Brazilian state-controlled oil company Petrobras has developed two blockchain applications built on Cardano to track sustainability data for sustainable aviation fuel (SAF) and its Diesel R renewable diesel.

According to a Wednesday announcement from the Cardano Foundation, which also published a case study and publicized the initiative in a post on X, the first application was developed with PUC-Rio's Ledger Labs. It tokenizes the environmental attributes associated with SAF into digital tokens designed to prevent the same claim from being used more than once.

The application follows a Book-and-Claim model, which allows the environmental benefit to be separated from the physical fuel and assigned to an airline, company or passenger even if the SAF is used elsewhere. Preventing the same unit of environmental benefit from being claimed twice is central to making such a model credible. The resulting tokens, known as CS-SAF, carry metadata aligned with the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), the International Civil Aviation Organization's scheme for addressing CO₂ emissions from international flights. Passengers can also claim CS-SAF tokens through an application and receive a certificate tied to their journey and its associated environmental claim.

The second application creates digital checkpoints to track the production, transportation and use of Diesel R, Petrobras' renewable diesel fuel. The Cardano Foundation said the data generated could support Scope 3 reporting, which covers indirect emissions across a company's value chain, spanning supplier, transport and end-use activities tied to a company's products.

The projects sit within an ongoing research and development collaboration that began in 2023 with blockchain education for Petrobras employees and expanded in 2025 into energy-sector research with PUC-Rio's Ledger Labs. The Cardano Foundation did not disclose the fuel volumes covered by the applications or a timeline for broader deployment, leaving open how quickly the tools could move beyond research and development into wider operational use.

Blockchain finds use in sustainable aviation fuel tracking

Petrobras is not the only energy company exploring blockchain for SAF accounting. Shell has also used blockchain to track environmental attributes associated with sustainable aviation fuel through Avel, a Book-and-Claim platform launched in 2022 that records claims and prevents double counting. In a September update, Shell said Avelia had contributed to more than 84 million gallons of SAF entering the global fuel network since its launch in 2022, resulting in more than 780,000 tonnes of CO₂e abatement through June 2026.

More recently, Australia's Viva Energy signed an agreement with NoviqTech in January to research digital Book-and-Claim systems for sustainable aviation fuel, including how blockchain could support emissions reporting and track environmental claims.