Produção de biodiesel via esterificação do ácido oléico utilizando etanol hidratado

Abstract

The esterification reaction of pure oleic acid with hydrous ethanol was studied when the process was carried out using sulfuric acid as catalyst. The negative effect of the water on the yield of biodiesel obtained by this reaction was reduced by adsorption techniques in an experimental apparatus. It contains a column filled up with Zeolite 3A which removed the water formed in this reaction. The aim of this work was to optimize the experimental conditions to produce biodiesel using low cost raw materials so that this biofuel could be more competitive with petroleum diesel. Several factors can affect the yield of the esterification reaction as the alcohol to the free fatty acid molar ratio, the catalyst amount, and the temperature. The effect of these factors on the yield of biodiesel was studied. To evaluate each parameter to be studied, it was elaborated a 23 experimental design. Based on this design, the alcohol to the free fatty acid molar ratio, the catalyst amount, and the temperature were studied and the data was handled using software STATISTICA v7.0 (Statsoft,Tulsa, OK). The results showed that the reaction carried out using the adsorption apparatus to reduce the amount of water in the system presented the highest yield of biodiesel. Due to this less amount of water, it was not necessary to use a large alcohol to free fatty acid molar ratio to obtain yields of biodiesel over 99 %. The best operation condition was observed when the temperature, alcohol to oleic acid molar ratio, and catalyst amount were respectively, 110 °C, 3:1, and 1% (w/w).