Langzeitstabile, Co-basierte Katalysatoren für die mit Lastwechseln betriebene Sabatierreaktion

• Antragsteller: Professor Dr. Marcus Bäumer; Professor Dr.-Ing. Lutz Mädler; Professor Dr.-Ing. Jorg Thöming
• Fachliche Zuordnung: Chemische und Thermische Verfahrenstechnik ; Mechanische Verfahrenstechnik ; Physikalische Chemie von Molekülen, Flüssigkeiten und Grenzflächen, Biophysikalische Chemie ; Technische Chemie
• Förderung: Förderung von 2018 bis 2023
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 406935056

• Erstellungsjahr: 2022

Zusammenfassung der Projektergebnisse

The methanation of carbon oxides with hydrogen is a promising approach for the chemical storage of fluctuating renewable energies. For this, “green” hydrogen can be electrochemically produced using excess solar or wind energy. Sequestered carbon oxides from industrial exhaust sources, e.g. from combustion or steel/cement production, can be employed leading to a reduction of emissions. The fluctuating nature of the feed for methanation requires an understanding of methanation reaction under dynamic conditions, i.e. by considering changing volume flows and feed compositions of CO2, CO and H2. Dynamically changing reaction conditions may lead to catalyst deactivation caused for example by poisoning of the active material or by formation of hot spots. Therefore, a holistic approach is required that combines novel material synthesis techniques, catalytic testing under the challenging conditions of dynamic operation, and an analysis of the methanation process with state-of-the-art operando technology, which should be feasible using an industrial-scale reactor tube diameter. During the SPP project we gained significant insight into the dynamic methanation of carbon oxides. Double Flame Spray Pyrolysis was employed to synthetize highly defined Co-Al2O3 model catalysts. We studied the effects of promoters Zr, Sm und Pt on isostructural catalysts for methanation of CO and CO2. Promoter effects were isolated and compared for the two educts. The dynamic sorption of reactants was studied using Periodic Transient Kinetics (PTK) technique to understand dynamic operation of CO2 methanation of cobalt catalysts supported on TiO2, SiO2 and mixed TiO2-SiO2. We found that adsorption of water on TiO2 leads to sorption enhanced methanation during dynamic operation. Even though some deactivation was observed, the reaction mechanism remained unchanged before and after aging under methanation conditions. By co-feeding CO2 and CO during methanation over platinum promoted Co/Al2O3 catalysts prepared by DFSP we found that the presence of CO2 has a promoting effect on CO methanation. The effect could be explained on the basis of a blocking of basic surface sites on the oxide component by adsorption of CO2 and carbonate formation. Furthermore, for the very first time, we showed that operando NMR studies of a gas phase reaction are possible in a monolithic catalyst even at elevated temperatures as required for the Sabatier reaction. We successfully demonstrated also for changing loads that flow rate, concentration and temperature information can be obtained operando in all spatial directions within an opaque catalytic reactor. Accompanied by state-of-the-art 3D CFD simulations, we further investigated and highlighted temperature control through foam catalyst carriers, that ensure both, long-term stable operation of small-scale methanation plants and secure process operation of further operando studies in NMR machines. Our research paves the way to more catalytic in-depth operando NMR studies with potential goal of characterizing multi-phase reactions, such as the Fischer-Tropsch synthesis, as well.

Projektbezogene Publikationen (Auswahl)

• Coupled conjugate heat transfer and heat production in open-cell ceramic foams investigated using CFD. International Journal of Heat and Mass Transfer, 139(c(2019, 8)), 600-612.
  Sinn, Christoph; Pesch, Georg R.; Thöming, Jorg & Kiewidt, Lars
  
• CFD Simulations of Radiative Heat Transport in Open-Cell Foam Catalytic Reactors. Catalysts, 10(6), 716.
  Sinn, Christoph; Kranz, Felix; Wentrup, Jonas; Thöming, Jorg; Wehinger, Gregor D. & Pesch, Georg R.
  
• Influence of Pressure, Velocity and Fluid Material on Heat Transport in Structured Open-Cell Foam Reactors Investigated Using CFD Simulations. ChemEngineering, 4(4), 61.
  Sinn, Christoph; Wentrup, Jonas; Thöming, Jorg & Pesch, Georg R.
  
• A large fixed bed reactor for MRI operando experiments at elevated temperature and pressure. Review of Scientific Instruments, 92(4).
  Ridder, Harm; Sinn, Christoph; Pesch, Georg R.; Ilsemann, Jan; Dreher, Wolfgang & Thöming, Jorg
  
• Comparing Co‐catalytic Effects of ZrOx, SmOx, and Pt on COx Methanation over Co‐based Catalysts Prepared by Double Flame Spray Pyrolysis. ChemCatChem, 13(12), 2815-2831.
  Stahl, Jakob; Ilsemann, Jan; Pokhrel, Suman; Schowalter, Marco; Tessarek, Christian; Rosenauer, Andreas; Eickhoff, Martin; Bäumer, Marcus & Mädler, Lutz
  
• Heat Transport in Open-Cell Foams: CFD Analysis of Artificial Heat Sources vs Fully Resolved Exothermal Reactions. Industrial & Engineering Chemistry Research, 60(12), 4542-4551.
  Sinn, Christoph; Wentrup, Jonas; Pesch, Georg R. & Thöming, Jorg
  
• Structure-heat transport analysis of periodic open-cell foams to be used as catalyst carriers. Chemical Engineering Research and Design, 166(c(2021, 2)), 209-219.
  Sinn, Christoph; Wentrup, Jonas; Pesch, Georg R.; Thöming, Jorg & Kiewidt, Lars
  
• Spatially resolved direct gas-phase thermometry in chemical reactors using NMR. Chemical Engineering Journal, 433(c(2022, 4)), 133583.
  Ridder, Harm; Sinn, Christoph; Pesch, Georg R.; Dreher, Wolfgang & Thöming, Jorg
  
• The Impact of Support Material of Cobalt‐Based Catalysts Prepared by Double Flame Spray Pyrolysis on CO2 Methanation Dynamics. ChemCatChem, 14(16).
  Gäßler, Max; Stahl, Jakob; Schowalter, Marco; Pokhrel, Suman; Rosenauer, Andreas; Mädler, Lutz & Güttel, Robert