The Cardano Foundation’s collaboration with Brazil’s state-controlled energy company Petrobras and PUC-Rio has evolved from employee education into research-stage blockchain applications aimed at tracking sustainable aviation fuel (SAF) and a renewable-content diesel called Diesel R. The relationship began in December 2023 with Cardano Academy training for roughly 40,000 Petrobras employees; the first 500 participants received evolving NFTs as credentials. A 2024 pilot of a Proof of Atenas attendance and training verification system used NFC cards and 3D-printed totems to record participation on-chain, and the partnership’s work continued through 2025 and 2026 into application development.
Two research applications were announced. The aviation project implements a Book-and-Claim model in which digital tokens represent environmental benefits tied to verified fuel certificates. Cardano’s SAF case study describes a certificate-checking step against CORSIA and other standards; once verified, certificates become standardized tokens (the Foundation identifies CS-SAF as the aviation benefit token) that can be issued, transferred, inspected and retired so the same benefit cannot be claimed twice. The model separates physical fuel use from the allocation of environmental benefits and includes a dApp to calculate SAF allocations for specific passenger routes and to issue certificates linking routes, distances and allocations back to original fuel certificates.
The Diesel R project creates digital checkpoints to record production, transport and use, linking successive records so companies can consult a connected fuel history when preparing Scope 3 emissions reports. Petrobras describes Diesel R as diesel with a renewable portion produced by co-processing petroleum diesel with vegetable oils or animal fats and refined with hydrogen and catalysts; the product can use existing engines, storage and distribution infrastructure. Petrobras began commercial domestic deliveries of SAF in December 2025 with an initial batch of 3,000 cubic meters and has a stated target to meet Brazil’s domestic SAF demand through co-processing between 2027 and 2029.
Both initiatives remain research projects with no commercial launch date disclosed. The announcements situate the work within a broader set of industry experiments: Shell’s Avelia book-and-claim platform, launched in 2022, has contributed to more than 84 million gallons of SAF entering the global network through June 2026, resulting in more than 780,000 tonnes of CO2e abatement, and other companies such as Viva Energy are researching digital book-and-claim approaches. Cardano frames the effort as a way to build trust in environmental data across complex supply chains by anchoring verifiable records and preventing double claims.