Enhanced Reforming of Tar Based on Double-Effect Ni/CaO–Ca12Al14O33 Catalysts: Modified by Ce, Mg, and Fe

The double-effect Ni-based catalysts, modified with Ce, Mg, and Fe and synthesized by the coprecipitation method, were applied into the enhanced steam reforming process of real tar. The effects of the catalysts with different doping mass proportions (3, 6, 9, and 12%) of Ce, Mg, and Fe on the H2 yield, and H2 and CO2 concentrations were studied. The results revealed that the tar reforming efficiency was improved with appropriate proportions of the additives added. The Ce- or Mg-doped catalyst could change the distribution or morphology of the active component Ni. The modified catalyst with 6% Ce or 3% Mg doping showed the best catalytic activity in the reforming experiment, with the H2 yield reaching 86.84% or 85.22%, respectively. The Fe-doped catalyst could form an Ni–Fe alloy and improve the stability of the catalyst, and the better catalytic activity can be obtained at 9 and 12% Fe doping, with the H2 yield reaching 85.54 and 85.80%, respectively