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Nickel on alumina support offers opportunity for gasification of biomass for hydrogen production. In a recent contribution from our research team, (González Castañeda, D. G., et al. 2019) showed that cerium or lanthanum co-impregnation at 2 wt% with nickel may have a favorable effect for biomass catalytic gasification. However, and given an observed influence of lanthanum on the formation of small Ni crystallite sizes, five Ni/γ-Al2O3 based fluidizable La promoted catalysts were studied. Nickel-alumina catalysts promotion was effected varying La in the 0.5 and 1.0 wt% range. Once impregnation precursors loaded, they were reduced at 480 °C via an activation step. Catalysts were characterized using BET, XRD, AA, TPR, TPD, H2-chemisorption, TEM-EDX and FTIR. Catalyst performance was established in a fluidized CREC Riser Simulator, using: a) glucose as surrogate biomass, b) 600 °C, c) steam/biomass (S/B) ratio of 1, d) catalyst /biomass (C/B) ratio of 3.2 and e) 20 s reaction time. Data obtained was analyzed using an ANOVA statistical data analysis package with the 5 wt% Ni and 0.5–1 wt% La and Ce on γ-Al2O3 catalysts, prepared using a pH of 1 of impregnating solution were the best yielding 0.53–0.56 hydrogen molar fractions. These catalysts also gave a 39% reduced coke, and this while compared with the coke formed on the 2% Ce – 5 wt%Ni/γ-Al2O3 (González Castañeda, D. G., et al. 2019). This promising performance was assigned to the dominant NH3-TPD medium acidity, the high catalyst specific surface (∼140 m2/g), and the good 9% metal dispersion with 9–10 nm nickel crystallites.

Six different Ni-based fluidizable catalysts were synthesized using both incipient impregnation and co-impregnation. Ni-based catalysts were also promoted with 2.0 wt% La or alternatively with 2 wt% Ce. The preparation procedure included catalysts treated at high temperatures and under free of oxygen conditions. Catalysts were characterized using BET, XRD, AA, PSD, TPR, TPD, H2-chemisorption. TPR and H2 chemisorption showed good metal dispersion with 10 nm- 40 nm metal crystallites. Glucose catalytic gasification runs were performed in a CREC Riser Simulator to evaluate the following catalysts: (a) 5 %Ni/γ-Al2O3, (b) 5 %Ni-2 %La/γ-Al2O3 and (c) 5 %Ni-2 %Ce/γ-Al2O3. In all cases, the preparation steps involved acid solutions with pHs of 1 and 4. In between consecutive runs, different approaches were considered: (a) A catalyst was regenerated by air, (b) A catalyst was regenerated by air followed by hydrogen pretreatment, (c) A catalyst was reused directly without any regeneration or hydrogen pretreatment. It was observed that Ni-based catalysts, which were subjected after every run, to both, air regeneration and hydrogen pretreatment, displayed the best yields in close agreement with thermodynamic equilibrium. On the other hand, Ni-based catalysts regenerated with air only, showed the worst hydrogen yields. In between these two-hydrogen yield limits, where catalysts not contacted with air nor hydrogen, with these yields being moderately below chemical equilibrium. This shows that Ni-based fluidizable catalysts can perform on stream for extended periods, requiring limited reactivation with air and H2. This makes of gasification using the catalysts of the present study, a viable process alternative that could be implemented at industrial scale.