Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-04T20:02:52Z No. of bitstreams: 1 AnaPaulaDaSilvaPeres_TESE.pdf: 6039953 bytes, checksum: dab3721993c73bd25b03fa484535a768 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-05T20:52:08Z (GMT) No. of bitstreams: 1 AnaPaulaDaSilvaPeres_TESE.pdf: 6039953 bytes, checksum: dab3721993c73bd25b03fa484535a768 (MD5) / Made available in DSpace on 2016-01-05T20:52:08Z (GMT). No. of bitstreams: 1 AnaPaulaDaSilvaPeres_TESE.pdf: 6039953 bytes, checksum: dab3721993c73bd25b03fa484535a768 (MD5) 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