Brazilian state-controlled energy company Petrobras is testing two research-stage blockchain applications developed with the Cardano Foundation and PUC-Rio's Ledger Labs for sustainable aviation fuel and Diesel R, its renewable diesel made partly from vegetable oils and animal fats. The Cardano Foundation announced the projects on Sept. 30, 2026, following a collaboration that began with blockchain education for Petrobras employees in 2023 and expanded into energy-sector research in 2025. The aviation application uses a Book-and-Claim model that separates an environmental benefit from the physical fuel and represents verified claims as CS-SAF tokens. A passenger-facing tool is designed to provide certificates connecting a journey with an allocated environmental benefit. The Diesel R project uses digital checkpoints across production, distribution and consumption to create a traceable record that could support Scope 3 emissions reporting. Both initiatives remain research projects, with neither deployment dates nor covered fuel volumes disclosed. Petrobras and the Cardano Foundation have not specified whether the systems will directly affect ADA usage. Separately, technical analyst Crypto Patel identified $1, $3 and $5 as ADA price targets, while stating a weekly close below $0.137 would invalidate the bullish scenario.