Sistemas magnéticos nanoestruturados para a remoção seletiva de compostos sulfurados e nitrogenados do petróleo

Abstract

In this work, it has been developed new magnetic amphiphilic composites based on three inorganic matrix partially covered with carbon. Different matrix were investigated: iron oxide (α-Fe2O3), nickel oxide (NiO) and bentonite clay and they were submitted to a chemical vapor deposition process (CVD) to growth carbon nanotubes/nanofibers on their surfaces using ethanol as carbon source. The obtained materials were characterized and applied in removal of sulfur and nitrogen compounds present in petroleum derivative fuels and degradation reactons of textile dyes. Chapter 1 describes a general introduction about sulfur and nitrogen removal from fuels. Also, it was presented important aspects of magnetic materials and inorganic matrix used in this work. Furthermore, the aims of this work were also presented in this chapter. The experimental data were exhibited in Chapter 2. In Chapter 3, the hematite and bimetallic compound of iron and molybdenum were applied to CVD process. Analysis showed that the metals are reduced by ethanol forming carbon on the surface of materials. There possible to observe a higher deposition of carbon on the molybdenum materials, with maximum deposition of 29%. The materials were active in the oxidation reactons of methylene blue, with maximum discoloration of 89% and 55% of total organic carbon (TOC) removal for the material FeMo/C900. The biphasic oxidation reactions showed good results in the oxidation of sulfur and nitrogen contaminants fuel with maximum removal of 62% DBT in the presence of the material FeMo/C700 and almost 100% for QN oxidation in the presence of FeMo/C900 material. Contact angle measurements and emulsion formation tests was made to study the stability of biphasic systems in which all the materials were able to form an emulsion of oil in water or water in oil. Chapter 4 presents the results obtained for the materials prepared from nickel oxide and bimetallic compounds of nickel and molybdenum covered partially with carbon. It was observed 48% of maximum deposition of carbon in the material NiMo/C800. The materials were also tested in oxidation reactions of methylene blue where both series showed good results, with 80% of discoloration in the presence of the material NiMo/800. The biphasic oxidation reactions in the presence of materials showed good results, with maximum removal of 82% of DBT and 96% of QN in the presence of NiMo/C800 material. Contact angle measurements and tests of emulsion formation was made to study the stability of two-phase systems. In Chapter 5 it is shown the results obtained using bentonite impregnated with iron, subjected to the CVD process with ethanol. It is observed reduced iron phase with consequent carbon deposition. It have been studied the surface properties of the material concerning to the hydrophilicity and adsorption test of organic matter and nitrogen and sulfur compounds were presented with the maximum adsorption capacity of 38.7% for DBT, 54.5% for QN for the material BAF15/C. Finally, chapter 6 exhibits the general conclusions of this work.