Navegando por Autor "Benachour, Monhad"
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Artigo Oxidación húmeda de fenoles con catalizadores Fe-CeO2, K-MnO2/ CeO2/Paligorsquita y Fe/ paligorsquita(Centro de Información Tecnológica, 2011) Santiago Júnior, Aristides Felipe; Sousa, João Fernandes de; Benachour, Monhad; Rojas, Leopoldo Osvaldo AlcazarSe ha evaluado el funcionamiento de catalizadores Fe-MnO2/CeO2, K-MnO2/CeO2/Paligorsquita y Fe/Paligorsquita en la degradación oxidativa húmeda del fenol en un reactor de mezcla. Los experimentos se ejecutaron a: temperatura de 130º C, presión de 20.4 atm., concentración másica del catalizador de 5 g/L y concentración inicial del fenol de 0,5 g/L Los parámetros evaluados fueron: contenido de hierro impregnado (0, 3; 7 y 10%, m/m) y el pH inicial del medio reactivo (3.1; 6.8 y 8.7). Las curvas de degradación del fenol indican que el catalizador Fe+2/Paligorsquita tiene un papel preponderante en la conversión de carbono orgánico total comparado con los demás catalizadores. Se encontró también que la disminución de la alcalinidad del medio reactivo favorece la conversión de fenol y que el soporte paligorsquita parece ser más resistente a la acción de los compuestos ácidos formados durante la reacciónArtigo Synthesis and characterization of bifunctional transition-metal/silica-alumina catalysts for the chloromethane conversion to hydrocarbons(ABPG, 2008) Rojas, Leopoldo Osvaldo Alcazar; Nascimento, José Carlos; Ruiz, Juan Alberto Chavez; Benachour, Monhad; Sousa, João Fernandes deIn this work bifunctional (metal-acid) catalysts of Fe, Ni, Fe2O3 and NiO over amorphous silica alumina support were characterized (acidity) and evaluated for the conversion of chloromethane in a fixed bed reactor. Temperature program tests TPD (Temperature Programmed Desorption) and TPR (Temperature Programmed Reduction) were performed to characterize the quimissorption sites for the impregnated and unimpregnated support. New adsorption sites were created on the metal supported catalysts. The conversion yield of chloromethane was evaluated for the five materials. The highest conversion conversion (85%) was observed for the unmodified support (SiAl) after 6 of reaction at 860 K and a WHSV (Weight Hourly Space Velocity) of 4,5 h-1. The best selectivity toward desirable hydrocarbons (C3, C4) was found for the Fe-SiAl catalyst. C3 was also found in the products stream when Ni/SiAl and NiO/SiAl catalyts were tested. Ni catalysts were the most favorable to methane production. The catalytic tests showed coke formation in all materials. For the SiAl support the desorption energy of chloromethane, determined by TPD runs, was 101,9 KJ/mol. The metals presented lower desorption energies (75,2 KJ/mol for Ni and 133,4 KJ/mol for Fe) than the oxides (190,1 KJ/mol for Fe2O3 and 322,4 KJ/mol for NiO)Artigo Total catalytic wet oxidation of phenol and its chlorinated derivates with MnO2/CeO2 catalyst in a slurry(Brazilian Society of Chemical Engineering, 2009-09) Luna, A. J.; Rojas, Leopoldo Osvaldo Alcazar; Melo, Dulce Maria de Araújo; Benachour, Monhad; Sousa, João Fernandes deIn the present work, a synthetic effluent of phenol was treated by means of a total oxidation process-Catalyzed Wet Oxidation (CWO). A mixed oxide of Mn-Ce (7:3), the catalyst, was synthesized by co-precipitation from an aqueous solution of MnCl2 and CeCl3 in a basic medium. The mixed oxide, MnO2/CeO2, was characterized and used in the oxidation of phenol in a slurry reactor in the temperature range of 80-130ºC and pressure of 2.04-4.76 MPa. A phenol solution containing 2.4-dichlorophenol and 2.4-dichlorophenoxyacetic acid was also degraded with good results. A lumped kinetic model, with two parallel reaction steps, fits precisely with the integrated equation and the experimental data. The kinetic parameters obtained are in agreement with the Arrhenius equation. The activation energies were determined to be 38.4 for the total oxidation and 53.4 kJ/mol for the organic acids formed