CE 2020 | SMARTREC: High-Temperature Heat Recovery with Molten Salts for Industry
SMARTREC is a European project dedicated to the development of advanced technologies for high-temperature industrial heat recovery. The sectors involved, such as secondary aluminum, ceramics, cement, and glass, are characterized by intermittent, corrosive, and particulate-laden exhaust gases, which make direct utilization of the available heat challenging. SMARTREC proposes a modular platform capable of recovering heat at very high temperatures, integrating Heat Pipe Heat Exchangers (HPHE), a molten salt circuit as a heat transfer fluid, and a thermal storage system that allows a cyclical heat source to be converted into a continuous energy supply. The expected outcome is a significant improvement in industrial process efficiency and a reduction in primary energy consumption.
Engineering, Materials, and Molten Salt Testing
Within the project, Spike plays a central technical role in developing molten salt-based solutions. To enable the selection and validation of high-temperature heat transfer fluids, Spike designed and built the Molten Salt Test Plant (MSTP), an experimental facility dedicated to studying salt mixtures under real operating conditions. As reported in the technical documentation, the plant is designed for temperatures up to 600°C and allows testing fluids with different thermophysical properties, verifying thermal stability, material compatibility, and fluid-dynamic performance. This work is essential to determine which salts are suitable to feed the SMARTREC circuit and to establish the system’s operational limits.
The Molten Salt Test Plant: The Experimental Core of the Project
The MSTP developed by Spike consists of a salt melting and drainage tank, an electrically traced piping network to prevent solidification, a test section dedicated to thermo-fluid dynamic measurements, and a radiant cooling system. Material selection considered the typical high-temperature corrosion challenges: stainless steels such as SS316 were adopted to ensure durability and reliability, while more expensive, higher-performing alloys were considered only theoretically. Initial tests were conducted with a NaNO₃–KNO₃ nitrate mixture, serving as a reference to verify the plant functionality and control logic. These tests confirmed the system’s ability to operate safely and maintain stability even at very high temperatures.
Integration with HPHE and Thermal Storage
Spike’s contribution fits directly within the broader SMARTREC framework. Heat recovered from the Heat Pipe exchangers is transferred to the molten salt circuit, which transports it either to the industrial process or to the thermal storage system. Data collected from MSTP experiments allow verification of the different salt mixtures’ ability to withstand complex thermal cycles, resist corrosion, and maintain stable performance over time. Consortium simulations, based in part on the properties measured by Spike, guide the circuit design, temperature control, and integration with the Dual Media Thermocline (DMT), which compensates for the typical fluctuations in industrial production cycles.
A Platform for Developing the Next Generation of Heat Transfer Fluids
Thanks to Spike’s work, the SMARTREC project now has an experimental platform capable of exploring new molten salt mixtures and testing their behavior under operational conditions that are otherwise difficult to replicate. This enables more accurate evaluation of corrosion effects, pressure drops, compatibility with pumps and valves, and the thermal performance of the fluids. The plant designed by Spike is therefore an essential component in making SMARTREC a technology ready for deployment in real industrial settings, reducing risks and improving system reliability.
The Strategic Value of the Demonstration Plant
Spike’s engineering expertise in designing high-temperature plants and handling complex fluids has enabled SMARTREC to make a significant leap in technology validation. The Molten Salt Test Plant is not merely a test bench but a design and experimental platform that allows the consortium to define practical, industrially scalable, and competitive solutions. Spike’s work represents one of the project’s technological pillars and a key contribution to bringing European industries closer to more efficient, sustainable, and flexible heat recovery.