Zeólita ZSM-5 mesoporosa como adsorvente para remoção de contaminantes presentes em água produzida de petróleo

• Ano de defesa: 2022
• Autor(a) principal: Migliorin, Lorenzo da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; Engenharia Química; UFSM; Programa de Pós-Graduação em Engenharia Química; Centro de Tecnologia
• Palavras-chave em Português: Água produzida de petróleo; Ácido naftênico; Zeólita; Adsorção; Oil produced water; Naphthenic acid; Zeolite; Adsorption; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/33472

This work evaluated the synthesis of mesoporous zeolite ZSM-5 used in the batch adsorption of cyclohexane carboxylic acid, an example of naphthenic acid, an organic compound present dissolved in water produced from petroleum. For the generation of mesoporosity of the synthesized ZSM-5 zeolite, sodium alginate was used, in order to increase the pore size of the material, which was later completely removed by calcination in a muffle furnace at 600°C for 10 hours. Subsequently, the mesoporous ZSM-5 zeolite samples were characterized by means of XRD, FTIR, SEM and BET analysis. Through XRD analysis, it was possible to observe that the zeolites obtained presented the typical MFI structure. The structural characteristics of the modified zeolite were improved by adding the mesoporosity agent, obtaining a surface area of 235.58 m2 g-1 with a total pore volume of 0.125 cm3 g-1. The morphological structure of the surface was highly irregular with the presence of several cavities and bumps, scattered randomly across the surface. Functional groups are characteristic of structures containing Si and Al atoms, with a high degree of crystallinity, related to organized and three-dimensional arrangements. The response surface methodology was used indicating that the adsorbent dosage of 3 g L-1 and pH 4 is the minimum optimal condition, obtained from the development of the experimental design methodology Central Composite Rotational Design (DCCR). The adsorption isotherms showed that the adsorption capacity was impaired by the increase in temperature, decreasing from 195 mg g-1 to 140 mg g-1 with increasing temperature in the system, with 298 K being the best temperature. The best statistical fit for the isothermal data was obtained by the Redlich-Peterson model. The adsorption enthalpy (ΔH0 = -92.34 kJ mol-1) corroborated the adsorption process as exothermic being governed by physical interactions. Kinetic studies showed that, regardless of concentration, the system reached equilibrium in the first 50 minutes with maximum capacities of 33.4, 84.8, 140.2 and 195.5 mg g-1 for concentrations of 100, 250, 500 and 1000 mg L-1, respectively. The LDF model was able to describe the adsorption of naphthenic acid on ZSM-5. Still, it was evidenced that the parameters (kLDF and DS) tend to increase with the initial concentration of oil water. In analyzing the adsorption of NA from the real oil-produced water sample, 7 g L-1 of mesoporous ZSM-5 was sufficient to remove 92% of this adsorbate. Therefore, mesoporous ZSM-5 zeolite was successfully synthesized and later used as an adsorbent material with high removal of naphthenic acid from petroleum water.