Hydrogen production by ethanol steam reforming over multimetallic RhCeNi/Al2O3 structured catalyst. Pilot-scale study

A new multimetallic RhCeNi/Al2O3 catalyst structured in cylindrical pellet with an atomic ratio Ce/Ni = 0.55 and minimal Rh content was developed and tested in ethanol steam reforming (ESR) at laboratory and semi-industrial pilot plant scales. A beneficial interaction for the major components, Ce-Ni, is noticed. Ce is mostly present as Ce4+ and Ce3+ and the incorporation of small amount of Ni2+ species into the ceria fluorite-type structure is registered since an oxygen coordination disorder was induced by the Ni2+ dissolution that modifies the average size of particles. RhCeNi catalyst is active in the ESR even at different steam/ethanol ratio between 4 and 10 at laboratory scale and is also very active and stable at pilot-plant scale tested at S/EtOH ratio = 7, with a high H2-yield (95% at 700 °C) and minimal presence of secondary products as acetone or ethylene and ethane. CO selectivity is maintained below of 5-7% in the reformer gas-out stream, although it is further reduced to reach acceptable values after WGS and CO-PROX-units to feed the PEM located downstream of the installation.