Objectives and ambition
The THERMAX project aims to develop an innovative heat recovery system from steelmaking processes by integrating Organic Rankine Cycle (ORC) technology and advanced thermal buffer solutions. The primary objective is to enhance energy efficiency in the steel industry by capturing waste heat from three specific sources: hot slag, hot slabs and hot coil. By converting this waste heat into useful energy, the project seeks to address the challenges of energy discontinuity and variability inherent in steelmaking operations, providing a stable and reliable source of power that can be reintegrated into the production process or exported to the grid. Aligned with the European Union’s decarbonization goals, the THERMAX project directly supports the steel sector's commitment to reducing greenhouse gas emissions and transitioning to more sustainable operations. The steel industry is one of the largest industrial emitters of CO₂, accounting for about 7-9% of global direct emissions from fossil fuels. Therefore, innovative approaches to energy recovery, like those proposed in THERMAX, are crucial for meeting the EU’s climate targets, including a 55% reduction in emissions by 2030 and achieving carbon neutrality by 2050. The project aims to capture and repurpose the considerable thermal energy lost during EAF operations, converting it into electricity and usable heat through ORC technology. The integration of thermal energy storage (TES) units, such as phase change materials (PCMs) and advanced sensible heat storage systems, will play a critical role in buffering the intermittent nature of heat generation. These TES systems will stabilize the energy output, allowing the recovered heat to be stored during periods of low demand and released when needed, thus optimizing the efficiency and effectiveness of the heat recovery process. THERMAX also aims to contribute to the circular economy by utilizing steel slag in thermal buffer as thermal storage material and by lowering the reliance on fossil fuels.
Furthermore, the project will explore methods to enhance the performance and scalability of ORC systems in steel production. The ambitions extend to establishing a framework for the wider adoption of these technologies across other energy-intensive industries, setting a benchmark for future heat recovery and energy storage initiatives. The THERMAX project stands out due to its unique integration of multiple heat recovery technologies, ORC, TES, and TEG, into a system that maximizes energy recovery efficiency while addressing the challenges posed by intermittent heat sources in steelmaking. Unlike existing approaches that consider these technologies separately, THERMAX develops a thermal management strategy that optimizes their interaction, ensuring a stable and continuous recovery of energy. The novelty of THERMAX lies in:
1. The first-time industrial application of a slag-based thermal buffer designed to mitigate thermal fluctuations, a key barrier to ORC efficiency in steelmaking.
2. A tailored ORC design capable of operating effectively under highly variable heat profiles, utilizing advanced expansion technology and optimized working fluids to enhance performance.
3. The innovative integration of TEG panels with a thermal buffer, a largely unexplored area in industrial waste heat recovery, which will allow the stabilization of the heat source and maximize the conversion efficiency of TEGs.
4. A modular and scalable approach that enables replication and adaptation of the THERMAX system to different steelmaking configurations and other energy-intensive industries.
By demonstrating the technical and economic feasibility of these advanced heat recovery solutions, THERMAX aims to become a key driver in the industrial decarbonization pathway, contributing to a more sustainable future for the steel industry and beyond. The project also aims to test energy recovery through TEG panels and to provide a theoretical case study and exploitation. Thanks to their simplicity, TEG panels are easily used in various heat recovery scenarios for which the construction of larger and more complex recovery systems are technically and economically inconvenient. Therefore, the project will explore the applicability of this technology for the exploitation of highly discontinuous heat sources such as semi-products and high-temperature production waste.
SO1: Develop and test a system to recover thermal waste energy in the steel industry
The objective involves creating a system that captures waste heat from steel production processes, such as slag cooling, and stores it for consistent use. The system will utilize steel slag as a thermal storage medium, enhancing the recovery and stabilization of waste heat to improve overall energy efficiency in the steel industry.
SO2: Use steel slag as a material for thermal energy storage to enhance sustainability and increase the effective utilization of waste heat
This objective aims to use steel slag, an industrial byproduct, as a thermal energy storage medium to capture and store waste heat from steelmaking processes. The system seeks to improve heat recovery efficiency while repurposing slag, traditionally considered waste. This approach optimizes energy use and promotes sustainability by reducing waste and lowering the steel industry's carbon footprint.
SO3: Use TEG panels to test heat recovery
This objective focuses on testing thermoelectric generator (TEG) panels to capture and convert waste heat into electricity in steel production. The panels will be positioned near high-temperature areas to efficiently convert heat into usable energy, showcasing the feasibility of TEG technology for industrial heat recovery.
SO4: Achieve a reduction in the primary energy demand of steel plants and in the volume of waste slag produced
This objective focuses on reducing the overall primary energy consumption in steel plants by improving heat recovery methods and utilizing waste materials such as steel slag. By optimizing the use of slag as a thermal storage medium and enhancing waste heat capture, the project aims to lower the need for additional energy inputs and minimize slag disposal, contributing to more sustainable and efficient steel production processes.
SO5: Prove the economic and environmental benefits for steel sector
This objective aims to demonstrate the economic and environmental advantages of implementing advanced heat recovery systems and slag utilization in the steel sector. By quantifying the cost savings, energy reductions, and environmental impacts, the project seeks to validate the viability of these technologies as key contributors to sustainable and cost-effective steel production. The analysis will focus on direct economic benefits, such as reduced energy costs, and indirect benefits, such as lower emissions and waste management improvements.