Synthesis of Ni/Al₂O₃/CaO Composite Catalyst for Hydrogen Production by Steam Reforming of Ethanol

Improving the steam reforming of ethanol by Ni/Al2O3/CaO composite was investigated in this work. The CO2 sorbent plays a key role in the catalytic reaction enhancement. The reforming catalysts were prepared by the as-prepared 10 wt.% Ni/Al2O3 physical mixing with CaO sorbents (from Ca(OH)2 conversion). All reforming experiments were performed under 873K condition. In addition, the suitable parameters of mass ratio of Ni catalyst/CO2 sorbent (20 : 80 w/w) and steam/ethanol molar ratio of five were adjusted in this work. The results indicate that the steam reforming of ethanol via CO2 sorption enhancement obviously produced ∼95% H2 greater than common steam reforming of ethanol (∼72% H2). Other by-products involving CO2, CO and CH4 can be also obviously suppressed during reaction. For the sorption-enhanced steam reforming, the recyclability of CO2 sorbent is an important issue. The 10 cycles of reaction/regeneration at 873K and 1023K for the steam reforming of ethanol were tested. The results reveal the H2 concentration of products stably keeps above 90% during the cycles test. The performance of CO2 sorbent was insignificant change after 10 cycles. The average capture capacity of CO2 around 17.8 wt.% can be determined during cycles.