Navegando por Assunto "Aluminum oxide"

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Acesso aberto (Open Access)
Adsorção de CU2+ em alumina de transição obtida a partir da mistura de gibbsita e hidróxido de alumínio gel
(Universidade Federal do Pará, 2015-09-30) PINHEIRO, Darllan do Rosário; MARTELLI, Marlice Cruz; http://lattes.cnpq.br/1213009262936026
Alumina is one of the most important oxides in the ceramic industry, being used mainly in the form of calcined alumina or fused applied, among other ways, as adsorbent material. In this work is a transition alumina production method from a mixture of gibbsite, from the Bayer process, gel and aluminum hydroxide, from the reaction of aluminum sulfate and ammonium hydroxide targeting the application as an adsorbent material for removing Cu2 + in aqueous solution. Adsorption conditions including contact time and pH were investigated. Assays were carried out at 30 ° C and 50 ° C, in which 1 g of alumina produced was subjected to contact with 100 ml of an aqueous solution containing Cu2 +. The concentrations of the aqueous solutions employed were 100, 200, 400, 800, 1600 and 2000 ppm copper sulphate solution. The characterization of copper sulfate solutions was performed in UV spectrophotometry and characterization of the material produced was carried out by XRD, EDX and BET surface area. Evaluated the contact time to achieve the adsorption equilibrium which is optimized time 15 min. The effect of pH on the adsorption shows that the adsorption temperature increases there is an increased pH compared with the pH of the initial solution of copper sulfate. The isotherms of Langmuir and Freundlich had satisfactory results for adsorption, and the Langmuir isotherm that better fits the adsorption data. Through the equilibrium isotherms it was found that the material produced has adsorption capacity for Cu2 + ion.
Acesso aberto (Open Access)
Estudo do processo de craqueamento termocatalítico do óleo de palma (Elaeis guineensis) com lama vermelha calcinada e alumina ativada em reatores de bancada e batelada
(Universidade Federal do Pará, 2015-05-29) LOURENÇO, Rafael Martins; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
In the present work was to study the thermal catalytic cracking process palm oil for biofuel production. In the development of this study were performed in crackings Bench and Semipilot. Initially, basic catalysts in cracking tests were performed (Red Mud; Red Mud Calcined at 550 ° C; Red Mud Calcined at 800C; Red Mud Calcined at 1000 ° C; Activated Alumina (AA) with NaOH 20% solution and Activated Alumina (AA) NaOH solution 30%) and acid (not activated alumina) in bench scale using as raw palm oil. Before the mentioned catalysts are used in thermal catalytics crackings, they were subjected to the following tests: Fourier Transform Infrared (FT-IR); Scanning Electron Microscopy (SEM); X-ray Diffraction (XRD) and BET in order to characterize them. The results of the bench scale showed that the cracked products Gross (PCB's) achieved in thermal catalytics oil crackings using as a catalyst 15% Red Mud Calcined at 800 ° C and 15% AA by NaOH 20% solution, had a significant reduction in their Acidity Index (IA's) compared to the IA's of heat and thermal catalytics crackings used with other catalysts. In Semipilot Scale the thermal catalytics crackings were developed with the best results obtained, Bench Scale, between the Red Mud’s Calcined or not in different concentrations (15% of Red Mud Calcined 800 ° C) and between the Activated Aluminas or not at various concentrations (AA with 15% NaOH solution at 20%) compared to IA's, in addition to the thermal cracking which was also reproduced on the scale. Some of the products obtained in Semipilot Scale was submitted to distillation in Bench Scale to obtain fractions corresponding to the tracks: gasoline, kerosene, light diesel and heavy diesel. The RMN analysis of 13C, held on the heat crackings and diesel thermal catalytic with 15% Red Mud Calcined at 800 °C proves that they are basically formed from long chain fatty acids. Moreover, the GC-MS performed in the cut of gasoline range (40 °C- 175 °C) showed that the three gasolines analyzed showed the formation of paraffinic hydrocarbons, olefinic and naphthenic.