@misc{GuentherMaussKlaueretal., author = {G{\"u}nther, Vivien and Mauß, Fabian and Klauer, Christian and Schlawitschek, Christiane}, title = {Kinetic Monte Carlo simulation of the epitaxial growth of Si(100)}, series = {Physica status solidi : C}, volume = {9}, journal = {Physica status solidi : C}, number = {10-11}, issn = {1610-1634}, pages = {1955 -- 1962}, language = {en} } @misc{GuentherMauss, author = {G{\"u}nther, Vivien and Mauß, Fabian}, title = {Si(100)2×1 Epitaxy: A Kinetic Monte Carlo Simulation of the Surface Growth}, series = {Physics Procedia}, journal = {Physics Procedia}, number = {40}, issn = {1875-3892}, pages = {56 -- 64}, language = {en} } @misc{AslanjanKlauerPerlmanetal., author = {Aslanjan, Jana and Klauer, Christian and Perlman, Cathleen and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Simulation of a Three-Way Catalyst Using Transient Single and Multi-Channel Models}, series = {SAE technical paper}, journal = {SAE technical paper}, number = {2017-01-0966}, issn = {0148-7191}, doi = {10.4271/2017-01-0966}, pages = {11 Seiten}, language = {en} } @misc{MuellerRachowGuentheretal., author = {M{\"u}ller, Klaus and Rachow, Fabian and G{\"u}nther, Vivien and Schmeißer, Dieter}, title = {Methanation of Coke Oven Gas with Nickel-based catalysts}, series = {International Journal of Environmental Science}, journal = {International Journal of Environmental Science}, number = {4}, issn = {2367-8941}, pages = {73 -- 79}, abstract = {For a complete transition from fossil to CO₂ neutral energy supply new energy storage concepts are needed that allow energy supply in times of absence of regenerative power production as during dark doldrums. A promising renewable energy storage approach is the power to gas (to power) technique based on the production of synthetic natural gas (also called e-methane) by methanation of CO₂ with H₂. The latter is usually produced by electrolysis. In any power to gas concept, electrolysis is a very critical part, due to its high costs, stability issues, or limited power of required electrolysers. As an alternative source of hydrogen, we investigate the methanation of coke oven gas (COG). COG is a byproduct of the carbon rich coke production from coal for the steel industry, with a high amount of hydrogen (~60vol\%). Coke oven gas furthermore contains CH₄(~25vol\%), CO (5-8vol\%), and CO₂(1-3vol\%), making it an attractive feedstock for the production of synthetic energy carriers like methane. In the present study, the authors investigate the direct conversion of CO and CO₂ from COG into e-methane. Compared to stoichiometric conversion, the COG hydrogen content is too high for catalytic methanation of CO₂. In order to achieve a higher methane yield, the addition of CO₂ from air, flue gas, or coal gasification can compensate the surplus of hydrogen in the coke oven gas. The process is evaluated by the conversion of CO and CO₂, the catalyst selectivity towards higher hydrocarbons for varying temperatures, and the CH₄ yield.}, language = {en} } @misc{RakhiGuentherRichteretal., author = {Rakhi, Rakhi and G{\"u}nther, Vivien and Richter, Jana and Mauß, Fabian}, title = {Steam reforming of methane over nickel catalyst using a one-dimensional model}, series = {International Journal of Environmental Sciences}, volume = {5}, journal = {International Journal of Environmental Sciences}, number = {1}, issn = {2519-5549}, doi = {10.47604/ijes.1520}, pages = {1 -- 32}, abstract = {Steam reforming of hydrocarbons is a well established chemical process which provides synthesis gas (H2 and CO). These synthesis products can hence be converted to numerous valuable basic chemicals. For the industrial application of steam reforming, a detailed understanding of the process is a prerequisite. Models that capture the detailed homogeneous and heterogeneous reaction kinetics and the comprehensive transport processes as well as their interaction have the potential to optimize the catalytic process without expensive experimental campaigns. In this paper, a detailed investigation has been done using a multi-step reaction mechanism for modeling steam reforming of methane over nickel-based catalyst using a one-dimensional (1D) model, LOGEcat [1]. The model is applicable to the simulation of all standard after-treatment catalytic processes of combustion exhaust gas along with other chemical processes involving heterogeneous catalysis, such as, the Sabatier process [27]. It is a 1D tool, thus is computationally cost effective and is based on a series of perfectly stirred reactors (PSR). The model is used to perform the simulations for various reactor conditions in terms of temperature, pressure, flow rates and steam-to-carbon (S/C) ratio. Several chemical reaction terms, such as, selectivity, yield, conversion, and mole fraction have been shown with respect to the varied parameters and the results are compared with 2D simulations and experimental reference data. We report a very good agreement of the various profiles produced with 1D model as compared to the reference data. Note that the main aim of this study is to check how far the 1D model can capture the basic chemistry for modeling steam reforming of methane over nickel-based catalysts. It is interesting to note that the cost effective reduced order model is capable to capture the physics and chemistry involved with a multi-step reaction mechanism showing the predictive capability of the model. This study forms the basis for further analysis towards the thermochemistry of the species to develop a kinetically consistent reaction mechanism.}, language = {en} } @misc{RakhiGuentherMauss, author = {Rakhi, Rakhi and G{\"u}nther, Vivien and Mauß, Fabian}, title = {A detailed surface reaction mechanism to investigate oxidation of methane over nickel catalyst}, series = {Proceedings in Applied Mathematics \& Mechanics : PAMM}, volume = {22}, journal = {Proceedings in Applied Mathematics \& Mechanics : PAMM}, number = {1}, issn = {1617-7061}, doi = {10.1002/pamm.202200055}, abstract = {We have developed a kinetically consistent detailed surface reaction mechanism for modeling the oxidation of methane over a nickel-based catalyst. A one-dimensional model, LOGEcat based on the single-channel 1D catalyst model, is used to perform the simulations. The original multi-step reaction mechanism is thermodynamically consistent and consists of 52 reactions. By thermodynamic consistency, we mean that the equilibrium is achieved with the support of the Arrhenius parameters and does not depend on the thermochemistry of the species involved in the considered reactions. The detailed mechanism developed in this investigation contains 26 reversible reactions. These reactions are obtained with the use of the thermochemistry of the species. The study focuses on ensuring kinetic consistency and this is done with the help of thermodynamic analysis by bringing the thermochemistry of the species in play in order to develop a surface reaction mechanism. The new mechanism can be used to understand the other processes, for example, steam- and dry-reforming of methane over nickel, however, the main focus of the paper is to check the performance of the detailed mechanism for catalytic partial oxidation of methane. The applicability of the mechanism is checked for various reactor conditions in terms of parameters such as temperature and pressure by comparing the results with the available reference data. The detailed mechanism developed in this study is able to accurately express oxidation of methane over the nickel catalyst for the considered reactor conditions.}, language = {en} } @misc{RakhiGuentherMauss, author = {Rakhi, Rakhi and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Insights into dry reforming of methane over nickel catalyst using a thermodynamic model}, series = {Reaction Kinetics, Mechanisms and Catalysis}, journal = {Reaction Kinetics, Mechanisms and Catalysis}, issn = {1878-5204}, doi = {10.1007/s11144-023-02426-8}, pages = {14}, abstract = {A thermodynamic model is developed using a one-dimensional model, LOGEcat to understand the dry reforming of methane over nickel-based catalysts. To do so, we have extended our previously developed mechanism (Rakhi and Shrestha in React Kinet, Mech Catal 135:3059-3083, 2022) which contains 21 reversible reactions by adding 5 more reversible reactions and updating the thermochemistry of one intermediate species. The adjusted mechanism contains 26 reversible reactions obtained with the help of thermodynamic analysis. This study focuses on using the thermodynamic model for dry reforming of methane and insights into the reaction pathways and sensitivity analysis for the kinetically consistent surface reaction mechanism. The applicability of the mechanism is examined for reactor conditions in terms of parameters such as temperature by comparing the results with the available reference data. The mechanism is able to accurately express the reforming conditions of methane over the nickel catalyst for complete range of temperature and also provide useful insights into the reaction pathways established with the thermodynamic model.}, language = {en} } @misc{RichterRachowIsraeletal., author = {Richter, Jana and Rachow, Fabian and Israel, Johannes and Roth, Norbert and Charlafti, Evgenia and G{\"u}nther, Vivien and Flege, Jan Ingo and Mauß, Fabian}, title = {Reaction Mechanism Development for Methane Steam Reforming on a Ni/Al2O3 Catalyst}, series = {Catalysts}, volume = {13}, journal = {Catalysts}, number = {5}, issn = {2073-4344}, doi = {10.3390/catal13050884}, pages = {23}, abstract = {In this work, a reliable kinetic reaction mechanism was revised to accurately reproduce the detailed reaction paths of steam reforming of methane over a Ni/Al2O3 catalyst. A steady-state fixed-bed reactor experiment and a 1D reactor catalyst model were utilized for this task. The distinctive feature of this experiment is the possibility to measure the axially resolved temperature profile of the catalyst bed, which makes the reaction kinetics inside the reactor visible. This allows for understanding the actual influence of the reaction kinetics on the system; while pure gas concentration measurements at the catalytic reactor outlet show near-equilibrium conditions, the inhere presented temperature profile shows that it is insufficient to base a reaction mechanism development on close equilibrium data. The new experimental data allow for achieving much higher quality in the modeling efforts. Additionally, by carefully controlling the available active surface via dilution in the experiment, it was possible to slow down the catalyst conversion rate, which helped during the adjustment of the reaction kinetics. To assess the accuracy of the revised mechanism, a monolith experiment from the literature was simulated. The results show that the fitted reaction mechanism was able to accurately predict the experimental outcomes for various inlet mass flows, temperatures, and steam-to-carbon ratios.}, language = {en} } @misc{RakhiShresthaGuentheretal., author = {Rakhi, Rakhi and Shrestha, Krishna Prasad and G{\"u}nther, Vivien and Mauß, Fabian}, title = {Kinetically consistent detailed surface reaction mechanism for steam reforming of methane over nickel catalyst}, series = {Reaction Kinetics, Mechanisms and Catalysis}, volume = {135}, journal = {Reaction Kinetics, Mechanisms and Catalysis}, number = {6}, issn = {1878-5204}, doi = {10.1007/s11144-022-02314-7}, pages = {3059 -- 3083}, language = {en} } @misc{VermaGuentherCharlaftietal., author = {Verma, Rakhi and G{\"u}nther, Vivien and Charlafti, Evgenia and Rachow, Fabian and Giri, Binod Raj and Hemaizia, Abdelkader and Th{\´e}venin, Dominique and Flege, Jan Ingo and Mauss, Fabian}, title = {Development of detailed surface reaction mechanism for methanation process based on experiments}, series = {Proceedings in applied mathematics and mechanics : PAMM}, volume = {26}, journal = {Proceedings in applied mathematics and mechanics : PAMM}, number = {1}, publisher = {Wiley}, address = {Weinheim}, issn = {1617-7061}, doi = {10.1002/pamm.70061}, pages = {1 -- 6}, abstract = {The pressure to reduce greenhouse gas emissions is growing, which demands new and innovative technologies to produce mobile as well as stationary energy. The methanation offers a pathway to reduce greenhouse gas emissions by directly converting to . This also plays a crucial role in "power-to-gas" (P2G) technologies by providing an approach to store excess renewable energy in the form of methane in an existing natural gas infrastructure. However, methanation is a complex process due to its exothermic nature, interaction of the gas species with the catalyst, and possible catalyst degradation. Therefore, a deeper understanding is required for the methanation reaction, its different reaction pathways, and side reactions. In this work, we aim to understand the direct production of synthetic natural gas from and in a Sabatier process with the help of experiments over a Ni/ catalyst. A detailed surface reaction mechanism is developed to extend the study numerically by validating the simulation results with the experimental data. A one-dimensional model, LOGEcat, based on a single-channel catalyst model, is used for kinetic modeling. Experiments as well as simulations have been performed at various conditions, such as temperature variation and dilution to the inlet composition. We have successfully captured the experimental trends using the kinetic model developed for the conditions considered for the analysis.}, language = {en} } @misc{VermaGuentherGirietal., author = {Verma, Rakhi and G{\"u}nther, Vivien and Giri, Binod Raj and Hemaizia, Abdelkader and Th{\´e}venin, Dominique and Mauss, Fabian}, title = {Kinetic modeling of CO₂ methanation for methane production : a comprehensive study}, series = {IFAC-PapersOnLine}, volume = {59}, journal = {IFAC-PapersOnLine}, number = {29}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {2405-8963}, doi = {10.1016/j.ifacol.2025.12.175}, pages = {18 -- 23}, abstract = {To understand the complex methanation reaction, experiments have been conducted at various operating conditions, for instance, temperature, inlet gas dilution, and inlet composition. In addition, a detailed surface reaction mechanism is developed to conduct the study numerically by validating the simulation results with the experimental data. The kinetic model developed in this study is able to capture the experimental trends successfully for all conditions considered for the analysis.}, language = {en} } @misc{VermaGuentherGirietal., author = {Verma, Rakhi and G{\"u}nther, Vivien and Giri, Binod Raj and Mauss, Fabian}, title = {Effect of pressure and nitrogen dilution on surface species and reaction kinetics in CO₂ methanation over Ni catalyst}, series = {IFAC-PapersOnLine}, volume = {59}, journal = {IFAC-PapersOnLine}, number = {29}, publisher = {Elsevier BV}, address = {Amsterdam}, issn = {2405-8963}, doi = {10.1016/j.ifacol.2025.12.172}, pages = {1 -- 5}, abstract = {The CO2 methanation process is studied under varying pressures to support the development of efficient and sustainable technologies aligned with emission reduction and hydrogen economy goals. Experiments at two pressures, followed by pressure-dependent simulations, show strong agreement. Additionally, surface species coverage is analyzed, offering insights into catalytic behavior. These findings aid in optimizing methanation by deepening understanding of reaction mechanisms and guiding the design of improved catalysts.}, language = {en} }