doctoralThesis
Síntese e caracterização de materiais mesoporosos para a captura de CO2: influência do óxido de níquel
Fecha
2014-09-23Registro en:
NASCIMENTO, Alexsandra Rodrigues do. Síntese e caracterização de materiais mesoporosos para a captura de CO2: influência do óxido de níquel. 2014. 125f. Tese (Doutorado em Engenharia Química) - Centro de Tecnologia, Universidade Federal do Rio Grande do Norte, Natal, 2014.
Autor
Nascimento, Alexsandra Rodrigues do
Resumen
Several materials are currently under study for the CO2 capture process, like the metal
oxides and mixed metal oxides, zeolites, carbonaceous materials, metal-organic frameworks
(MOF's) organosilica and modified silica surfaces. In this work, evaluated the adsorption
capacity of CO2 in mesoporous materials of different structures, such as MCM-48 and SBA-
15 without impregnating and impregnated with nickel in the proportions 5 %, 10 % and 20 %
(m/m), known as 5Ni-MCM-48, 10Ni-MCM-48, 20Ni-MCM-48 and 5Ni-SBA-15, 10NiSBA-15,
20Ni-SBA-15. The materials were characterized by means of X-ray diffraction
(XRD), thermal analysis (TG and DTG), Fourier transform infrared spectroscopy (FT-IR), N2
adsorption and desorption (BET) and scanning electron microscopy (SEM) with EDS. The
adsorption process was performed varying the pressure of 100 - 4000 kPa and keeping the
temperature constant and equal to 298 K. At a pressure of 100 kPa, higher concentrations of
adsorption occurred for the materials 5Ni-MCM-48 (0.795 mmol g-1
) and SBA-15 (0.914
mmol g-1
) is not impregnated, and at a pressure of 4000 kPa for MCM-48 materials (14.89
mmol g-1) and SBA-15 (9.97 mmol g-1) not impregnated. The results showed that the
adsorption capacity varies positively with the specific area, however, has a direct dependency
on the type and geometry of the porous structure of channels. The data were fitted using the
Langmuir and Freundlich models and were evaluated thermodynamic parameters Gibbs free
energy and entropy of the adsorption system