Remoção de contaminantes nitrogenados e sulfurados de cargas modelo de óeo diesel: estudo do adsorvente

• Ano de defesa: 2007
• Autor(a) principal: Silva Junior, Paulo Ferreira da
• Orientador(a): Zotin, Fatima Maria Zanon
• Banca de defesa: Caldas, Jorge Navaes , Pinto, Ricardo Rodrigues da Cunha , Gil, Rosane Aguiar da Silva San
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Engenharia Química
• Departamento: Centro de Tecnologia e Ciências::Instituto de Química
• País: BR
• Palavras-chave em Português: Adsorção; compostos nitrogenados; compostos sulfurados; diesel; banho agitado
• Palavras-chave em Inglês: Adsorption; nitrogen compounds; sulfur compounds; diesel; stirred tank
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
• Link de acesso: http://www.bdtd.uerj.br/handle/1/11959

Environmental concern is part of the routine of the oil industry. The presence of heterocyclic compounds in diesel cuts induces its removal, because beyond the environmental aspects, those compounds can interfere on hydrotreatment process (HDT) performance. Adsorption process is one of the options for the removal of these heterocyclic compounds to minimize this problem. In this context, the objective of this work was to study the most suitable commercial adsorbent by a kinetic study realized in stirred tank supported by a few equilibrium experiments. We gave emphasis to the nitrogen compounds removal and the most promising adsorbents were also evaluated in terms of the removal of sulfur compounds. The selected adsorbents included commercial ones, bentonitic clays TCO 626G (Süd-Chemie) and F-24 (Engelhard), n γ-alumina CCI (Süd-Chemie), a silica-alumina SIRAL 40 (Sasol) and an ultrastable zeolite Y - USY (given in by CENPES-Petrobras). Quinoline, carbazole and benzothiophene were used in the composition of the "diesel model solution", with n-hexadecane as diluent. The characterization of these adsorbents included chemical analysis by X-ray fluorescence, structural analysis by X-ray diffraction, textural analysis by N2 fisisorption, acidity analysis by temperature programmed desorption of ammonium (TPD-NH3) and infrared spectroscopy of adsorbed pyridine. The kinetic studies showed that quinoline is quickly adsorbed mainly on the USY zeolite, which presented the largest adsorptive capacity. It was observed that the adsorbents capacity depended on the number of strong acid sites found by TPD-NH3: the larger the number of strong acid sites, the better the adsorbent. Concerning kinetic studies with carbazole, USY zeolite was also the best adsorbent. There was no agreement in relation to the acidity, and it was already expected once it is a compound that presents no basicity. The presence of carbazole and quinoline in the same solution didn't alter their kinetic removal performances, probably indicating that they did not compete for the same adsorption sites. When a sulfur compound was introduced in the system, the zeolite remained the best adsorbent, the quinoline was still efficiently removed, but the carbazole removal suffered some interference that might indicate a competition of the molecules for the same adsorption sites. In the studies with real diesel loads, unlike observed for the model solution, TCO 626G was found more effective in heteroatoms removal than USY zeolite. The proposed kinetic model adjusted the curves appropriately and the adsorption isotherms for quinoline and carbazole, related to USY and TCO 626G were better adjusted by Freundlich isotherm model