Banca de QUALIFICAÇÃO: TIAGO ROBERTO DA COSTA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : TIAGO ROBERTO DA COSTA
DATA : 11/07/2016
HORA: 14:00
LOCAL: Auditório do NUPPRAR
TÍTULO:

TRANSPORTADORES DE OXIGÊNIO A BASE MANGANÊS PARA UTILIZAÇÃO EM PROCESOS DE COMBUSTÃO COM RECIRCULAÇÃO QUÍMICA

PALAVRAS-CHAVES:

Capture of CO₂, Oxygen Carrier, Chemical-Looping Combsution, Manganese, CLC.

PÁGINAS: 140
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

The world’s energy matrix is essentially composed of fossil fuels. Studies have indicated that in the next decades there will be no significant changes in this scenario, which impacts significantly on the environment, since the burning of fossil fuels for power generation produces great amount of CO₂. Besides, carbon dioxide is the main anthropogenic gas responsible for intensifying greenhouse effect. Because of this, scientists and politicians around the world have suggested a number of strategies and technologies to reduce CO₂ emissions in the atmosphere for the next decades. Among the technologies, CO₂ capture and storage (CCS) has gained attention in recent years. Studies by both the International Energy Agency (International Energy Agency) and the Intergovernmental Panel on Climate Change (IPCC) suggest various economic growth scenarios and energy demand, indicating that in most cases the CO₂ capture and storage technologies will contribute between 10-55% of the global effort to reduce CO₂ concentrations in the atmosphere by 2100. In this context, the Chemical-Looping Combustion is considered one of the best alternatives to reduce the cost of CO₂ capture, especially when compared to conventional capture processes, since it is not necessary the separation of  CO₂ from N₂, and also no need for using pure O₂, because fuel is not mixed directly with air or oxygen. On the other side, also does not occur NO_x formation and the energy involved in the process is the same as a conventional combustion.

This doctoral thesis is focused on the development of five oxygen carriers based of manganese, which were first characterized in order to determine which of them are most promising to be evaluated in CLC processes. The techniques and characterization methods used during the first stage were: porosimetry mercury, fracture resistance, X-ray diffraction (XRD), temperature programmed reduction and oxidation  (TPR and TPO), oxygen transport capacity (Roc), chemical composition, reactivity by thermogravimetry and rate index. Completed these steps, it was found that the carriers Mn-Mn-ZrMF and ZrSG had appropriate properties to be evaluated in a batch fluidized bed reactor, where the experiments are similar to the conditions CLC. After testing the reactor, the oxygen carriers were submitted to some characterization techniques: DRX, TPR and SEM (Scanning Electron Microscopy). The Mn-carrier ZrMF presented problem agglomeration during testing the reactor, therefore discarded. On the other side, the Mn-ZrSG showed high reactivity with the fuels used (CO> H₂> CH₄) not being observed the problem of agglomeration, having low attrition, with an average lifetime exceeding at 11000 hours.

MEMBROS DA BANCA:
Presidente - 349770 - DULCE MARIA DE ARAUJO MELO
Externo ao Programa - 051.656.744-60 - RENATA MARTINS BRAGA - UFRN
Interno - 1308577 - SIBELE BERENICE CASTELLA PERGHER