Efeito das variáveis operacionais na transesterificação metílica e etílica do óleo de soja

Abstract

In the present work was carried out experimental design for the best reaction conditions of the process of transesterification by soybean oil. There were two plans for an ethanol process route and two for the route methyl, the variables employed were: time (min), speed (RPM), alcohol: oil molar ratio, percentage of catalyst, catalyst type, temperature (0C). The catalysts tested were: NaOH, KOH and potassium ethoxide to the ethylic route and for the methylic route were: NaOH, KOH and potassium methoxide. The condition in which was obtained the highest yield for the production of biodiesel via ethylic route was: time: 60 minutes, speed 100 rpm; ethanol: oil molar ratio: 12:1; percentage of catalyst: 0.2%; type catalyst: potassium ethoxide, temperature: 350C. The condition in which was obtained the highest yield for biodiesel production via methanol route was: time: 30 minutes, speed: 100 rpm, methanol: oil molar ratio: 6:1; percentage of catalyst: 0.2%; type catalyst: KOH; temperature: 55 0C. The biodieseis obtained under optimum conditions of each plan were submitted to physical-chemical properties: acid value, moisture content, density at 20 0C, kinematic viscosity at 40 0C, oxidative stability and carbon residue. The results are consistent with the allowable values of ANP (Resolution 07/2008), with the exception of the parameter oxidative stability of methyl biodiesel from soybeans. The soybean oil used as feedstock for biodiesel production was also subjected to physical and chemical analysis and the values showed that the transesterification of oil would be viable.