Navegando por Autor "Araújo, Antônio S."
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Artigo Analysis of petroleum oily sludge produced from oil-water separator(Universidade Federal do Rio Grande do Norte, 2014-07-08) Chiavone Filho, Osvaldo; Lima, Cícero S.; Lima, Regineide de Oliveira; Silva, Edjane Fabiula Buriti da; Castro, Kesia Kelly Vieira de; Soares, Sandra A.; Araújo, Antônio S.The petroleum oily sludge is formed during the production, transportation, and storage processes as well as in the oil refinery plant. The elemental analysis was performed with samples of petroleum oily sludge collected in the State of Rio Grande do Norte. For the carbon and hydrogen elements, small differences were observed between them, but for the oxygen element, bigger differences between the sludge samples were noticed. They have presented differences in the chemical composition of inorganic and organic parts. The sludge from oil-water separator (OWS) 2 showed a high amount of oil (94.88%), being considered a high value-added residue by the oil industry. In the analyses of saturated, aromatics, resins, and asphaltenes (SARA) components, the sludge from the unloading had a high amount of saturates. The inorganic material separated from the sludge of the OWS 2 was characterized, and presented a lot of sulfur (41.57 %). The sludge analyzed showed a high value of organic components, thus such material can be handled and reprocessed in processing units within the oil industryArtigo Structural and morphological characterization of Pt/WOx–ZrO2 Catalysts(Springer, 2008-08-09) Melo, Marcus Antônio de Freitas; Pedrosa, Anne Michelle Garrido; Melo, Dulce Maria de Araújo; Souza, M. J. B.; Araújo, Antônio S.; Lima, S. H.; Sasaki, José MarcosCatalysts of Pt/WOx–ZrO2 type with 1 wt% of Pt and 10, 15 and 20 wt% of tungsten were synthesized and characterized. The structural and morphological features of these catalysts were studied. The samples were synthesized by impregnation method and calcined at 600 C, 700 C and 800 C. The characterizations were carried out using different techniques: X-ray diffraction, Raman spectroscopy, scanning electronic microscopy, nitrogen adsorption measurement and refinement of their crystalline structures by Rietveld method. X-ray diffraction patterns revealed the formation ZrO2 and WO3 crystalline structures and its crystallite size were determined. The zirconium oxide crystallized into tetragonal and monoclinic phases and tungsten trioxide crystallized into monoclinic phase. Crystalline WO3 and amorphous WOx species were detected by Raman spectraArtigo Systems involving cobalt and cerium oxides: characterization and catalytic behavior in the C6–C7 n-alkanes combustion(Elsevier, 2003-05) Pedrosa, Anne Michelle Garrido; Sousa, Marcelo José Barros; Melo, Dulce Maria de Araújo; Araújo, Antônio S.; Zinner, Léa Barbieri; Fernandes, Joana D. G.; Martinelli, Antonio EduardoThe objective of this work is to report the characterization and catalytic behavior of Co3O4, CeO2, and Co3O4–CeO2 catalysts in the C6–C7 n-alkanes combustion. X-ray diffraction indicated that crystalline oxides of Co3O4 and CeO2 are obtained by heat treatment at temperatures higher than 600 °C. The FTIR spectra are characteristic of cobalt and/or cerium oxides. The reactions were processed in a fixed bed continuous flow reactor, at 450 °C varying F/W ratio and n-alkanes. The results obtained showed that the catalysts give good activity in the C6–C7 n-alkanes combustion with high selectivity to carbon dioxide