Banca de QUALIFICAÇÃO: RAFAEL VIANA SALES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAFAEL VIANA SALES
DATE: 17/03/2020
TIME: 14:00
LOCAL: auditório do Química III
TITLE:

ADSORTIVE  PERFORMANCE  OF  MOLECULAR  SIEVES  DEVELOPED  FOR  DEEP DESULFURIZATION OF DIESEL FUEL

 

KEY WORDS:

Desulphurization;Adsorption;Photo-oxidation;MCM-41;MPIsilica;KIT-6;Cu-BTC.

PAGES: 100
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

The emission of sulfur compounds from the burning of fossil fuels has received great attention from the scientific community, which has concentrated its efforts on solving problems related to environmental pollution and industrial costs. In this work, chemical interactions between metal particles (Ag or Ni) dispersed in low cost MCM-41 produced from beach sand (amorphous silica MP1) and sulfur compounds were evaluated in adsorptive desulfurization process of real diesel fuel. N2 adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM) scanning transmission electron microscopy coupled to energy-dispersive X-ray spectroscopy (STEM-EDX) were used to characterize the adsorbents. The results provided a high dispersion of different Ag nanodomains on the MCM-41 support. The best fit of the kinetic and equilibrium data to the pseudo-second order and Langmuir models, respectively, show the occurrence of chemoreaction interactions with organosulfur compounds. Thermodynamic tests indicated that adsorption of sulfur compounds on Ag/MCM-41 occurs via an endothermic process under the conditions studied. The magnitude of ∆H indicates that chemosortive mechanisms govern sulfur removal. Molecular dynamics simulation performed by DFT/ONIOM method and X-ray photoemission spectroscopy (XPS) data were employed to study the adsorbate-adsorbent interaction system in diesel desulphurization over Ag/MCM-41. The computational modeling approach provided valuable information on understanding the molecular level of the mechanism in the adsorption of sulfur aromatic compounds on functionalized MCM-41 and the role of Ag species in this process. In addition, Ti/Cu-BTC/KIT-6 hybrid material was developed and its potential for photocatalytic oxidative degradation of dibenzothiophene in a combined liquid-liquid extraction process was studied. Airflow was used as oxidizing agent and the procedure was conducted under UV radiation. Ti/Cu-BTC/KIT-6 as well as Cu-BTC, KIT-6 and Cu-BTC/KIT-6 analogs were characterized by X- ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG/DTG), textural analysis by the BET/BJH method and scanning electron microscopy with dispersive energy spectroscopy (SEM-EDS). Kinetic studies were performed and the desulphurization performance was practically stable after 4 regeneration cycles.

BANKING MEMBERS:
Presidente - 1805556 - LUCIENE DA SILVA SANTOS
Interno - 1859346 - MIGUEL ANGELO FONSECA DE SOUZA
Interna - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Externo ao Programa - 2302898 - ELEDIR VITOR SOBRINHO
Externa à Instituição - ANNE GABRIELLA DIAS SANTOS - UERN
Externo à Instituição - VINÍCIUS PATRÍCIO DA SILVA CALDEIRA - UERN