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)

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)

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., & 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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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., 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. (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)

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. ( 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)

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)

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)

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. ( 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)

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)

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)

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)

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