Pedro Ramos da Costa Neto

PRODUÇÃO DE BIOCOMBUSTÍVEL ALTERNATIVO AO ÓLEO DIESEL ATRAVÉS DA TRANSESTERIFICAÇÃO DE ÓLEO DE SOJA USADO EM FRITURAS

In this work, the utilization of used frying oil for the production of biodiesel is presented. The performance of biodiesel in diesel engines, as well as the characterization of the emissions derived from this process, are also discussed and compared to the emissions derived from engines running on unused vegetable oils and conventional diesel.

Determination of the oxidation stability of biodiesel and oils by spectrofluorimetry and multivariate calibration.

Oxidation stability is an important quality parameter for biodiesel. In general, the methods used to evaluate the oxidation stability of oils and biodiesels are time-consuming. This work reports the use of spectrofluorimetry, a fast analytical technique, associated with multivariate data analysis as a powerful analytical tool to prediction of the oxidation stability. The prediction of the oxidation stability showed a good agreement with the results obtained by the EN14112 reference method Rancimat. The models presented high correlation (0.99276 and 0.97951) between real and predicted values. The R(2) values of 0.98557 and 0.95943 indicated the accuracy of the models to predict the oxidation stability of soy oil and soy biodiesel, respectively. The residual distribution does not follow a trend with respect to the predicted variables indicating the good quality of the fits.

Alternative technique for biodiesel quality control using an optical fiber long-period grating sensor

We report the use of an optical fiber sensor to measure the soybean oil concentration in samples obtained from the mixture of pure biodiesel and commercial soybean oil. The operation of the device is based on the long-period grating sensitivity to the surrounding medium refractive index, which leads to measurable modifications in the grating transmission spectrum. The proposed analysis method results in errors in the oil concentration of 0.4% and 2.6% for pure biodiesel and commercial soybean oil, respectively. Techniques of total glycerol, dynamic viscosity, density, and hydrogen nuclear magnetic resonance spectroscopy were also employed to validate the proposed method.

Identificação de adulteração de biocombustível por adição de óleo residual ao diesel por espectrofluorimetria total 3D e análise das componentes principais

Total spectrofluorimetry associated to Principal Components Analysis (PCA) were used to classify into different groups the samples of diesel oil, biodiesel, vegetal oil and residual oil, as well as, to identify addition of non-transesterified residual vegetable oil, instead of biodiesel, to the diesel oil. Using this method, the samples of diesel oil, mixtures of biodiesel in diesel and mixtures of residual oil in diesel were separated into well-defined groups.

Utilização de argilas para purificação de biodiesel

This work describes the results of the purification of methyl biodiesel, obtained by oxidized soybean oil, using different methods. After the ester separation from the glycerin by decanting, the ester was purified each time with distillation, washing with water and adsorption with bauxite, bentonite and attapulgite. The removal of total contamination, unsaponifiable material, concentrations of free glycerin and soap were analyzed in the purified ester phase. The best result of purification was observed with the use of bentonite and bauxite, in the removal of soap and free glycerin respectively.

Validation of LED spectrofluorimeter for determination of both biodiesel and nontransesterified residual cooking oil in diesel samples

This paper presents the results of the validation of a LED spectrofluorimeter patented for the analysis of biodiesel in diesel and non-transesterified residual cooking oil (RCO) in diesel. Detection limit, quantification limit and sensitivity were determined from the regression lines. The spectrofluorimeter validated in this study was adequate for quantifying the amount of biodiesel in diesel in the range from 2% to 45% (B02-B45) with an R-squared value of 0.9962 and a detection limit of 3%. For the analysis of non-transesterified RCO in diesel, the linear range was from 2% to 20% with an R-squared value of 0.9872 and a detection limit of 2%. The accuracy of the equipment for the analysis of biodiesel in diesel and non-transesterified RCO in diesel was evaluated using Students t-test for paired data. With 95% confidence level there was no significant difference between the actual values and those determined by the equipment.