Abstract
Combined steam and CO2 reforming (CSDR) of bio-oil enables the joint valorization of CO2 and a biomass derivative for the sustainable production of syngas. This work studies the influence of calcination temperature (600, 725, and 850°C) of the Ni(15 wt%)/MgAl2O4 catalyst on its properties, catalytic behavior and regenerability in the CSDR of raw bio-oil. Reaction-regeneration cycles were carried out under the following reaction conditions: 700°C, atmospheric pressure, CO2/C molar ratio = 0.54, steam to carbon molar ratio (S/C) = 0.38 (corresponding to the water contained in the bio-oil), and weight bases space time (= 0.38 h. Regeneration consisted of oxidation (with air) followed by reduction (H2(10%)/N2), both stages carried out at 850 °C (for 3 hours). The results show that increasing the calcination temperature decreases metal dispersion and initial activity, but improves the stability and quality of the synthesis gas (H2/CO molar ratio > 1), with the catalyst calcined at 725 °C offering the best balance between activity, stability, and syngas quality. Regeneration at 850°C effectively removes coke (during combustion with air) and promotes the redispersion of Ni (in the subsequent reduction to obtain the active Ni0 phase), allowing the initial activity to be recovered. However, there is a slight increase in deactivation rate, resulting in reproducible behavior after the second reaction cycle for high calcination temperatures.
