Producción de biodiesel: cinética de esterificación con etanol. Catálisis homogénea y heterogénea

MA. LAURA PISARELLO1*, CLAUDINEY SOARES CORDEIRO2, CARLOS A. QUERINI1

LA PLATA

Congreso; XV Congreso Argentino de Catálisis y 4° Congreso de Catálisis del MERCOSUR; 2007

CONACA

Biodiesel is a fatty acid ester mixture, where the alkyl group is typically a methyl or ethyl radical, obtained from renewable raw materials, like vegetal oils and animal fats. The esterification reaction of fatty acids in high acidity raw materials, and therefore of low commercial value, with alcohols of short chain (methanol, absolute ethanol and ethanol 96%), was specifically studied in this work. Although the water is detrimental for the reaction, it is important to find the adequate reaction conditions to work with ethanol 96% for economic and practical reasons. The optimal conditions of reaction were studied (H2SO4 catalyst concentration, molar ratio alcohol: fatty acid and reaction temperature), and its influence on the reaction rate, making emphasis in the esterification with ethanol, and the determination of kinetic parameters.  A preliminar study using a solid acid catalyst was also carried out.  A Nb2O3.nH2O, commercially available as HY-340, was tested at different temperatures, pressures and methanol/fatty acid ratios.  Even though the catalyst is less active than the sulfuric acid, it is important to follow the research in the field of solid catalysts since it makes possible to simplifies the purification process.