Syngas production from glycerol-dry(CO2) reforming over La-promoted Ni/Al2O3 catalyst

Abstract

A 3 wt% La-promoted Ni/Al2O3 catalyst was prepared via wet co-impregnation technique and physicochemically-characterized. Lanthanum was responsible for better metal dispersion; hence higher BET specific surface area (96.0 m2 g−1) as compared to the unpromoted Ni/Al2O3 catalyst (85.0 m2 g−1). In addition, the La-promoted catalyst possessed finer crystallite size (9.1 nm) whilst the unpromoted catalyst measured 12.8 nm. Subsequently, glycerol dry reforming was performed at atmospheric pressure and temperatures ranging from 923 to 1123 K employing CO2-to-glycerol ratio from zero to five. Significantly, the reaction results have yielded syngas as main gaseous products with H2:CO ratios always below than 2.0 with concomitant maximum 96% glycerol conversion obtained at the CO2-toglycerol ratio of 1.67. In addition, the glycerol consumption rate can be adequately captured using power law modelling with the order of reactions equal 0.72 and 0.14 with respect to glycerol and CO2 whilst the activation energy was 35.0 kJ mol−1. A 72 h longevity run moreover revealed that the catalyst gave a stable catalytic performance.

Efficient hydrogen production from ethanol steam reforming over La-modified ordered mesoporous Ni-based catalysts

“…Combined with the characterization results, it can be clearly observed that the trend of the catalytic performance matches well with that of the active nickel surface areas and nickel metal dispersion. Indeed, the catalytic activity of ESR is highly affected by the amount of Ni sites [75][76][77]. The meso3LaNiAl catalyst exhibits the highest active surface area as shown in Table 1 and hence delivers the highest initial activity.…”

CO2 as an Oxidant for High-Temperature Reactions

“…Siew et al (2014) investigated the performance of Ni/Al 2 O 3 catalysts doped with La for DRG reaction at 873 K. They found that only 3% La promotion was sufficient to reduce the carbon deposition by 20%. This catalyst composition was also found to display good stability over a 72-h test run at 1023 K at a weight hourly space velocity of 3.6 × 10 -4 ml g -1 h -1 STP (Siew et al, 2015). Kinetic studies showed that glycerol decomposition and glycerol dehydrogenation as the most probably competing route in a parallel pathway for syngas production.…”

Advances in catalytic conversion of methane and carbon dioxide to highly valuable products

“…For example, Slagtern et al. evaluated Ni/Ln/Al 2 O 3 (Ln=rare earth mixture) catalysts at 800°C and 1 atm, showing that the catalyst with a rare earth content of 10.7 wt% Ln is more active and stable than the unpromoted catalyst . Promoting Al 2 O 3 by Mg can also improve Ni/Al 2 O 3 catalysts.…”