Roberta Gomes Prado
UFMG, Brazil
Title: Ethanolysis and methanolysis of soybean and macauba oils catalyzed by mixed oxide CaAl from hydrocalumite for biodiesel production
Biography
Biography: Roberta Gomes Prado
Abstract
Homogeneous catalysis is a common industrial process for biodiesel production, and alkali-metal methoxides are often used as catalysts. These catalysts allow for obtaining high conversion rates using reactions with low temperatures and times shorter than 1 h. However, the drawbacks of their use are that these catalysts are unrecoverable, favour saponification reactions and generate large volumes of aqueous effluents with environmental impacts. The objective of this study was to synthesis and characterization of the Ca-Al mixed oxide produced from the thermal decomposition of a synthetic hydrocalumite. The produced mixed oxide was tested as a catalyst in the transesterification reaction for biodiesel production using the following reagents: refined soybean oil, crude macauba kernel oil, methanol, and ethanol. The synthetic hydrocalumite and mixed oxide were characterized by powder X-ray diffraction, thermogravimetry-differential scanning calorimetry coupled with mass spectrometry, specific surface area, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and temperature-programmed desorption of CO2. The catalytic tests indicated that the methanol reactions exhibited more favourable kinetics than the ethanol reactions regardless of the oil type used (soybean or macauba). Ethanolysis produced better results for the higher molar-mass oil (soybean) due to the effect of the ethanol co-solvent. The catalyst was efficient for transesterification, with conversions of 97% e 95% for soybean and macauba oil respectively, in 1.5 h of reaction, at atmospheric pressure and reflux temperature. The mixed oxide presented more favorable kinetics than the CaO, using soybean oil and methanol.