OTIMIZAÇÃO DO PROCESSO DE TRANSESTERIFICAÇÃO METÍLICA VIA CATÁLISE ALCALINA DO ÓLEO DE CRAMBE (Crambe abyssinica Hochst)

Abstract

The search for new alternative energy sources to fossil fuels has generated a large number of studies, especially in the area of biofuels and renewable energy. The crambe (Crambe abyssinica Hochst) is an oilseed belonging to the family of Brassicaceae; its cultivation is fully mechanized having 90 to 100 day cycle, with seeds having higher oil content. Because it does not compete in the food industry, the crambe becomes a great option for off-season and biodiesel production. This study aimed to optimize the process of methyl transesterification by alkaline catalysis of crambe oil. For quantification of the response in the transesterification reactions was used the 1H-NMR technique followed by signals interpretation of the signals with software and mathematical equations. From the responses, the response surface methodology technique was applied using the software Design Expert, obtaining a quadratic model able to predict several reaction conditions and their respective answers, with contour plots for visual analysis of the influence of each variable in the model. From the p values, there is the insignificance of the variable ratio oil / methanol in the tested range. The time and temperature are the variables of significant impact on the developed model, with values of p < 0.01. The reaction conditions chosen for the model test was: oil / methanol = 1: 4.5 (m/m); catalyst percentage = 3.5%; temperature = 38 ° C; reaction time = 1.90 hours, with a prediction of 98.0%, and a real answer of 97.80 ± 0.1%.