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Previous issue date: 2014-09-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Nos ?ltimos anos, transportadores s?lidos de oxig?nio adequados t?m sido
desenvolvidos para serem utilizados em diferentes processos de Recircula??o Qu?mica.
O sucesso desta tecnologia est? diretamente relacionado com a reatividade qu?mica e a
capacidade de armazenamento de oxig?nio do transportador. Desta forma, a pesquisa no
desenvolvimento de novos materiais que possam ser aplicados ao processo torna-se de
fundamental import?ncia. Entre os poss?veis candidatos est?o os transportadores
baseados em n?quel e cobre por apresentarem propriedades termodin?micas favor?veis.
Neste trabalho, aluminatos do tipo MAl2O4 (M=Mg e Ca) e M0,9B0,1Al2O4 (B=Ni e Cu)
usados como suportes, foram sintetizados pela rea??o de combust?o assistida por microondas
e calcinados a 900?C/2h. Em seguida, os suportes foram impregnados com 10%
(m/m) de n?quel ou cobre e, posteriormente calcinados a 600?C/2h para obten??o dos
transportadores s?lidos de oxig?nio, que foram caracterizados por Difra??o de raios X
(DRX), Microscopia eletr?nica de varredura (MEV) e Redu??o a temperatura
programada (RTP). Rea??es simulando o processo de combust?o por recircula??o
qu?mica foram realizados atrav?s de ciclos de redu??o/oxida??o, com o objetivo de
avaliar a reatividade dos transportadores. A an?lise de DRX mostrou picos de difra??o
de estruturas tipo espin?lio. Nos suportes dopados n?o foram verificadas a presen?a de
fases secund?rias, sugerindo que todo o metal foi incorporado ? estrutura do espin?lio.
Nos transportadores s?lidos de oxig?nio, as fases NiO e CuO foram observadas ap?s a
impregna??o das fases ativas sobre os diferentes suportes. Os resultados das avalia??es
dos ciclos qu?micos de redu??o/oxida??o revelaram que os TSO?s impregnados com
n?quel em diferentes suportes mostraram-se mais ativos, sendo potenciais candidatos
para a aplica??o na tecnologia de Recircula??o Qu?mica. / In recent years, solid carriers suitable oxygen have been developed for use in different
chemical processes recirculation. The success of this technology is directly related to
the chemical reactivity and the oxygen storage capacity of the carrier. Thus, research
into the development of new materials that can be applied to the process becomes
extremely important. Possible candidates are the carriers based on nickel and copper for
presenting favorable thermodynamic properties. In this work, aluminates type MAl2O4
(M = Mg and Ca) and M0,9B0,1Al2O4 (B = Ni and Cu) that are used as supports were
synthesized by combustion reactions assisted by microwave and calcined at 900?C/2h.
Then, the carriers were impregnated with 10% (m/m) of nickel or copper, and
subsequently calcined at 600?C/2h to obtain the solid oxygen carriers, which were
characterized by X-ray diffraction (XRD) Microscopy scanning electron microscopy
(SEM) and temperature programmed reduction (TPR). Reactions simulating the
combustion process by chemical recirculation were performed by cycles
reduction/oxidation, in order to evaluate the reactivity of carriers. XRD analysis
revealed diffraction peaks of the spinel type structures. In the doped substrates were
verified the presence of secondary phases, suggesting that all the metal was
incorporated into the spinel structure. In solid oxygen carriers, the NiO and CuO phases
were observed after impregnation of active phases on different media. The results of
evaluations of chemical cycles reduction/oxidation revealed that TSO's impregnated
with nickel in various media were more active and are potential candidates for use in the
chemical recirculation technology
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/19531 |
| Date | 08 September 2014 |
| Creators | Peres, Ana Paula da Silva |
| Contributors | 06117988320, http://lattes.cnpq.br/3318871716111536, Lima, Andreia Cavalcante de, 02677227452, http://lattes.cnpq.br/7456992068208495, Barros, Br?ulio Silva, 00735018405, http://lattes.cnpq.br/8938691250105531, Pimentel, Patr?cia Mendon?a, 77858239449, http://lattes.cnpq.br/9303372770390061, Braga, Renata Martins, 05165674460, http://lattes.cnpq.br/4603529162393328, Melo, Dulce Maria de Ara?jo |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM CI?NCIA E ENGENHARIA DE MATERIAIS, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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