MCR-ALS with correlation constraint and Raman spectroscopy for identification and quantification of biofuels and adulterants in petroleum diesel

Abstract Raman spectroscopy and multivariate curve resolution with correlation constraint were used for the identification and quantification of biofuels and adulterants in petroleum diesel. Firstly, quantification of two biofuels present in petroleum diesel (biodiesel and hydrotreated esters and fatty acids (HEFA)) was performed. The developed models for biodiesel and HEFA presented RMSEPs equal to 0.70%, indicating the practical application of the proposed methodology. Additionally, the identification and quantification of six adulterants (ethanol, cyclohexane, gasoline, hexane, kerosene and an ethanol/gasoline blend) in petroleum diesel with 10% of biofuels (B-10) were performed. In this case, it was possible to identify the adulterant with high confidence based on the recovered spectra and to estimate its concentration with absolute errors below to 8%.