Brazilian oil giant Petrobras is testing Cardano blockchain technology in research projects designed to improve the traceability of lower-carbon fuels and prevent environmental benefits from being claimed more than once. The work centers on sustainable aviation fuel (SAF) and renewable fuel attributes.

Petrobras is developing the system with PUC-Rio's LedgerLabs and the Cardano Foundation. The research, detailed in a Cardano Foundation case study, explores how blockchain can record sustainability data across fuel production, certification, trading, and end use.

Reliable tracking of these attributes has become increasingly important as companies seek to document emissions reductions. Brazil's energy regulator, the ANP, requires SAF certificates to capture information including fuel volume, feedstock, production process, origin, and emissions reductions. Under the regulator's rules, environmental attributes may also be separated from the physical fuel through a Book-and-Claim model, provided safeguards prevent double counting. In practice, that separation allows a participant to hold the environmental benefit tied to a volume of fuel without taking physical delivery of the fuel itself. Double counting matters here because a single reduction claimed by two parties would make documented emissions savings unreliable.

Blockchain Targets Double Counting

Under the Petrobras project, renewable fuel attributes can be represented as digital tokens on Cardano. The Cardano Foundation says the system assigns each attribute a unique record that can be transferred and eventually retired. Retiring a record, in this design, closes out that benefit so it cannot be claimed again. That structure is intended to make sustainability claims verifiable and to ensure the same environmental benefit cannot be used twice. It could also improve visibility when physical fuel and its environmental attributes move through different parts of the supply chain.

Petrobras already produces SAF with renewable feedstocks through co-processing at its Duque de Caxias refinery. The company says the renewable portion can deliver more than 80% lower carbon dioxide emissions than its fossil counterpart.

Blockchain Fits Wider Fuel Strategy

The research comes as Petrobras expands its renewable-fuel ambitions. The company plans dedicated production facilities for bio-jet fuel and renewable diesel, including a project at its Presidente Bernardes refinery with planned capacity of up to 15,000 barrels per day. Scaling up dedicated production would also increase the volume of sustainability data that needs to be recorded and verified across the supply chain.

For fuel buyers and market participants, the blockchain work could provide another layer of transparency around environmental claims. However, the technology remains part of Petrobras' research and development program rather than a replacement for regulatory certification. How far the tokenized approach moves beyond research, and how it would fit alongside ANP certification and the Book-and-Claim framework, are the details to watch as Petrobras advances its renewable fuel expansion.

The broader goal is to create a traceable digital record that links fuel attributes to measurable emissions data, giving participants a clearer way to verify sustainability claims across the energy value chain.