Industrial & Engineering Chemistry Research, Vol.54, No.45, 11285-11294, 2015
Behavior of a CuFe2O4/gamma-Al2O3 Catalyst for the Steam Reforming of Dimethyl Ether in Reaction-Regeneration Cycles
The kinetic behavior of CuFe2O4/gamma-Al2O3 bifunctional catalyst is studied in the steam reforming of dimethyl ether (SRD) under reaction-regeneration cycles in a fluidized-bed reactor, in the 200400 degrees C range for the reaction step and with coke combustion with air at 500 degrees C for the regeneration step. Results in the SRD process show that, in order to attain a reproducible and active behavior of the catalyst in successive reaction-regeneration cycles, a previous equilibrating treatment is required, consisting of a steam reforming reaction under high coke deposition conditions and subsequent coke combustion. Characterization results of the catalyst subjected to different treatments reveal that the equilibration and high activity of the catalyst are a consequence of the following structural changes: (i) the presence of water in the reaction medium gets the metallic copper redispersed within the spinel matrix; and (ii) coke deposition, followed by its combustion, is responsible for the structural change of the spinel from tetragonal to cubic and the redispersion of the spinel on the gamma-Al2O3 acid function.