Uso da região espectral de sobretons para determinação do teor de biodiesel e classificação de misturas diesel/biodiesel adulteradas com óleo vegetal / Using overtone regions to determine biodiesel content and classification of diesel/biodiesel blends adulterated with vegetable oils

AUTOR(ES)
DATA DE PUBLICAÇÃO

2011

RESUMO

This work evaluates the use of overtone regions (NIR) for the classification and determination of biodiesel content in diesel/biodiesel blends adulterated with vegetable oil. For this purpose, NIR spectra were obtained using three different optical paths: 1.0 mm (9000-4000 cm-1); 10 mm (9000-6300 cm-1) e 50 mm (7500-6300 cm-1). Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) with the Successive Projections Algorithm (SPA) were employed to build screening models to identify adulteration of diesel/biodiesel blends with vegetable oils. The multivariate calibration models (Partial Least Square - PLS, Partial Least Square with significant regression coefficients selected by Jack-Knife algorithm - PLS/JK and Multiple Regression Linear with variable selection by Successive Projections Algorithm - MLR/SPA) were developed to determine the biodiesel content. The results showed that the overtone regions with the classification strategy LDA/SPA can be used in preliminary studies to detect adulteration of diesel/biodiesel blends with vegetable oil. This strategy showed positive results for classifying, with a correct classification rate of 86% for the optical paths of 10 mm and 50 mm. In addition, the work demonstrated the potential of overtone regions with MLR/SPA regression strategy to determine biodiesel content in diesel/biodiesel blends, in the range from 0.0% to 10.0%v/v, considering the possible presence of raw oil as a contaminant. This strategy is simple, fast and uses a fewer number of spectral variables. Considering this, the overtone regions can be usefull to develop low cost instruments for the quality control of diesel/biodiesel blends, considering the lower cost of optical components for this spectral region.

ASSUNTO(S)

misturas diesel/biodiesel espectroscopia nir calibração multivariada classificação quimica diesel/biodiesel blends near infrared spectrometry multivariate calibration classification

Documentos Relacionados