Development of a Structured Reactor System for CO₂ Methanation under Dynamic Operating Conditions

Abstract

Herein, the use of an additively manufactured rack‐type reactor for CO2 methanation under dynamic operating conditions is proposed. In detail, CO2 methanation using an additively manufactured structured reactor (catalyst: 2.5 wt% Ru/Al2O3/MgO) is reported. The dynamic operation is simulated by changing the reactant flow rates (loads) based on the operation strategy of an electrolyzer connected to a wind farm. Due to the high heat conductivity of the metallic structures, temperature hotspots related to load variations are avoided efficiently. In the test rig, these structured reaction systems reach equilibrium CO2‐conversions with only minor axial temperature gradients for various loads and thus offer a high potential for the dynamic operation of exothermic gas‐phase processes.

Hydrogenation of CO/CO2 mixtures under unsteady-state conditions: Effect of the carbon oxides on the dynamic methanation process

“…Several experimental studies towards the effect of concentration forcing on the dynamic reactor response for methanation have already been performed at the micro and macro scale (Yadav and Rinker, 1990;Adesina et al, 1995;Klusáček and Stuchlý, 1995;Kreitz et al, 2019a). At the macro scale Stiegler et al (Stiegler et al, 2019) and Theurich et al (Theurich et al, 2020) recently demonstrated experimentally that improved temperature control of an unsteady-state methanation reactor is possible in structured reactors system (Stiegler et al, 2019) or by product recirculation (Theurich et al, 2020). With focus at the micro scale one of the first studies was performed by Van Ho and Harriott (Van Ho, 1980) reporting that the CH 4 response differs for CO 2 and CO methanation.…”

Transient Flow Rate Ramps for Methanation of Carbon Dioxide in an Adiabatic Fixed‐Bed Recycle Reactor

“…With the aim to reduce the costs of the hydrogen storage by minimizing upstream storage capacities (up to 8% of the total investment costs can be saved), the unsteady‐state operation of the exothermic methanation reaction is demanded. However, the occurring phenomena and operation strategies under dynamic conditions are not exhaustively addressed in scientific literature thus far, but receive more attention in recent years . One promising approach is adiabatically operated fixed‐bed reactors, which show a good partial and excess load behavior, since the chemical equilibrium is reached within the residence time.…”

Review of CO2 Reduction on Supported Metals (Alloys) and Single-Atom Catalysts (SACs) for the Use of Green Hydrogen in Power-to-Gas Concepts

“…These effects lead individually or together to the loss of active Ru surface area during CO/CO 2 methanation with time on stream. More importantly, it was demonstrated that supported Ru catalysts (Ru/Al 2 O 3 ) are also better catalysts than the corresponding Ni-based catalyst (Ni/Al 2 O 3 ) under dynamic operation conditions involving the variation of reactor load [78,79]. This property is one of the prerequisites for the future decentralized use of CO 2 methanation reactors/stations.…”