Insights on a Methanation Catalyst Aging Process: Aging Characterization and Kinetic Study

Abstract

Power to gas systems is one of the most interesting long-term energy storage solutions. As a result of the high exothermicity of the CO2 methanation reaction, the catalyst in the methanation subsystem is subjected to thermal stress. Therefore, the performance of a commercial Ni/Al2O3 catalyst was investigated over a series of 100 hour-long tests and in-process relevant conditions, i.e. 5 bar from 270 to 500 °C. Different characterization techniques were employed to determine the mechanism of the observed performance loss (N2 physisorption, XRD, TPO). The TPO analysis excluded carbon deposition as a possible cause of catalyst aging. The BET analysis evidenced a severe reduction in the total surface area for the catalyst samples tested at higher temperatures. Furthermore, a direct correlation was found between the catalyst activity decline and the drop of the catalyst specific surface. In order to correctly design a reliable methanation reactor, it is essential to have a kinetic model that includes also the aging kinetics. For this purpose, the second set of experiments was carried out, in order to determine the intrinsic kinetics of the catalyst. The kinetic parameters were identified by using nonlinear regression analysis. Finally, a power-law aging model was proposed to consider the performance loss in time.

CO2valorisation towards alcohols by Cu-based electrocatalysts: challenges and perspectives

“…This kind of technology is well known for producing synthetic fuels and can be easily scaled-up at an industrial level. [21][22][23][24] In this process, hydrogen reacts with CO 2 via hydrogenation reaction to generate methanol and water at high reaction temperatures and pressures (≥ 220 o C and ≥ 2 MPa H 2 ), due to low kinetics under milder conditions. To be sustainable and independent from fossil fuels, the H 2 can be produced by water electrolysis with renewable energy.…”

Understanding structure-activity relationships in highly active La promoted Ni catalysts for CO2 methanation

“…The reaction mechanism is elucidated using in situ DRIFTs whilst feeding a reaction mixture (CO2/H2/N2 = 1/4/1) at low oven temperatures. The stability of the La catalyst is investigated under transient conditions (shut-down and start-up), important for the Power to Gas technology [51], but to the best of our knowledge, is scarcely reported [52,53].…”

Physico-Chemical Modifications Affecting the Activity and Stability of Cu-Based Hybrid Catalysts during the Direct Hydrogenation of Carbon Dioxide into Dimethyl-Ether

“…Nowadays, the increase in global warming is a crucial issue which has to be coped with. The development of catalysts and processes for producing synthetic fuels as an alternative to traditional fossil resources has indeed recently received particular attention in the power-to-fuels research field [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Among several technologies, power-to-fuel seems to be one of the most promising to produce a range of synthetic fuels and chemicals (e.g., methane, methanol, dimethyl-ether, light and heavy hydrocarbons, etc.)…”