@article{GirodLohmannSchlueteretal.2020, author = {Girod, Kai and Lohmann, Heiko and Schl{\"u}ter, Stefan and Kaluza, Stefan}, title = {Methanol Synthesis with Steel-Mill Gases: Simulation and Practical Testing of Selected Gas Utilization Scenarios}, series = {Processes}, volume = {8}, journal = {Processes}, number = {12}, publisher = {MDPI}, doi = {10.3390/pr8121673}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-26928}, year = {2020}, language = {en} } @article{GirodBreitkreuzHenningetal.2019, author = {Girod, Kai and Breitkreuz, Klaas and Henning, Torsten and Lohmann, Heiko and Kaluza, Stefan and Schluter, Stefan}, title = {Steel Mills as Syngas Source for Methanol Synthesis: Simulation and Practical Performance Investigations}, series = {Chemical Engineering Transactions}, volume = {74}, journal = {Chemical Engineering Transactions}, publisher = {AIDIC}, isbn = {978-88-95608-71-6}, issn = {2283-9216}, doi = {10.3303/CET1974080}, pages = {475 -- 480}, year = {2019}, abstract = {In the present contribution, the utilization of steel-mill gases for an industrial methanol synthesis process is described. The focus of this work is on the influence of syngas compositions derived from steel-mill gases on an industrial Cu/ZnO/Al2O3 catalyst. Elevated CO2 and H2O concentrations seem to have an irreversible impact on the activity of the catalyst. In order to obtain realistic gas composition for the catalyst tests, a process simulation of the methanol synthesis was conducted. The calculated gas compositions at the reactor inlet were applied in a practical test in order to evaluate the catalyst stability under steel mill gas conditions. No noticeable deactivation was observed.}, language = {en} } @article{WiesmannYounSuhKaluzaetal.2020, author = {Wiesmann, Thomas and Youn Suh, Sung and Kaluza, Stefan and Lohmann, Heiko and Zeidler-Fandrich, Barbara}, title = {Catalytic Oxygen Removal from Synthetic Coke Oven Gas: A Comparison of Sulfided CoMo/γ-Al 2 O 3 and NiMo/γ-Al 2 O 3 Catalysts with Pt/γ-Al 2 O 3 as Benchmark Catalyst}, series = {Chemie Ingenieur Technik}, volume = {92}, journal = {Chemie Ingenieur Technik}, number = {10}, publisher = {Wiley}, doi = {10.1002/cite.202000067}, pages = {1533 -- 1541}, year = {2020}, language = {en} } @article{StrucksWatermannWeberetal.2021, author = {Strucks, Peter and Watermann, Clara and Weber, Konradin and Kaluza, Stefan}, title = {Systematic Investigations of Vibrational and Fluid-Mechanical Stability of Coated Monolithic Catalysts}, series = {Chemie Ingenieur Technik}, volume = {93}, journal = {Chemie Ingenieur Technik}, number = {5}, publisher = {Wiley}, issn = {1522-2640}, doi = {10.1002/cite.202000233}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-28930}, pages = {1 -- 6}, year = {2021}, abstract = {Heterogeneous catalysts usually consist of porous, inorganic materials. Especially in the mobile application, e.g., in exhaust gas catalysis as a part of the gas line of an engine, there are loads due to vibrations and high gas velocities. It can be assumed that physical stress will lead to a loss of the catalytically active coating. The present contribution describes experimental setups and methods for a systematic and reproducible investigation of the main influences to the mass loss due to vibrational and fluid-mechanical stress caused by particle-free gas flows.}, language = {en} } @article{FallingKaluzaStrucks2021, author = {Falling, Luisa and Kaluza, Stefan and Strucks, Peter}, title = {A Short Review on Ni-Catalyzed Methanation of CO²: Reaction Mechanism, Catalyst Deactivation, Dynamic Operation}, series = {Chemie Ingenieur Technik}, volume = {93}, journal = {Chemie Ingenieur Technik}, publisher = {Wiley}, issn = {1522-2640}, doi = {10.1002/cite.202100049}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-32134}, pages = {1526 -- 1536}, year = {2021}, abstract = {Today, the use of renewable energies and recycling of climate-changing gases are increasingly important. In this context,coupling of methanation with small, decentralized CO2sources such as biogas plants provides one possibility. However,fluctuating availability of renewables for hydrogen production in combination with small storage volumes result in anenhanced demand for dynamic process operation. This leads to new research challenges with respect to the required cata-lysts and the overall process design. To draw reliable conclusions about the catalytic performance under dynamic processoperation, the mechanism of the methanation reaction as well as typical deactivation procedures of the catalyst appliedunder steady-state conditions have to be reviewed thoroughly.}, language = {en} } @article{GirodLohmannKaluza2021, author = {Girod, Kai and Lohmann, Heiko and Kaluza, Stefan}, title = {Methanol Synthesis with Steel Mill Gases: Performance Investigations in an On-Site Technical Center}, series = {Chemie Ingenieur Technik}, volume = {93}, journal = {Chemie Ingenieur Technik}, number = {5}, publisher = {Wiley}, organization = {Wiley}, issn = {1522-2640}, doi = {10.1002/cite.202000230}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-34409}, pages = {850 -- 855}, year = {2021}, language = {en} } @article{FailingKaluzaStrucks2023, author = {Failing, Luisa and Kaluza, Stefan and Strucks, Peter}, title = {Catalytic CO2 methanation: Providing optimal test conditions for kinetic investigations}, series = {Chemie Ingenieur Technik}, volume = {95}, journal = {Chemie Ingenieur Technik}, number = {5}, publisher = {Wiley}, issn = {1522-2640}, doi = {10.1002/cite.202200201}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-40026}, pages = {749 -- 753}, year = {2023}, abstract = {In the context of using renewable energies and recycling climate-changing gases, methanation of CO2 provides one possibility. However, volatile availability of renewable energies for hydrogen production and fluctuating CO2streams from different sources lead to enhanced demand in investigating the influence of dynamic process operation on the catalyst performance, including detailed kinetic characterization. Reliable kinetic measurements require isothermal temperature control and absence of macrokinetic diffusion limitations. Both were investigated in this work while the determination of steady-state kinetic parameters is part of ongoing studies. Furthermore, a detailed analysis with respect to the long-term-stability of the nickel-based catalyst was performed}, language = {en} } @article{WinterDiehlTelaaretal.2024, author = {Winter, Franziska Luise and Diehl, Patrick and Telaar, Pascal and Watermann, Clara Maria and Kaluza, Stefan and Muhler, Martin and Apfel, Ulf-Peter and Zeidler-Fandrich, Barbara}, title = {Influence of the catalyst precursor for cobalt on activated carbon applied in ammonia decomposition}, series = {Catalysis Today}, volume = {429}, journal = {Catalysis Today}, publisher = {Elsevier}, issn = {0920-5861}, doi = {10.1016/j.cattod.2023.114502}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-46600}, pages = {9}, year = {2024}, abstract = {Ammonia is a key compound for storing and transporting green hydrogen. However, the efficient release of stored hydrogen through thermocatalytic ammonia decomposition is achievable only at temperatures around 600 °C, particularly with non-noble metal-based catalysts, which prove to be both ecologically and economically more feasible. In this study, electrically conductive activated carbon was selected as the catalyst support, chosen specifically for its suitability in achieving more energy-efficient direct reactor heating through the ohmic resistance of the catalysts. Cobalt salts were wet impregnated on activated carbon investigating the influence of different precursors (cobalt nitrate and cobalt acetate) and pyrolysis temperatures (400 °C and 600 °C) under N2 flow on the cobalt particle size and the incorporation of cobalt into the carbon matrix. TEM imaging and CO-chemisorption revealed well dispersed cobalt particles with sizes below 10 nm for the catalysts synthesized from the cobalt nitrate precursor. On the other hand, cobalt acetate led to about nine times larger Co agglomerates, which were partially detached from the carbon matrix. Moreover, this substantial difference in the Co particle size results in a significantly higher ammonia conversion for cobalt nitrate-based catalysts, achieving 94 \% of ammonia conversion at 600 °C. Furthermore, the long-term stability test of the cobalt nitrate-based catalyst resulted in a slight deactivation of only 2 \% ammonia conversion at 500 °C.}, subject = {Katalyse}, language = {en} } @inproceedings{WachtKaluzaFleiger2023, author = {Wacht, Anika and Kaluza, Stefan and Fleiger, Philipp}, title = {Carbon Capture and Utilization in Cement Industry—Aspects of the Production of E-Fuels by Upcycling Carbon Dioxide}, series = {Smart, Sustainable Manufacturing in an Ever-Changing World: Proceedings of International Conference on Competitive Manufacturing (COMA '22)}, booktitle = {Smart, Sustainable Manufacturing in an Ever-Changing World: Proceedings of International Conference on Competitive Manufacturing (COMA '22)}, editor = {Leipzig, Konrad von and Sacks, Natasha and Mc Clelland, Michelle}, publisher = {Springer Nature}, address = {Cham}, isbn = {9783031156014}, issn = {2194-0525}, doi = {10.1007/978-3-031-15602-1_44}, pages = {603 -- 612}, year = {2023}, subject = {Carbon dioxide capture and utilization}, language = {en} } @article{GreuelWatermannLohmannetal.2025, author = {Greuel, Marc and Watermann, Clara Maria and Lohmann, Heiko and Kaluza, Stefan and Apfel, Ulf-Peter and Zeidler-Fandrich, Barbara}, title = {The conversion of ethanol over 3d-metal saponite-like smectites}, series = {Materials Advances}, journal = {Materials Advances}, number = {6}, publisher = {Royal Society of Chemistry}, issn = {2633-5409}, doi = {10.1039/d4ma01036a}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-52973}, pages = {2885 -- 2898}, year = {2025}, abstract = {The replacement of fossil fuel processes with renewable pathways is critical to circumvent climate change and environmental risks. A process of interest is the production of 1,3-butadiene (BD), which is primarily derived as a by-product of naphtha steam cracking. A sustainable alternative path involves converting renewable ethanol to BD via the Lebedev process, which requires a catalyst with balanced redox, acidic, and basic sites. Due to the necessity of a multifunctional catalyst, existing materials for this reaction are either comprised of catalyst mixtures or supported catalysts. In this study, we introduce a bulk material, saponite, containing M-O-Si sites, which combine required catalytic sites for the ethanol to BD (ETB) reaction in one material. The product composition in ethanol conversion were strongly dependent on the type of 3d-metal used, while no conclusive correlation between surface properties, conversion, and product composition was observed. Herein, using V-Sap*, we achieved an ethene productivity of 448 gethene kgcat-1 h-1 (74\%) at 573.15 K. High acetaldehyde productivity was maintained with Cu-Sap* (466 gAcA kgcat-1 h-1, 49\%) at 573.15 K and Zn-Sap (528 gAcA kgcat-1 h-1, 55\%) at 723.15 K. Mg-Sap primarily produced ethene but also yielded 10 gBD kgcat-1 h-1 BD at 723.15 K. Higher BD outputs were observed with Ni-Sap (31 gBD kgcat-1 h-1 at 523.15 K) and Mn-Sap* (51 gBD kgcat-1 h-1 at 723.15 K). This underscores the potential of saponite-based materials for flexible product outputs in ethanol conversion, influenced by the choice of integrated 3d-metal.}, subject = {Butadien}, language = {en} } @techreport{FailingKaluzaStrucks2024, author = {Failing, Luisa and Kaluza, Stefan and Strucks, Peter}, title = {Power2Gas - Katalytische Methanisierung von CO₂ als Baustein einer erfolgreichen Energie- und Rohstoffwende}, address = {D{\"u}sseldorf}, organization = {Hochschule D{\"u}sseldorf}, issn = {2625-3690}, doi = {10.20385/opus4-4514}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-45143}, pages = {27}, year = {2024}, abstract = {Die katalytische Methanisierung von Kohlendioxid (CO2) mit Hilfe von elektrolytisch erzeugtem Wasserstoff (H2) aus erneuerbaren Energiequellen kann einen wichtigen Beitrag zur Reduktion von CO2-Emissionen leisten. Aufgrund einer immer st{\"a}rker fluktuierenden Energie- und Rohstoffbereitstellung spielt die M{\"o}glichkeit einer flexiblen, dynamischen Betriebsweise eine zunehmend große Rolle f{\"u}r zuk{\"u}nftige Technologien. Dies bedingt auch im Fall der katalytischen Methanisierung umfangreiche Untersuchungen, um zu ermitteln, inwieweit eine dynamische Fahrweise Auswirkungen auf Prozess und Katalysator besitzt. An diesem Punkt setzte das HiFF-Projekt Power2Gas an. So wurden verschiedene nickelbasierte Katalysatorsysteme synthetisiert, wobei sich der via Impr{\"a}gnierung hergestellte Ni/Al2O3-Katalysator sowohl aufgrund seiner guten Leistung als auch der praktikablen und reproduzierbaren Herstellung als geeignetes Benchmark-System f{\"u}r weitere Untersuchungen - vor allem im kinetischen Bereich - erwies. W{\"a}hrend umfassender Parametervariationen wurden kinetische Datens{\"a}tze im station{\"a}ren Zustand bestimmt, die zur Modellierung der katalysierten CO2-Methanisierung verwendet werden k{\"o}nnen. Dar{\"u}ber hinaus wurden in ausgew{\"a}hlten Versuchsreihen die isotherme Temperaturkontrolle und eine ausreichende Langzeitstabilit{\"a}t sichergestellt sowie makrokinetische Diffusionsbeschr{\"a}nkungen ausgeschlossen. Die Ergebnisse wurden in einer peer-review-Publikation ver{\"o}ffentlicht und auf zwei Konferenzen pr{\"a}sentiert. Sie waren zudem die Basis f{\"u}r eine erfolgreiche Masterarbeit und flossen in die Antragstellung im Rahmen des DFG-Programms „Großger{\"a}teaktion f{\"u}r Hochschulen f{\"u}r Angewandte Wissenschaften" ein.}, language = {de} }