@InProceedings{SantosCrCaMoFeRo:2013:EfAdSt,
               author = "Santos, Pedro Henrique Lopes Nunes Abreu dos and Cruz, Gilberto 
                         Marques da and Carneiro, Livia Melo and Moure, Gustavo T. and 
                         Ferreira, Marco Aur{\'e}lio and Rodrigues, Jose Augusto Jorge",
          affiliation = "{} and {} and {Instituto Nacional de Pesquisas Espaciais (INPE)} 
                         and Petrobras and {Instituto Nacional de Pesquisas Espaciais 
                         (INPE)} and {Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Effect of adding steam to CH4 during chemical-looping processes 
                         with Ni-based oxygen carriers",
            booktitle = "Proceedings...",
                 year = "2013",
                pages = "1--10",
         organization = "Congresso Brasileiro de CO2. na Ind{\'u}stria de Petr{\'o}leo, 
                         G{\'a}s e Biocombust{\'{\i}}veis, 2.",
             keywords = "Chemical Looping Combustion, CLC, Chemical Looping Reforming, CLR, 
                         oxygen carrier.",
             abstract = "The chemical-looping combustion (CLC) and chemical-looping 
                         reforming (CLR) processes allow combustion to take place in fuel 
                         gases such as CH4 to generate energy and produce H2, impeding the 
                         emission of CO2 into the atmosphere and contributing to greenhouse 
                         mitigation. In this work, the effect of adding water steam to CH4 
                         was investigated, using NiO/alpha-Al2O3 and NiAl2O4/gamma-Al2O3 as 
                         oxygen carriers in order to reduce or eliminate the formation of 
                         carbon deposits on these materials when using long reductions 
                         steps. After characterizing the oxygen carriers using different 
                         techniques, they underwent many redox sequences, proving 
                         themselves to be stable. However, when CH4 was employed as the 
                         only active component of the reaction mixture in argon, large 
                         carbon deposits were formed on both carriers. The carbon deposits 
                         were only removed by a subsequent oxidation step using oxygen in 
                         argon. In experiments carried out in which water steam was added 
                         to the CH4 during the reduction step, carbon deposits on 
                         NiAl2O4/gamma-Al2O3 were almost eliminated and on NiO/alpha-Al2O3 
                         were totally eliminated. Since the results were different, two 
                         different reaction mechanisms were proposed: the first in which 
                         the addition of H2O impeded the formation of carbon deposits and 
                         the second in which the carbon formed was gasified by the water. 
                         Both of the mechanisms were evaluated thermodynamically and 
                         experimentally for each of the steps involved. It can be asserted 
                         that in the case of the NiO/alpha-Al2O3 oxygen carrier, the second 
                         mechanism is much more probable since it involves quick and 
                         irreversible steps and in which water steam acts directly on the 
                         carbon deposits. In the case of the NiAl2O4/gamma-Al2O3 carrier, 
                         both of the mechanisms are possible. Because they involve 
                         reversible reactions they dont result in the total elimination of 
                         carbon deposits, though the level of elimination is quite high.",
  conference-location = "Rio de Janeiro",
      conference-year = "abril de 2013",
                label = "lattes: 9823109938173087 1 SantosCrCaAuAu:2013:EfAdSt",
             language = "en",
           targetfile = "EFFECT OF ADDING STEAM.pdf",
        urlaccessdate = "01 maio 2024"
}