Banca de QUALIFICAÇÃO: ARIKLÊNIO ALVES DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : ARIKLÊNIO ALVES DA SILVA
DATA : 30/09/2019
HORA: 14:30
LOCAL: Auditório do NUPPRAR
TÍTULO:

Iron and nickel based oxygen carriers for application in the chemical looping reforming of methane process

PALAVRAS-CHAVES:

Greenhouse gases, CLR, Methane, Iron, Nickel.

PÁGINAS: 87
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

Since the advent of industrialization, global energy demand has considerably grown due to industrial and technological modernization as well as population growth. Thus, anthropogenic emissions of greenhouse gases from the burning of fossil fuels have taken great proportions. Among fossil fuels, methane and carbon dioxide are the major contributors to the rise in global temperature. Thus, energy production processes that release smaller amounts of these gases into the atmosphere have been the target of studies in recent years. Among these processes, Chemical Looping Reforming (CLR) od methane has gained attention because, through this process, methane is converted into synthesis gas, a mixture of carbon monoxide and hydrogen, without the release of CO2. Moreover, hydrogen is a clean combustion energy source, meaning it does not release pollutants into the atmosphere, since its burning results in only water and heat. The efficiency of the CLR process lies in the development of an efficient solid oxygen carrier, which is a metal oxide-based material that promotes the conversion of fuel into its reaction products. Based on this, this master's thesis aims to synthesize and characterize iron and nickel-based solid oxygen carriers supported in calcium aluminate and to evaluate the most promising to be applied in CLR processes. Calcium aluminate support was synthesized from chicken eggshell, a calcium source residue; then, iron and nickel were impregnated in this support through the incipient wetness impregnation technique, in order to obtain 4 oxygen carriers: one with iron only, one with nickel only and two containing iron and nickel in different proportions. Oxygen carriers were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), temperature programmed reduction (TPR), scanning electron microscopy (SEM) and reactivity by thermogravimetry techniques. Through XRD results, CaFe2O4 and FeAl2O4 phases were identified as the most reactive for iron-based oxygen carriers and NiO phase for nickel-containing oxygen carriers. Additionally, SEM images of the oxygen carriers showed fine dispersion of the active phases on the support surface and no apparent signs of sintering were found. From the reactivity tests by thermogravimetry it was observed that the oxygen carriers presented the capacity of reduction and oxidation in successive chemical cycles using methane, being possible to obtain a minimum of 90% of solids conversion in time intervals less than 1 minute. The evaluated materials are suitable for application in CLR processes, especially those containing iron and nickel in different proportions in their composition.

MEMBROS DA BANCA:
Presidente - 349770 - DULCE MARIA DE ARAUJO MELO
Externa à Instituição - ELANIA MARIA FERNANDES SILVA - UFRN
Externo à Instituição - RODOLFO LUIZ BEZERRA DE ARAÚJO MEDEIROS - UFRN