Fernando Carvalho Silva

Production of biodiesel from babassu oil using methanol-ethanol blends

Maranhao state in Brazil presents a big potential for the cultivation of several oleaginous species, such as babassu, soybean, castor oil plant, etc... These vegetable oils can be transformed into biodiesel by the transesterification reaction in an alkaline medium, using methanol or ethanol. The biodiesel production from a blend of these alcohols is a way of adding the technical and economical advantages of methanol to the environmental advantages of ethanol. The optimized alcohol blend was observed to be a methanol/ethanol volume ratio of 80 % MeOH: 20 % EtOH. The ester content was of 98.70 %, a value higher than the target of the ANP, 96.5 % (m/m), and the biodiesel mass yield was of 95.32 %. This biodiesel fulfills the specifications of moisture, specific gravity, kinematic viscosity and percentages of free alcohols (methanol plus ethanol) and free glycerin.

Chemical modification of the surface of alumina with alkaline earth metal oxides using the polymeric precursor method for catalysis application

In this study, modifications of alumina surface with of alkaline earth metal oxides were studied, using the polymeric precursor method. The modified compounds were characterized by X-ray diffraction, nitrogen adsorption-desorption and scanning electron microscopy. The catalytical properties of these new catalysts were evaluated for the transesterification reaction of babassu oil. It is observed that the transesterification reaction of babassu oil with methanol was successfully carried out using the modified alumina samples.

FREE GLYCERIN DETERMINATION IN ETHANOL BIODIESEL UTILIZING SPECTROPHOTOMETRIC AND CHROMATOGRAPHIC (GC/FID) METHODS

According to the Resolution number 7 from the Brazilian National Agency of Oil, Natural Gas and Biofuels (ANP), the official methodologies for free glycerin determination in biodiesel are the ASTM D 6584, EN 14105 and EN 14106 methods. However, these procedures are limited to the analysis of free glycerin in methyl esters and they are not suitable for the analysis of esters from lauric oils. In the present work, a gas chromatographic method was developed for the determination of the amount of free glycerin in ethyl esters from lauric oils, aiming at overcoming the limitations present in the official methods. Moreover, the present method can also be used for ethanol and methanol biodiesel samples from other oily sources. Besides, a methodology that ascertains the content of free glycerin by UV-Vis spectrophotometry was also applied. Both methods were sensitive enough to determine the content of free glycerin in biodiesel, below the limit specified by the ANP, fixed at 0.02 % (200 mg/L), achieving the detection limits of 5.69 mg/L and 2.17 mg/L for the chromatographic and spectrophotometric methods, respectively.

Determination of the composition of biodiesel-diesel blends using the dielectric constant

ABSTRACT There are many methods used to measure the composition of biodiesel in diesel. However, standard methods are limited by high cost and limited precision. Here is proposed a low-cost sensor to determine biodiesel in binary blends of biodiesel/diesel, using the dielectric constant. The concentrations were varied from 0–9% at frequencies from 100–2000 Hz. The correlation curves between the dielectric constant and the biodiesel/diesel concentration included an adjustment factor of 0.992. Moreover, the values of the dielectric constant obtained for each blend were statistically distinct, yielding precise measurements.

Qualitative and Quantitative Chromatographic Methods for Analysis of Glyceroltert-Butylation Reaction Product

This study examined the glycerol tert-butylation reaction products by chromatography. Qualitative analysis by TLC and GC-MS were effective, especially because di-tert-butylglycerols (DTBG) and tri-tert-butylglycerol (TTBG) are not available commercially. In all mass spectra, the GTBE showed ions at m/z 57 and 117, relative to ions of groups tert-butyl [C4H9] + and tert-butoxy-methyl [M-CH3OC(CH3)3] , respectively. The GC-FID method was efficient in the separation of the compounds under study, and had good linearity (R0.997), throughout the interval of 0.60 to 15.0mg.mL, 0.24 to 6.0mg.mL and 0.03 to 1.0mg.mL diisobutylene, glycerin and MTBE, respectively.