Protótipo de reator eletroquímico para produção de biodiesel via energia fotovoltaica

Abstract

The continuous increase in global energy demand has driven the search for renewable alternatives capable of replacing fossil fuels. In this study, a prototype electrochemical reactor powered by photovoltaic energy was developed for the production of biodiesel from sunflower oil, using 304 stainless steel electrodes. The system was designed to operate under mild conditions, with adjustable voltage (10-30 V) and different methanol/oil molar ratios (1:3, 1:9). The influence of these parameters on the physicochemical properties of biodiesel, such as acid value, ester content, yield, and density, was evaluated. The electrochemical process yielded more than 90% and ester contents greater than 96.5%, meeting ANP and EN 14214 standards. The acidity index decreased from 1.85 mg KOH.g⁻¹ in the starting oil to 0.18-0.54 mg KOH.g⁻¹ in the biodiesel, demonstrating the efficient conversion of free fatty acids. The density of the samples (881-889 kg.m⁻³) remained within the limits recommended by regulatory agencies. Statistical analysis (Welch's ANOVA) confirmed significant effects of molar ratio and potential difference on the final acidity of the biodiesel. The results demonstrate the technical feasibility of integrating photovoltaic energy and electrolysis for the sustainable synthesis of biodiesel, highlighting the potential of using low-cost materials and renewable energy sources for biofuel production.