Stability of CuZnOAl2O3/HZSM-5 and CuFe2O4/HZSM-5 catalysts in dimethyl ether steam reforming operating in reaction-regeneration cycles
Ver/
Fecha
2014-05-21Autor
Oar Arteta, Lide
Remiro Eguskiza, Aingeru
Vicente, Jorge
Bilbao Elorriaga, Javier
Gayubo Cazorla, Ana Guadalupe
Metadatos
Mostrar el registro completo del ítem
Fuel Processing Technology 126 : 145-154 (2014)
Resumen
The study focuses on the regenerability of bifunctional catalysts prepared with different metallic functions (CuZnOAl2O3 and CuFe2O4 spinel) and HZSM-5 zeolite (SiO2/Al2O3 = 30) as the acid function. These catalysts have been employed for H2 production in the steam reforming of dimethyl ether in a fluidized bed reactor, operating in reaction-regeneration cycles. The regeneration of the catalysts was carried out by combustion in air (temperature range of 315-500 ºC) of the deposited coke, in order to establish: i) the coke combustion temperature required for recovering the activity of the metallic and acid functions; and ii) the kinetic behaviour of the catalysts after removing the coke deposited on the metallic function and after the complete removal of coke. The coke combustion is selective and at 315 ºC only the coke deposited on the metallic sites is burned, whereas 500 ºC are required to remove the coke deposited on the zeolite. It has been proven the higher stability of the catalyst with CuFe2O4 spinel metallic function, which allows operating uninterruptedly under reaction-regeneration cycles, since it recovers its activity after regeneration at 500 ºC (necessary for the combustion of the coke deposited on the zeolite). The catalyst with CuZnOAl2O3 metallic function, which is more active than the Cu-Fe spinel for the dymethyl ether steam reforming, deactivates irreversibly at 500 ºC due to Cu sintering.