Schwarzmayr, P., Birkelbach, F., Walter, H., & Hofmann, R. (2024). Exergy efficiency and thermocline degradation of a packed bed thermal energy storage in partial cycle operation: An experimental study. Applied Energy, 360, Article 122895. https://doi.org/10.1016/j.apenergy.2024.122895 ( reposiTUm)

Huber, D., Birkelbach, F., & Hofmann, R. (2024). Unlocking the potential of synthetic fuel production: Coupled optimization of heat exchanger network and operating parameters of a 1 MW power-to-liquid plant. Chemical Engineering Science, 284, Article 119506. https://doi.org/10.1016/j.ces.2023.119506 ( reposiTUm)

Huber, D., Birkelbach, F., & Hofmann, R. (2024). Evaluating synthetic fuel production: A case study on the influence of electricity and CO₂ price variations. Case Studies in Thermal Engineering, 61, Article 104975. https://doi.org/10.1016/j.csite.2024.104975 ( reposiTUm)

Birkelbach, F., Huber, D., & Hofmann, R. (2024). Piecewise linear approximation for MILP leveraging piecewise convexity to improve performance. COMPUTERS & CHEMICAL ENGINEERING, 183, Article 108596. https://doi.org/10.1016/j.compchemeng.2024.108596 ( reposiTUm)

Sao Paulo Ruela, V., Van Beurden, P., Luchini, B., Hofmann, R., & Birkelbach, F. (2024). Optimizing the Steel Ladle Thermal Management: Toward a Sustainable and Cost‐Effective Ladle Fleet Logistics. Steel Research International, Article 2400616. https://doi.org/10.34726/7340 ( reposiTUm)

Wiens, M., Steindl, G., Tubeuf, C., Birkelbach, F., Burfeind, J., & Meyer, T. (2024). DigiWind-An Open-Source Digital Twin Framework for Wind Energy Systems. IEEE Access, 12, 84046–84063. https://doi.org/10.1109/ACCESS.2024.3414335 ( reposiTUm)

Kasper, L., Schwarzmayr, P., Birkelbach, F., Javernik, F., Schwaiger, M., & Hofmann, R. (2024). A digital twin-based adaptive optimization approach applied to waste heat recovery in green steel production: Development and experimental investigation. Applied Energy, 353(B), Article 122192. https://doi.org/10.1016/j.apenergy.2023.122192 ( reposiTUm)

Schwarzmayr, P., Birkelbach, F., Walter, H., Javernik, F., Schwaiger, M., & Hofmann, R. (2024). Packed bed thermal energy storage for waste heat recovery in the iron and steel industry: A cold model study on powder hold-up and pressure drop. Journal of Energy Storage, 75, Article 109735. https://doi.org/10.1016/j.est.2023.109735 ( reposiTUm)

Tubeuf, C., Birkelbach, F., Maly, A., & Hofmann, R. (2023). Increasing the Flexibility of Hydropower with Reinforcement Learning on a Digital Twin Platform. Energies, 16(4), Article 1796. https://doi.org/10.3390/en16041796 ( reposiTUm)

Huber, D., Birkelbach, F., & Hofmann, R. (2023). HENS Unchained: MILP Implementation of Multi-Stage Utilities with Stream Splits, Variable Temperatures and Flow Capacities. Energies, 16(12), Article 4732. https://doi.org/10.3390/en16124732 ( reposiTUm)

Ruela, V., Van Beurden, P., Sinnema, S., Hofmann, R., & Birkelbach, F. (2023). A global solution approach to the energy-efficient ladle dispatching problem with refractory temperature control. IEEE Access, 11, 137718–137733. https://doi.org/10.1109/ACCESS.2023.3339392 ( reposiTUm)

Schwarzmayr, P., Birkelbach, F., Walter, H., & Hofmann, R. (2023). Standby efficiency and thermocline degradation of a packed bed thermal energy storage: An experimental study. Applied Energy, 337, Article 120917. https://doi.org/10.1016/j.apenergy.2023.120917 ( reposiTUm)

Kasper, L., Birkelbach, F., Schwarzmayr, P., Steindl, G., Ramsauer, D., & Hofmann, R. (2022). Toward a Practical Digital Twin Platform Tailored to the Requirements of Industrial Energy Systems. Applied Sciences, 12(14), Article 6981. https://doi.org/10.3390/app12146981 ( reposiTUm)

Wartha, E.-M., Birkelbach, F., Bösenhofer, M., & Harasek, M. (2022). Enhanced kinetic model identification for gas–solid reactions through Computational Fluid Dynamics. Chemical Engineering Journal, 430(2), Article 132850. https://doi.org/10.1016/j.cej.2021.132850 ( reposiTUm)

Halmschlager, V., Birkelbach, F., & Hofmann, R. (2021). Optimizing the utilization of excess heat for district heating in a chipboard production plant. Case Studies in Thermal Engineering, 25, Article 100900. https://doi.org/10.1016/j.csite.2021.100900 ( reposiTUm)

Gravogl, G., Birkelbach, F., Müller, D., Lengauer, C., Weinberger, P., & Miletich, R. (2021). Pressure Dependence of the Low Temperature Carbonation Kinetics of Calcium Oxide for Potential Thermochemical Energy Storage Purposes and Sustainable CO₂ Fixation. Advanced Sustainable Systems, 2100022, 1–11. http://hdl.handle.net/20.500.12708/137570 ( reposiTUm)

Sögütoglu, L.-C., Birkelbach, F., Werner, A., Fischer, H., Huinink, H., & Adan, O. (2020). Hydration of salts as a two-step process: Water adsorption and hydrate formation. Thermochimica Acta, 695(178819), 178819. https://doi.org/10.1016/j.tca.2020.178819 ( reposiTUm)

Kasper, L., Bacher, T., Birkelbach, F., & Hofmann, R. (2020). Digitalization possibilities and the potential of the Digital Twin for steam supply systems. VGB PowerTech, 11, 45–52. http://hdl.handle.net/20.500.12708/141818 ( reposiTUm)

Birkelbach, F., Deutsch, M., & Werner, A. (2020). The effect of the reaction equilibrium on the kinetics of gas-solid reactions - A non-parametric modeling study. Renewable Energy, 152, 300–307. https://doi.org/10.1016/j.renene.2020.01.033 ( reposiTUm)

Huber, C., Jahromy, S. S., Birkelbach, F., Weber, J., Jordan, C., Schreiner, M., Harasek, M., & Winter, F. (2020). The multistep decomposition of boric acid. Energy Science and Engineering, 8(5), 1650–1666. https://doi.org/10.1002/ese3.622 ( reposiTUm)

Huber, C., Setoodeh Jahromy, S., Birkelbach, F., Weber, J., Jordan, C., Schreiner, M., Harasek, M., & Winter, F. (2020). The multistep decomposition of boric acid. Energy Science and Engineering, 8(5), 1650–1666. https://doi.org/10.1002/ese3.622 ( reposiTUm)

Birkelbach, F., Deutsch, M., Flegkas, S., Winter, F., & Werner, A. (2019). NPK 2.0: Introducing tensor decompositions to the kinetic analysis of gas-solid reactions. International Journal of Chemical Kinetics, 51(4), 280–290. https://doi.org/10.1002/kin.21251 ( reposiTUm)

Hofmann, R., Halmschlager, V., Koller, M., Scharinger-Urschitz, G., Birkelbach, F., & Walter, H. (2019). Comparison of a Physical and a Data-Driven Model of a Packed Bed Regenerator for Industrial Applications. Journal of Energy Storage, 23, 558–578. https://doi.org/10.1016/j.est.2019.04.015 ( reposiTUm)

Setoodeh Jahromy, S., Birkelbach, F., Jordan, C., Huber, C., Harasek, M., Werner, A., & Winter, F. (2019). Impact of Partial Pressure, Conversion, and Temperature on the Oxidation Reaction Kinetics of Cu2O to CuO in Thermochemical Energy Storage. Energies, 12(3), 1–15. https://doi.org/10.3390/en12030508 ( reposiTUm)

Flegkas, S., Birkelbach, F., Winter, F., Groenewold, H., & Werner, A. (2019). Profitability Analysis and Capital Cost Estimation of a Thermochemical Energy Storage System Utilizing Fluidized Bed Reactors and the Reaction System MgO/Mg(OH)2. Energies, 12(24), 1–16. https://doi.org/10.3390/en12244788 ( reposiTUm)

Flegkas, S., Birkelbach, F., Winter, F., Freiberger, N., & Werner, A. (2018). Fluidized bed reactors for solid-gas thermochemical energy storage concepts - Modelling and process limitations. Energy, 143, 615–623. https://doi.org/10.1016/j.energy.2017.11.065 ( reposiTUm)

Birkelbach, F., Deutsch, M., Flegkas, S., Winter, F., & Werner, A. (2018). A higher-order generalization of the NPK-method. Thermochimica Acta, 661, 27–33. https://doi.org/10.1016/j.tca.2018.01.005 ( reposiTUm)

Deutsch, M., Birkelbach, F., Knoll, C., Harasek, M., Werner, A., & Winter, F. (2017). An extension of the NPK method to include the pressure dependency of solid state reactions. Thermochimica Acta, 654, 168–178. https://doi.org/10.1016/j.tca.2017.05.019 ( reposiTUm)

Huber, D., Birkelbach, F., & Hofmann, R. (2024). Network optimization for sustainable integration of decentralized biogas production. In Proceedings of the ASME 2024 18th International Conference on Energy Sustainability ES2024. ASME 2024 18th International Conference on Energy Sustainability, Anaheim, California, United States of America (the). https://doi.org/10.1115/ES2024-121756 ( reposiTUm)

Zabik, G., Birkelbach, F., & Hofmann, R. (2024). Decarbonizing the Steel Processing Industry: A MILP-Based Assessment of Electrification and Hydrogen for Hot Rolling. In ASME 2024 18th International Conference on Energy Sustainability. ASME 2024 18th International Conference on Energy Sustainability, Anaheim, United States of America (the). https://doi.org/10.1115/ES2024-130999 ( reposiTUm)

Azizi, F., Gennesson, M., Wagner, D., Birkelbach, F., & Hofmann, R. (2024). Enhancing Steel Ladle Thermal Management: Implementing Model Order Reduction Approach  for Temperature Monitoring. In ICR International Colloquium on Refractories: Proceedings (pp. 175–178). European Centre for  Refractories gGmbH. ( reposiTUm)

Freiin von Tubeuf, C. S., aus der Schmitten, J., Hofmann, R., Heitzinger, C., & Birkelbach, F. (2024). Improving Control of Energy Systems With Reinforcement Learning: Application to a Reversible Pump Turbine. In Proceedings of the ASME 2024 18th International Conference on Energy Sustainability ES2024. 18th International Conference on Energy Sustainability (ASME ES 2024), Anaheim, United States of America (the). https://doi.org/10.1115/ES2024-122475 ( reposiTUm)

Zabik, G., Birkelbach, F., & Hofmann, R. (2023). Qualitative Comparison of On-Site Production of Hydrogen and Its Synthesis Products for Steel Processing Industry. In Proceedings of ECOS 2023 - The 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (pp. 2514–2522). https://doi.org/10.52202/069564-0226 ( reposiTUm)

Schwarzmayr, P., Birkelbach, F., Walter, H., & Hofmann, R. (2023). Study on the Standby Characteristics of a Packed Bed Thermal Energy Storage: Experimental Results and Model Based Parameter Optimization. In ASME Power Applied R&D 2023. ASME Power Applied R&D 2023, Long Beach, California, United States of America (the). https://doi.org/10.1115/POWER2023-108578 ( reposiTUm)

Tubeuf, C., Birkelbach, F., Maly, A., Krause, M., & Hofmann, R. (2023). Enabling Reinforcement Learning for Flexible Energy Systems Through Transfer Learning on a Digital Twin Platform. In 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2023) (pp. 3218–3228). https://doi.org/10.52202/069564-0289 ( reposiTUm)

Zechner, N., Birkelbach, F., & Hofmann, R. (2023). Modeling the thermal processes in a short cycle press to improve product quality. In Proceedings of the International Panel Products Symposium 2023 (pp. 129–138). http://hdl.handle.net/20.500.12708/189395 ( reposiTUm)

Huber, D., Werdinig, K., Birkelbach, F., & Hofmann, R. (2023). Highly efficient heat integration of a power-to-liquid process using MILP. In Proceedings of ECOS 2023 – 36th lnternational Conference on Efficiency, Cost, Optimization, Simulation and Environmental lmpact of Energy Systems. 36th lnternational Conference on Efficiency, Cost, Optimization, Simulation and Environmental lmpact of Energy Systems, Las Palmas de Gran Canaria, Spain. ( reposiTUm)

Birkelbach, F., Kasper, L., Schwarzmayr, P., & Hofmann, R. (2023). Operation planning with thermal storage units using MILP: Comparison of heuristics for approximating non-linear operating behavior. In A. M. Blanco-Marigorta, B. Del Rio Gamero, N. Melian Martel, & N. El Kori (Eds.), Proceedings of ECOS 2023. 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (pp. 1279–1284). ULPGC. http://hdl.handle.net/20.500.12708/187709 ( reposiTUm)

Huber, D., Birkelbach, F., & Hofmann, R. (2023). Non-Pareto optimal solutions as enablers for versatile heat exchanger networks. In A. Kokossis, M. Georgiadis, & E. Pistikopoulos (Eds.), Proceedings of the 33rd European Symposium on Computer Aided Process Engineering (ESCAPE33). Elsevier B.V. http://hdl.handle.net/20.500.12708/187039 ( reposiTUm)

Schwarzmayr, P., Birkelbach, F., Kasper, L., & Hofmann, R. (2022). Development of a Digital Twin Platform for Industrial Energy Systems. In Jinyue Yan (Ed.), Energy Proceedings Volume 25: Accelerated Energy Innovations and Emerging Technologies. Scanditale AB. http://hdl.handle.net/20.500.12708/136382 ( reposiTUm)

Birkelbach, F., Deutsch, M., & Werner, A. (2020). The effect of the reaction equilibrium on the kinetics of gas-solid reactions - A non-parametric modeling study. In Edicions de la Universitat de Lleida (pp. 161–171). http://hdl.handle.net/20.500.12708/68179 ( reposiTUm)

Wesenauer, F., Jordan, C., Birkelbach, F., Pichler, M., Harasek, M., & Winter, F. (2019). Pore-forming additives in brick production and their behaviour in the burning process - first results of an ongoing investigation. In Conference Proceedings (pp. 56–59). http://hdl.handle.net/20.500.12708/50469 ( reposiTUm)

Halmschlager, V., Koller, M., Birkelbach, F., & Hofmann, R. (2019). Grey Box Modeling of a Packed-Bed Rengenerator Using Recurrent Neural Networks. In IFAC Papers online (pp. 1341–1346). http://hdl.handle.net/20.500.12708/68033 ( reposiTUm)

Flegkas, S., Birkelbach, F., Winter, F., Haider, M., & Werner, A. (2018). Simulation Study of the Bubble Behavior in Fluidized Bed Reactors with lnternal Horizontal Tubes and their effect on Thermochemical Heat Storage Systems. In Proceedings (p. 8). http://hdl.handle.net/20.500.12708/50198 ( reposiTUm)

Flegkas, S., Birkelbach, F., Werner, A., Freiberger, N., Haider, M., Winter, F., & Weinberger, P. (2017). Thermochemical Energy Storage Concept based on a Reactor Cascade with different Storage Materials. In Proceeding (p. 14). http://hdl.handle.net/20.500.12708/50047 ( reposiTUm)

Zechner, N., Birkelbach, F., Schwarzmayr, P., & Hofmann, R. (2024, July). Determination of heat transfer coefficients in wood-based panel finishing [Conference Presentation]. 17th International Conference on Advanced Computational Engineering and Experimenting (ACEX2024), Barcelona, Spain. ( reposiTUm)

Frenzel, P., Birkelbach, F., Koch, S., Arthofer, F., & Hofmann, R. (2024, July 4). Prediction of Residence Time Distribution of a Single-Screw Rubber Extruder by Parameterising the Transfer Function using Experimental Data [Conference Presentation]. 17th International Conference on Advanced Computational Engineering and Experimenting (ACEX2024), Barcelona, Spain. ( reposiTUm)

Sao Paulo Ruela, V., Van Beurden, P., Hofmann, R., & Birkelbach, F. (2024, July). A heuristic for fitting piecewise-linear models of bivariate functions with simplices and its application to an industrial use case [Conference Presentation]. EURO24, Copenhagen, Denmark. https://doi.org/10.5281/ZENODO.12760505 ( reposiTUm)

Freiin von Tubeuf, C. S., Birkelbach, F., & Hofmann, R. (2023, May 26). Using Reinforcement Learning to Optimize Operational Strategies for Wind Energy Systems [Conference Presentation]. WESC 2023, Glasgow, United Kingdom of Great Britain and Northern Ireland (the). https://doi.org/10.34726/4242 ( reposiTUm)

Birkelbach, F. (2023, May 9). Digital twins as enablers for waste heat recovery with thermal energy storage [Conference Presentation]. Energy Future Industry 2023, Göteborg, Sweden. ( reposiTUm)

Birkelbach, F. (2023, May 9). Optimization Strategies for Industrial Excess Heat Recovery [Conference Presentation]. Energy Future Industry 2023, Göteborg, Sweden. ( reposiTUm)

Sao Paulo Ruela, V., Van Beurden, P., Sinnema, S., Hofmann, R., & Birkelbach, F. (2023, September 27). Advanced Analytics Applied to Improve the Energy Efficiency of Steel Ladle Logistics [Poster Presentation]. UNITECR23, Frankfurt, Germany. https://doi.org/10.5281/ZENODO.8375248 ( reposiTUm)

Birkelbach, F. (2022). Digitalisierung, künstliche Intelligenz und verwandte Technologien für Energieeffizienz und Reduktion der Treibhausgasemissionen in der Industrie. Webinar “Flexibilisierung industrieller Energiesysteme,” Webinar, Austria. http://hdl.handle.net/20.500.12708/95663 ( reposiTUm)

Birkelbach, F., & Hofmann, R. (2022). Digital twins in industrial energy systems: Insights from IEA IETS Task XVIII Subtask 2. ISEC 2022 - 2nd International Sustainable Energy Conference, Graz, Austria. http://hdl.handle.net/20.500.12708/95664 ( reposiTUm)

Freiin von Tubeuf, C. S., Birkelbach, F., & Maly, A. (2022, November 9). Increasing the flexibility of hydropower with reinforcement learning on a digital twin platform [Conference Presentation]. 21st International Seminar on Hydropower Plants, Laxenburg, Austria. ( reposiTUm)

Halmschlager, V., Birkelbach, F., & Hofmann, R. (2021). Digitales Arbeiten und nachhaltiges Produzieren. Digital Days 2021, Genial Digital: Das nachhaltige Wien, Wien, Austria. http://hdl.handle.net/20.500.12708/95665 ( reposiTUm)

Gravogl, G., Birkelbach, F., Müller, D., Lengauer, C., Werner, A., Weinberger, P., & Miletich, R. (2020). Pressure dependence of low temperature carbonation of CaO under water saturation. 35#^{th} Workshop on Novel Materials and Superconductors 2020, JUFA Schladming, Austria. http://hdl.handle.net/20.500.12708/101434 ( reposiTUm)

Birkelbach, F., Fluch, J., Jentsch, R., Kasper, L., Knapp, A., Knöttner, S., Kurz, T., Paczona, D., Schwarzmayr, P., Sharma, E., Tahir, A. J., Tugores, C. R., & Zawodnik, V. (2022). Digital Twins: Terms & Definitions. TU Wien. https://doi.org/10.34726/3802 ( reposiTUm)

Birkelbach, F., Fluch, J., Jentsch, R., Kasper, L., Knapp, A., Knöttner, S., Kurz, T., Paczona, D., Schwarzmayr, P., Sharma, E., & Zawodnik, V. (2022). Existing Digital Twin Solutions: Report on questionnaire. https://doi.org/10.34726/3803 ( reposiTUm)

Jordan, C., Setoodeh Jahromy, S., Azam, M., Harasek, M., Winter, F., Vogtenhuber, H., Birkelbach, F., & Werner, A. (2020). Waste2Storage - Potenzial der Flugasche als thermochemischer Energie- & CO2 Speicher. http://hdl.handle.net/20.500.12708/40223 ( reposiTUm)

Huber, D., & Birkelbach, F. (2022, October). Grüne Kraftstoffe für Graue Mobilität. Bulletin. Alumni-Magazin der TU Wien, Nr 53, Oktober 2022, 10–12. http://hdl.handle.net/20.500.12708/136006 ( reposiTUm)

Birkelbach, F. (2020). Non-parametric kinetic modeling of gas-solid reactions for thermochemical energy storage [Dissertation, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2020.82863 ( reposiTUm)

Birkelbach, F. (2016). Simulation of a fluidized bed regenerative heat exchanger [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2016.30240 ( reposiTUm)