Débora de Oliveira^*, Marco Di Luccio, Carina Faccio, Clarissa Dalla Rosa, João Paulo Bender, Nádia Lipke, Cristiana Amroginski and José Vladimir de Oliveira

Department of Food Engineering

URI-Campus de Erechim

Av. Sete de Setembro, 1621

Erechim, RS, Brazil, 99700-000

Phone: (+55) 54-5209000

Fax: (+55) 54-5209090

E-mail: odebora@uricer.edu.br

Transesterification of vegetable oils, a renewable resource, to result in a sulfur-free product known as biodiesel, has great potential as an additive to mineral diesel to reduce environmental investments and import needs. It is well known that the transesterification process using alkaline catalysts and short-chain alcohols, like ethanol, allows fast reaction times with high yields. The objective of this work is to report the production of fatty acid ethyl esters from soybean oil and castor oil, as raw materials, using NaOH as catalyst. A Taguchi experimental design was adopted considering the variables temperature (30-70^oC), reaction time (15 min to 3 h), concentration of catalyst (0.5-1.5 wt/wt%) and the oil to ethanol molar ratio (1:3 to 1:9). An empirical model was then built so as to assess the main and cross variable effects on the reaction conversion and also to maximize the biodiesel production for each system investigated. Results show that, in general, an increase in catalyst concentration and in the alcohol-oil ratio leads to an enhancement in the reaction conversion, while an opposite trend was verified with respect to the reaction temperature.