Brazilian state-controlled energy company Petrobras is testing the Cardano blockchain in two research projects designed to improve the tracking and provenance of lower-emission fuels, including sustainable aviation fuel and renewable-content diesel.

The projects are being developed with the Cardano Foundation and PUC-Rio's Ledger Labs and remain at the research stage. The initiative centers on determining how blockchain-based records could provide verifiable information about the origin, movement, and environmental attributes of fuels.

The research aims to establish on-chain provenance for sustainable aviation fuel and Diesel R, creating traceable records across the different stages of fuel production, transportation, and use.

Neither the Cardano Foundation nor Petrobras has disclosed the volume of fuel covered by the projects or a timetable for broader commercial deployment. No transaction counts, blockchain addresses, record volumes, or live deployment date have been made public.

Sustainable Aviation Fuel Uses a Book-and-Claim Model

One of the projects centers on sustainable aviation fuel, or SAF, and applies a book-and-claim model designed to separate the physical consumption of fuel from the allocation of its environmental benefits. Under the model, an airline could receive the environmental benefit attached to qualifying SAF even when the physical fuel itself is consumed at another location. The system records the origin and the recipient of the environmental claim, allowing participants to trace it back to the underlying fuel certificate.

The design is intended to reduce the risk of double counting emissions reductions, in which the same environmental benefit would be claimed more than once. Digital records are created only after the underlying certificates pass verification procedures. The Cardano Foundation's case study describes checks against relevant aviation standards, including the Carbon Offsetting and Reduction Scheme for International Aviation, or CORSIA. Certificates are then represented as standardized digital tokens carrying information about their environmental attributes, and retirement of a digital certificate is designed to prevent the same environmental benefit from being claimed again.

The project also includes a proposed passenger-facing application. Users would enter their departure and destination airports, after which the application could calculate a corresponding SAF allocation and issue a certificate linked to the original fuel certificate.

Diesel R Tracking Creates a Digital Fuel History

The second research project focuses on Diesel R, which Petrobras describes as diesel containing renewable materials such as vegetable oils or animal fats. The proposed system would create digital checkpoints across the fuel's lifecycle, recording information at stages including production, transportation, and use so that separate records can be connected into a broader history of the fuel.

The Diesel R model is designed to link records across the fuel supply chain, potentially giving companies a more detailed basis for tracking emissions and environmental information associated with fuel use. The Cardano Foundation has highlighted the system's potential relevance to Scope 3 emissions, which cover indirect emissions occurring throughout a company's value chain. Such data can be difficult to collect because it may sit with suppliers, transportation providers, or other businesses. Connecting those records through a shared digital infrastructure could offer organizations a mechanism to consolidate information from different stages of the supply chain. The Diesel R concept, however, remains a proposed research idea rather than a disclosed commercial deployment.

Brazil Emerges as a Cardano Research Market

The Cardano Foundation has identified Brazil as an important market for blockchain experimentation, citing adoption involving government and industrial organizations.

Today, we announce two new initiatives with @Petrobras. As part of an ongoing R&D collaboration with Petrobras and PUC-Rio, the teams have delivered two blockchain applications focused on sustainable aviation fuel and Diesel R, Petrobras' brand of renewable fuel. The work adds…

— Cardano Foundation (@Cardano_CF) September 30, 2026

The Petrobras projects add an energy-sector use case to that activity while also testing whether blockchain infrastructure can support environmental claims that require verification across multiple parties. The collaboration reflects a broader effort to apply distributed ledgers to traceability rather than to financial transactions alone. In the fuel sector, the technology could provide a shared record linking physical products with certificates, environmental attributes, and supply-chain events.

Research Stage Leaves Deployment Uncertain

Despite the potential applications, the projects remain experimental. Petrobras and the Cardano Foundation have not announced fuel volumes, production targets, or dates for wider implementation. The initiative is therefore a research effort to test blockchain-based fuel provenance and environmental-attribute tracking, not a confirmed commercial rollout by Petrobras.

The SAF case study provides the more developed framework, including certificate verification, tokenization, and retirement mechanisms, while the Diesel R concept extends the same traceability approach to successive supply-chain events. Further development would depend on technical results, regulatory requirements, industry participation, and the ability to obtain reliable data from the organizations involved in fuel production and distribution. Progress on those fronts, once made public, would provide the first outward indication of whether either project is advancing beyond the research stage.