’s perspective, the certificate presented by natural gas producers and importers within the Decarbonization Program has market value and can also be traded by agents seeking to offset emissions in their sustainability reports, such as GHG Protocol, GRI, and IFRS S1 and S2 standards.
This means that CGOB has potential uses beyond mandatory compliance. Companies that are not gas producers or importers but have voluntary decarbonization commitments with stakeholders, financiers, or international investors can also acquire CGOBs to demonstrate emissions reductions in their natural gas-based production processes.
This voluntary dimension expands the pool of potential buyers and, consequently, the asset’s potential liquidity and appreciation over time. It is a trend, not a guarantee, but a trend grounded in real regulatory foundations.
There is also a connection with the Brazilian Emissions Trading System (SBCE), created by Law No. 15,042/2024, whose secondary regulation is expected to be finalized by December 2026. Depending on how SBCE is structured, biometane projects may accumulate both CGOBs and regulated carbon credits, creating dual monetization of environmental attributes for the same volumes of renewable gas produced. This hypothesis still awaits regulatory confirmation, but it is one of the key developments being closely monitored by market participants.
What investors need to watch and the risks they should not ignore
Given this scenario, what is the appropriate interpretation for those following the energy market with an allocation perspective?
The first opportunity is the most direct: biometane production with CGOB issuance. Any facility that processes organic waste, landfills, wastewater treatment plants, slaughterhouses, agribusiness, and converts biogas into market-quality biometane now has, in addition to gas revenue, the potential revenue from CGOBs issued. For projects under development, CGOB becomes an additional variable in projected cash flow, potentially improving IRR attractiveness in projects that would otherwise have marginal returns.
The second opportunity is more structural: certification, traceability, and CGOB management infrastructure. Biometane producers must hire ANP-accredited certifiers to verify production volume, feedstock used, and emissions intensity. Based on this information, CGOBs can be issued. This ecosystem of certification, auditing, and registry is still being built and represents a service chain with demand guaranteed by the regulatory framework itself.
The risks, however, deserve proportional attention.
The main short-term risk is the mismatch between supply and demand. The 1% mandate is already in force, but the available volume of commercial biometane for CGOB issuance is still limited. Targets for 2026 will be published on the ANP website within one month after the first CGOB is issued, and compliance will be required together with the 2027 target. This creates a transition period that is useful but does not eliminate the risk that obligated agents may struggle to find enough CGOBs in the market, especially in regions with less gas infrastructure and fewer biometane plants.
The second risk is regulatory. The CNPE still needs to define annual targets for the first cycles, and the law provides for the possibility of target flexibility when biometane supply is insufficient. CNPE may, exceptionally, adjust the annual emissions reduction percentage, even below 1%, for justified public interest reasons or when biometane production volumes make compliance unfeasible or excessively costly. This clause reduces systemic risk but also introduces uncertainty about the market’s growth curve, complicating long-term CGOB pricing.
The third risk is liquidity. For now, CGOB is traded bilaterally, without an organized market. For investors accustomed to exchange-traded assets, this represents a significant comfort gap. Bilateral pricing tends to be less transparent, more volatile, and more dependent on each agent’s bargaining power.
Conclusion
Brazil has a strong track record of decarbonization instruments that began obscure and gained scale over time. The RenovaBio, when it was created, was also unknown to much of the financial market. Today, CBIOs are regularly traded on B3 and are part of alternative asset portfolios.
CGOB is at the beginning of this path, with the advantage of benefiting from lessons learned and from a global regulatory environment more favorable to carbon pricing than in 2017.
For investors, the most balanced reading is this: CGOB is not yet a liquid or mature asset. But it is an asset with compulsory demand, a solid legal foundation, approved technical regulation, and appreciation potential in a market that is still forming. Those who enter early, with appropriate risk precautions, will be positioned to capture the value of this formation before the market prices this opportunity efficiently.
In clean energy, as in any emerging market, timing rarely comes back.
