2% Ru/Al2O3 pellets

Koo, Kee Young, et al. 24th North American Catalysis Society Meeting. NAM, 2015.

In general chemical processes including natural gas steam reforming (NGSR) for H3 production, conventional packed bed reactors with ceramic pellet catalysts are used. It increases the reactor volume due to the problem that a large amount of pellet catalyst is required to obtain sufficient conversion. To overcome these problems, metal structured catalysts have been investigated as an alternative. Hence a proprietary coating method of highly dispersed Ru catalyst on a metal substrate was developed and the catalytic activity of the metal monolithic catalyst in NGSR was investigated in comparison with Ru/Al2O3 pellet catalyst.
After preliminary treatment of the metal surface by a proprietary method, it was calcined at 900℃ for 6 hours. The pre-calcined structured support was coated with 10wt% Al2O3 and then a proprietary coating method was applied to the highly dispersed Ru catalyst. For comparison, 2% Ru/Al2O3 pellet catalyst was used as a reference catalyst. The CH4 conversion of Ru/Al2O3 pellet catalyst and Ru/Al2O3 coated monolithic catalyst at different space velocities was investigated.

Porta, Alessandro, Carlo G. Visconti, and Luca Lietti. (2019)

CO2 is the most abundant greenhouse gas and its utilization as a carbon source is environmentally and industrially attractive. Ru-based catalysts are of interest for CO2 conversion due to their activity at lower temperatures, higher CO2 conversions and almost complete selectivity towards methane. To optimize process efficiency under industrially relevant conditions, the effect of catalytic Ru/Al2O3 pellet size on catalytic performance was investigated.
Uniformly impregnated Ru/Al2O3 pellets were obtained by impregnation solution. Ru/Al2O3 pellets were tested for CO2 methanation under industrial conditions. No differences in CO2 conversion and CH4 selectivity were observed between powdered uniformly impregnated pellets and powdered eggshell pellets, indicating that acid introduction did not affect the catalytic performance. Subsequently, the uniformly impregnated pellets were tested to evaluate the role of internal diffusion limitations.

Alessandro, Porta. (2020).

In order to reduce CO2 emissions and comply with international agreements, the use of renewable energy and carbon capture technologies is expected to increase significantly. The efficiency of the CO2 methanation process over Ru/Al2O3 pellets catalysts under optimized industrially relevant conditions was investigated. When using low Ru loadings (0.5 wt.%), it was found that eggshell catalysts can be obtained by impregnation on large Al2O3 particles due to the interaction between the Ru precursor and the support. In order to improve the catalyst activity, the effect of the Ru loading in the range of 0.5 - 5 wt.% was also investigated under kinetically controlled conditions. The preparation method used allowed to obtain highly dispersed systems with an average Ru particle size below 2.5 nm.
In order to study the effect of the catalyst support size, the recipe with the highest turnover per gram of catalyst (5 wt.% Ru/Al2O3 pellets) was replicated using supports of 800 and 2300 μm. In these cases, the conversion and selectivity of the process differed from the results obtained under kinetically controlled regime. Therefore, due to the slow diffusion of CO2 within the catalyst pore system and the slow heat dissipation at the gas-solid interface, the catalyst particle size increases and the methane yield decreases. The feasibility of the CO2 methanation process with Ru/Al2O3 pellets catalysts to achieve CO2 conversion rates exceeding 98% and complete CH4 selectivity has also been demonstrated.

Nawdali, Mostafa, and Daniel Bianchi. Applied Catalysis A: General 231.1-2 (2002): 45-54.

The effect of the Ru precursor of the Ru/Al2O3 pellet catalyst was investigated using CO as a probe molecule. The amount and reactivity of the adsorbed CO species formed on the reduced solid were investigated using mass and FTIR spectroscopy. The effect of the Ru precursor appears to be mainly due to the steps involved in the catalyst preparation (dispersion, site blocking, reconstruction), while there is no strong electronic interaction between the residual chlorine and the adsorbed CO species.
For the FTIR studies, the Ru/Al2O3 pellet catalyst was compressed into a disk (Φ = 1.8 cm, m = 40-90 mg) that was placed in the sample holder of a small internal volume stainless steel IR cell described elsewhere, allowing in situ treatment of the solid at atmospheric pressure (293-900 K) with a gas flow rate of 150-2000 cm/min. Another analytical system was used to measure the composition of the gas mixture at the outlet of the quartz microreactor (1 atm total pressure) using a quadrupole mass spectrometer to obtain the amount of CO adsorbed during the hydrogenation process and the CH4 production rate.