Dessulfurização adsortiva de combustíveis utilizando ZSM-35 impregnada com molibdênio

• Ano de defesa: 2020
• Autor(a) principal: Correia, Iara Michelle Silva
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio Grande do Norte; Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM ENGENHARIA QUÍMICA
• Palavras-chave em Português: Dessulfurização adsortiva; Cinética de adsorção; Molibdênio; ZSM-35
• Link de acesso: https://repositorio.ufrn.br/handle/123456789/47009

The search for cleaner technologies for the removal of sulfur compounds in fuels is a constant, since the commercial desulphurization process currently used is characterized by high hydrogen consumption and severe temperature and pressure operating conditions, in addition to not meeting the future demands of environmental legislation. In this work was evaluated the alternative use of zeolite ZSM-35 modified with molybdenum was evaluated in different concentrations (2.5%, 5%, 10% w/w) and applied in an adsorptive desulfurization process at low temperature and pressure. The materials were prepared by wet impregnation and characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), thermal analysis (TG/DTG) and scanning electron microscopy (SEM). The adsorptive desulfurization was carried out in a batch system at temperatures ranging from 30 ° C to 50 ° C under a constant stirring of 140 rpm using a model fuel containing 800 ppm of sulfur. The sulfur contained in the samples was quantified according to the ASTM D5443 standard. The adsorption kinetics was evaluated by the kinetic models of pseudo-first order, pseudo-second order, intraparticle diffusion and Elovich. The results showed that the adsorbents obtained had their structures little affected by the metallic impregnation process and that the thermal stability of the adsorbents was affected by the concentration of molybdenum in the structure, with the lowest mass loss observed being 11,4% (2,5MZ35 sample). In the adsorption desulfurization process for the evaluated systems, the yield varied from 9,53% (2.5% Mo at 30 ° C) to 22,28% (10% Mo at 50 ° C) and that the capacity of adsorption was influenced by temperature and metal concentration in the zeolitic structure. In general, the pseudo-second order kinetic model best represented the adsorption process. The adsorbents obtained showed a good potential for application in desulphurization processes of fuels by adsorption.