Transesterification of sunflower oil with ethanol using sodium ethoxide as catalyst. Effect of the reaction conditions

SANCHEZ, B.S.; BENITEZ, B.; QUERINI, C.A.; MENDOW, G.

FUEL PROCESSING TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 131 p. 29 - 35

0378-3820

Typically, biodiesel is produced using vegetable oil and methanol as raw materials, and sodium methoxide as catalyst,whereupon the obtained product is composed of methyl esters. However, the use of ethyl esters as biodieselpresents many advantages compared to the methyl esters. In this work, the transesterification with ethanol toproduce ethyl esters using sodium ethoxide as catalyst was studied. The effect of temperature and alcohol andcatalyst concentration on the reaction conversion was investigated, in order to optimize these parameterswhile also meeting the quality standards.It was found that the optimal reaction conditions are: 1.6 wt.% sodium ethoxide, 25 v/v% ethanol and 55 °C, whichallow obtaining a biodiesel composed 100% by ethyl esters that complies with the international quality standards.On the other hand, it was observed that methanolysis reactions are faster than the ethanolysis and sodiummethoxide catalyst is more active than the corresponding ethoxide, due to the higher steric hindrance of theethoxi-radical and to the more intense saponification of sodium ethoxide in ethanol medium.