ESTUDO DA REDUÇÃO DO TEOR DE ACIDEZ DE ÓLEO ALTERNATIVO VIA MÉTODO ELETROQUÍMICO, VISANDO A PRODUÇÃO DE BIODIESEL

Abstract

Biodiesel is a very important biofuel for the energy transition and the decarbonization process. However, biodiesel production is dependent on raw materials that are commodities, compete with the food industry and reach high market prices, such as soybeans. In order to increase the production and consequent use of biodiesel, it is necessary to have a supply chain, however, some potential oils and fats have high acidity, a characteristic that prevents the reaction widely used in the industry, transesterification, from occurring properly. The present work developed a treatment technique for high acidity oils (60 to 90 mgKOH/g), using electrolysis and sulfuric acid catalyst, with steel and graphite electrodes, obtaining the best result of 96.07% reduction with the use of graphite electrode, with 62.5% ester content. A study on the efficiency of electrode reuse was then carried out, and both electrodes did not show significant drops in efficiency during continuous use. To reach the level required for commercialization of 96.5% ester content, a biodiesel production study was carried out (using the oils treated in the previous stage) with and without electrolysis, with acid and alkaline catalyst from the treated oil , and based on the results it was evident that it is better to conduct the second stage without electrolysis and with an alkaline catalyst, achieving an ester content of 98.52% with the lowest amount of methanol (1:9, oil:methanol M:M) studied. Finally, an economic analysis was carried out, where it was found that the treatment using electrolysis provides savings of almost 3 times, when compared to the traditional method of reducing the acidity of the oil. In this way, it was possible to contribute to the development of a low-cost and high-efficiency process, enabling the insertion of high acidity oils into the biodiesel market and the consequent diversification of raw materials.