Synthetic and reusable potassium aluminate heterogeneous catalyst for biodiesel production

Abstract

The objective of this work was the synthesis of a heterogeneous catalyst (K2O:Al2O3 mixed oxide), for use in biodiesel production through refined soybean oil transesterification. The catalyst was analyzed by FTIR and by basic sites titration. In the transesterification reaction it was used 17.5 % w/w of catalyst compared to soybean oil, molar ratio methanol:oil equal to 9.4:1, with 6 hours of reaction time at 60 °C and 250 rpm. The obtained biodiesel showed specific gravity at 20 °C of 881.53 kg/m3, ester content above 96.5 % w/w (correlated to specific mass) and water content of 236.73 mg/kg. It was possible to perform a reaction and 3 recycles with the catalyst without catalytic activity apparent loss.