TY - GEN A1 - Abang, Roger Atini A1 - Lisk, Alexander A1 - Krautz, Hans Joachim T1 - Fireside corrosion of superheater materials under oxy-coal firing conditions T2 - Energy Procedia N2 - The present study investigates the fireside corrosion behavior of selected superheater materials, namely: T24, P92, VM12-SHC, A800HT, and 7RE10 under oxy-coal combustion atmospheres. Data on mass change, scale thickness, metal loss, surface morphology and micro-structural characteristics of corrosion products were obtained. The alloy specimens were analyzed by SEM-EDX, light microscopy and X-Ray diffraction techniques. The results after 2000 hours of exposure at a metal surface temperature of 600 °C indicate that metal wastage increased with decreasing Cr-content under oxy-coal conditions. Y1 - 2013 U6 - https://doi.org/10.1016/j.egypro.2013.08.035 SN - 1876-6102 VL - 40 SP - 304 EP - 311 ER - TY - GEN A1 - Findeisen, Alexander A1 - Klatt, Matthias A1 - Krautz, Hans Joachim T1 - Examination of the corrosion behaviour of selected power plant materials under various operating conditions KW - Korrosion KW - CCS Y1 - 2010 U6 - https://doi.org/http://dx.doi.org/10.1016/j.chemer.2010.05.006 ER - TY - GEN A1 - Akay, Ömer A1 - Bashkatov, Aleksandr A1 - Coy, Emerson A1 - Eckert, Kerstin A1 - Einarsrud, Kristian Etienne A1 - Friedrich, Andreas A1 - Kimmel, Benjamin A1 - Loos, Stefan A1 - Mutschke, Gerd A1 - Röntzsch, Lars A1 - Symes, Mark D. A1 - Yang, Xuegeng A1 - Brinkert, Katharina T1 - Electrolysis in reduced gravitational environments: current research perspectives and future applications T2 - npj Microgravity N2 - Electrochemical energy conversion technologies play a crucial role in space missions, for example, in the Environmental Control and Life Support System (ECLSS) on the International Space Station (ISS). They are also vitally important for future long-term space travel for oxygen, fuel and chemical production, where a re-supply of resources from Earth is not possible. Here, we provide an overview of currently existing electrolytic energy conversion technologies for space applications such as proton exchange membrane (PEM) and alkaline electrolyzer systems. We discuss the governing interfacial processes in these devices influenced by reduced gravitation and provide an outlook on future applications of electrolysis systems in, e.g., in-situ resource utilization (ISRU) technologies. A perspective of computational modelling to predict the impact of the reduced gravitational environment on governing electrochemical processes is also discussed and experimental suggestions to better understand efficiency-impacting processes such as gas bubble formation and detachment in reduced gravitational environments are outlined. KW - Elektrolyse KW - electrolysis Y1 - 2022 UR - https://www.nature.com/articles/s41526-022-00239-y#citeas U6 - https://doi.org/10.1038/s41526-022-00239-y SN - 2373-8065 VL - 8 ER - TY - GEN A1 - Höhne, Olaf A1 - Lechner, Stefan A1 - Schreiber, Matthias A1 - Krautz, Hans Joachim T1 - Drying of Lignite in a Pressurized Steam Fluidized Bed - Theory and Experiments Y1 - 2010 ER - TY - GEN A1 - Thummar, Krunalkumar A1 - Abang, Roger A1 - Menzel, Katharina A1 - Groot, Matheus Theodorus de T1 - Coupling a Chlor-Alkali Membrane Electrolyzer Cell to a Wind Energy Source: Dynamic Modeling and Simulations T2 - Energies N2 - Renewable energy sources are becoming a greater component of the electrical mix, while being significantly more volatile than conventional energy sources. As a result, net stability and availability pose significant challenges. Energy-intensive processes, such as chlor-alkali electrolysis, can potentially adjust their consumption to the available power, which is known as demand side management or demand response. In this study, a dynamic model of a chlor-alkali membrane cell is developed to assess the flexible potential of the membrane cell. Several improvements to previously published models were made, making the model more representative of state-of-the-art CA plants. By coupling the model with a wind power profile, the current and potential level over the course of a day was simulated. The simulation results show that the required ramp rates are within the regular operating possibilities of the plant for most of the time and that the electrolyte concentrations in the cell can be kept at the right level by varying inlet flows and concentrations. This means that a CA plant can indeed be flexibly operated in the future energy system. Y1 - 2022 U6 - https://doi.org/10.3390/en15020606 SN - 1996-1073 VL - 15 IS - 2 SP - 1 EP - 26 ER - TY - GEN A1 - Dahash, Abdulrahman A1 - Mieck, Sebastian A1 - Ochs, Fabian A1 - Krautz, Hans Joachim T1 - A comparative study of two simulation tools for the technical feasibility in terms of modeling district heating systems: An optimization case study T2 - Simulation Modelling Practice and Theory N2 - District heating dynamic models arise as an alternative approach to in-situ experimental investigations. The main advantage of dynamic modeling and simulation is the possibility to avoid technical and operational risks that might occur during in-situ experimental investigations (e.g. heat demand is not met, damages in the energy systems etc.). Within this study, the authors present two models for an existing district heating system in Cottbus, Germany. One model is developed using the tool EBSILON Professional, while the other one is developed using the Simscape toolbox for physical modeling in Matlab/Simulink. The models were experimentally validated against measured data from the considered district heating system. The results show that the Simscape model has a better fit and better response than the EBSILON model. Yet, some discrepancies were found between the measured and the simulated data and, therefore, the uncertainties of the models were addressed. A comparative study between both tools is presented. The EBSILON models permit only unidirectional flow, whereas the Simscape toolbox permits reverse flow. Nevertheless, the EBSILON model outperforms the Simscape model in computation time. In addition, this study presents an approach for dynamic thermo-hydraulic modeling of district heating networks. This approach is utilized to examine the role of district heating networks as heat storage as an optimization configuration. The numerical results show less start-ups for additional heat sources. Yet, higher heat losses from the network are observed due to the installation of unburied pipelines. KW - Dynamic thermo-hydraulic modeling and simulation KW - Simscape KW - EBSILON Professional KW - District heating systems KW - Heating network as heat storage Y1 - 2019 U6 - https://doi.org/10.1016/j.simpat.2018.11.008 SN - 1569-190X VL - 91 SP - 48 EP - 68 ER -