Development of an Electrochemical Reactor Prototype for Biodiesel Production Powered by Photovoltaic Energy

The continuous increase in global energy demand has intensified the search for renewable alternatives capable of replacing fossil fuels. In this study, an electrochemical reactor prototype powered by photovoltaic energy was developed for biodiesel production 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 oil:methanol molar ratios (1:3–1:9). The influence of these parameters on the physicochemical properties of the produced biodiesel was evaluated, including acid value, ester content, yield, and density. The electrochemical process achieved yields above 90% and ester contents exceeding 96.5%, meeting the standards established by ANP and EN 14214. The acid value decreased from 1.85 mg KOH·g–1 in the feedstock oil to 0.18–0.54 mg KOH·g–1 in the biodiesel, indicating 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 the molar ratio and applied potential on the final acid value of the biodiesel. The results demonstrate the technical feasibility of integrating photovoltaic energy with electrolysis for sustainable biodiesel synthesis, highlighting the potential of low-cost materials and renewable energy sources for biofuel production.