In 2019, much of the northeastern coast of Brazil was impacted by a mysterious oil spill that caused an environmental disaster affecting 1009 beaches. Four samples were collected in the beaches between Sergipe and Pernambuco for geochemical characterization of the spilled oil and to compare with those main produced in Sergipe-Alagoas basin. Our approach in this evaluation was the use of a highly selective technique of sequential mass spectrometry by multiple reaction monitoring, to obtain the diagnostic ratios of hopanes and steranes biomarkers. Using these biomarkers ratios associated with multivariate statistical analysis, we found direct correlation between the spilled oil collected along the northeastern coast and no relationship between Sergipe-Alagoas basin crude oils was found. Furthermore, reported data for oils from Orinoco belt in Venezuelan basins were used for qualitative evaluation considering the indicative aspects suggested by the literature. Presence of highly specifi c biomarker 18α(H)-oleanane, and fi ve other important diagnostic ratios evidenced correlation between the spilled oil and Naricual formation crude oils. Besides, due to the oleanane index, Ayacucho's crude oil presented the strongest factor of correlation with the spilled oil found on the northeast coast of Brazil.
In the present work, we compared the chemical profile of the organic compounds produced in non-catalytic pyrolysis of sugarcane bagasse at 500 °C with those obtained by the in-line catalytic upgrading of the vapor phase at 350 °C. The influence over the chemical profile was evaluated by testing two Ni-based catalysts employing an inert atmosphere (N2) and a reactive atmosphere (H2) under atmospheric pressure with yields of the liquid phase varying from 55 to 62%. Major changes in the chemical profile were evidenced in the process under the H2 atmosphere, wherein a higher degree of deoxygenation was identified due to the effect of synergistic action between the catalyst and H2. The organic fraction of the liquid phase, called bio-oil, showed an increase in the relative content of alcohols and phenolic compounds in the GC/MS fingerprint after the upgrading process, corroborating with the action of the catalytic process upon the compounds derived from sugar and carboxylic acids. Thus, the thermal conversion of sugarcane bagasse, in a process under an H2 atmosphere and the presence of Ni-based catalysts, promoted higher deoxygenation performance of the pyrolytic vapors, acting mainly through sugar dehydration reactions. Therefore, the adoption of this process can potentialize the use of this waste biomass to produce a bio-oil with higher content of phenolic species, which have a wide range of applications in the energy and industrial sectors.
In 2019, large amounts of oil reached the northeast coast of Brazil, causing damage to the environment and the local economy, especially in the state of Pernambuco. In order to correlate with possible sources, investigation was made of the geochemical biomarkers of the oils using “gold standard” forensic protocols from the European Committee for Standardization (CEN). The biomarkers study was improved by using gas chromatography-tandem mass spectrometry (GC-MS/MS), rather than the standard protocol that suggests use of the selected ion monitoring (SIM) method. Analysis was made of thirteen oil samples from the Pernambuco coast, in order to identify their degrees of similarity and the possible presence of oils from unreported spills. The use of eighteen diagnostic ratios and multivariate analysis revealed a cluster formed by eleven samples with biomarker distributions typical of oil from the 2019 spill. However, two samples had anomalous fingerprints, especially due to the absence of the 18α(H)-oleanane and 18β(H)-oleanane isomers. Both the CEN protocol applied for the classical biomarkers and a comprehensive Fourier transform mass spectrometry (FT-MS) analysis of polar compounds confirmed the dissimilarities between the samples. The findings suggested that these two oils could have originated from an event unrelated to the mysterious 2019 spill.
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