Unlocking the potential of Brazilian manganese ores as sustainable and affordable oxygen carriers for chemical looping processes: A step toward clean energy production and carbon storage chain

The increasing frequency of extreme weather events has reduced hydropower reliability, increasing dependence on thermoelectric generation and associated CO 2 emissions. Chemical Looping (CL) is a promising low-carbon alternative, enabling efficient energy production with inherent CO 2 capture, but its performance depends on robust oxygen carriers (OCs). Despite Brazil holding one of the world's largest manganese reserves, their potential as OCs for CL applications remains largely unexplored. The current study is pioneering in proposing the identification of geographical location of Brazilian mines containing manganese ores with favorable physicochemical properties for application as OC for energy conversion processes with inherent CO 2 capture aligning mineral availability with regions of high relevance for geological CO 2 storage and proximity to emission hubs. This study evaluates the performance of five manganese-based OC from Pará (MnHV, MnHB), Ceará (MnHL, MnLL), and Bahia (MnLB). Their reactivity was evaluated in a thermobalance performing redox cycles under methane and hydrogen atmospheres to assess their oxygen transport capacity, redox kinetics, and phase stability. MnHB showed the highest methane reactivity (RI = 1.89%/min) and high oxygen transport capacity (R OC = 3.99%), MnHL achieved the highest R OC (4.38%) and hydrogen reactivity (RI = 10.10%/min), and MnHV exhibited balanced overall performance, with all samples meeting industrial crushing strength requirements. These results identify Pará and Ceará as promising regions for Mn-based oxygen carriers, which are of/close to high relevance areas for geological CO 2 storage, supporting the deployment of CL-based BECCS and low-carbon energy systems in Brazil aligned with SDGs 7, 9, and 12.