The homogeneous microwave-assisted sulfuric acid-catalyzed transesterification of soybean
oil, waste Brazil nut oil, sunflower oil and chicken fat for ethylic and methylic biodiesel production is
described herein. The experiments were carried out in pilot-scale multimode reactors. The effects of
the alcohol to oil molar ratio, catalyst concentration and irradiation time on the conversion to biodiesel
were investigated. The transesterification reactions were performed at relatively small alcohol to oil
molar ratios (9:1, 8:1 and 6:1) affording near 100% of conversion in reaction times of 60 to 120 min.
Partial least squares (PLS) regression analysis using FT-NIR spectroscopy was performed to monitor the progress of the
acid-catalyzed methanolysis of soybean oil. The NIR spectra were collected during the transesterification reaction with a
spectrophotometric continuous-flow cell. 1H NMR spectroscopy was employed to determine the conversion percentage
and used as a reference to build the PLS calibration model employing NIR spectroscopy data.
Keywords: Animal fat, FT-NIR spectroscopy, homogeneous acid catalysis, microwave-induced transesterification, sulfuric
acid, vegetable oils.
Rights & PermissionsPrintExport