Desenvolvimento de células a combustível abastecidas com extrato de cana-de-açúcar: uma opção para geração de energia com menor impacto ambiental

Abstract

Carbohydrates are widely found in nature and play a crucial role as energy sources. In Brazil, for example, approximately 16% of the energy matrix comes from sugarcane. In this context, the present thesis proposed an innovative approach using direct liquid fuel cells, fueled with sugarcane juice extract as a viable alternative to ethanol and hydrogen. This approach offers advantages, such as better logistical and smaller environmental impact compared to the vinasse generated in the alcohol production process. The main objective of this study was to investigate the oxidation of sugarcane extract in platinum and palladium catalysts to identify the most active metal for this reaction. The results revealed that the platinum catalyst exhibited higher activity in sugar oxidation, resulting in a power density ten times greater than that achieved with palladium. Furthermore, the research evaluated the possibility of reducing the production costs of fuel cells and enhancing their activity by partially replacing platinum in the catalyst with tin.The addition of tin to the catalyst led to an activity increase of over eight times compared to pure platinum. The Pt 90 Sn 10 /C composition with MPD of 8.7 mW cm -2 proved to be particularly more active than other prepared electrocatalysts, and importantly, no vinasse generation was observed during the oxidation of the synthetic sugarcane juice solution in the fuel cell.The results demonstrated that fuel cells directly fueled with sugarcane juice are fully functional and represent a promising option for converting sugarcane juice (biomass) into energy without generating vinasse waste.