Tese
Emprego de ultrassom para a oxidação e separação de compostos orgânicos sulfurados em hidrocarbonetos e determinação de enxofre por técnicas espectrométricas e cromatográficas
Fecha
2009-04-13Registro en:
DUARTE, Fábio Andrei. Feasibility of ultrasound for oxidation and separation of organosulfur compounds in hydrocarbons and sulfur determination by spectrometric and chromatographic techniques. 2009. 76 f. Tese (Doutorado em Química) - Universidade Federal de Santa Maria, Santa Maria, 2009.
Autor
Duarte, Fábio Andrei
Institución
Resumen
In this work, a process based on ultrasonic energy for sulfur removal from
petroleum fractions was proposed. The process combines ultrasonic energy and a
peroxyacid reagent in order to achieve the required sulfur content recommended by
current regulations for fuels. Studies for ultrasound-assisted oxidative (UAOD)
procedure were performed in a hydrocarbon fraction obtained from petroleum
distillation and dibenzothiophene was used as model sulfur compound. Parameters
for UAOD procedure as ultrasonic irradiation time, ultrasonic amplitude, oxidizing
reagents amount, kind of acid and the solvent for extraction step were investigated.
Sulfur removal was about 95% after only 9 min of ultrasonic irradiation (20 kHz,
750 W, 40% of amplitude) using H2O2 and acetic acid, followed by extraction with
methanol, with oil recovery higher than 95%. The proposed process using ultrasound
allows higher removal efficiency in comparison with the experiments performed under
the same conditions, however using mechanical stirring. The quantification and
identification of sulfur compounds, performed in order to establish the removal
efficiency as well as to evaluate the products obtained by UAOD process, were
carried out using both spectrometric and chromatographic techniques. Inductively
coupled plasma optical emission spectrometry, ultraviolet fluorescence and gas
chromatography (equipped with pulsed flame photometric detector and mass
spectrometry) were used for total sulfur and sulfur compounds determination. In
general, the proposed process needs low reagents consumption and it can be
performed in less time than conventional procedures, without the necessity of high
temperature and pressure or metallic catalysts.