Manganese oxide dissociation kinetics for the Mn2O3 thermochemical water-splitting cycle. Part 1: Experimental
2010; Elsevier BV; Volume: 65; Issue: 12 Linguagem: Inglês
10.1016/j.ces.2010.03.002
ISSN1873-4405
AutoresTodd M. Francis, Paul Lichty, Alan W. Weimer,
Tópico(s)Carbon Dioxide Capture Technologies
ResumoIt is shown that the dissociation of Mn2O3 to MnO in a short residence time aerosol flow reactor can achieve high conversions approaching 75% when the concentration of oxygen is kept below 0.25%. Significant recombination reaction occurs when the oxygen content exceeds ∼0.25% by volume. A dual reaction mechanism for Mn2O3 dissociation was found: RAvrami−Erofeev=−A1e−Ea,1/RTn(1−X)[−ln(1−X)](n−1)/nROrder_of_reaction=−A2e−Ea,2/RT(1−X)n with the transition from one mechanism to the other occurring at an extent of reaction of approximately 0.6. Rate constants for the two mechanisms were calculated to be 1.8×107±1.3×107 and 5.6×103±4.1×103 s−1, respectively, for oxygen concentration<0.25%. High levels of dissociation are achievable when the reaction is carried out in an inert gas environment using a reactor configuration that limits the reverse reaction.
Referência(s)