TECNALIA transforms industrial waste heat into useful energy

The technology centre has launched Revalheat, a start-up capable of reintegrating heat that is currently wasted back into production processes, reducing fossil fuel consumption and CO₂ emissions

TECNALIA continues to work towards the decarbonisation of industry and, to this end, has developed a technology capable of harnessing waste heat from production processes and converting it into reusable energy. This technology forms the basis of the start-up Revalheat, which focuses on developing solutions to recover and make better use of low-temperature industrial waste heat that is currently lost.

The company was established with the aim of converting this waste heat into useful energy for industrial processes themselves, helping to increase the energy efficiency of facilities, reduce their dependence on fossil fuels and advance the decarbonisation of energy-intensive sectors.

“Revalheat was created to address a very specific challenge: harnessing low-temperature waste heat that, until now, has been difficult to recover. Our technology makes it possible to raise its temperature level and reintegrate it into the industrial process, reducing energy consumption and the associated emissions,” explains Jesús Isoird, Director of Renewables and Thermal Efficiency at TECNALIA.

The new start-up is based on the Absorption Heat Transformer, known as AHT, also referred to as a type II absorption heat pump. This thermodynamic technology uses waste heat as its main energy source, raises its temperature level and enables it to be reintegrated into the production process at a usable temperature. In this way, Revalheat transforms a resource that is currently lost into an energy and economic asset for industry.

A new route to industrial decarbonisation

A significant proportion of the energy consumed by industry ultimately ends up being released as heat. However, when this waste heat is at a low temperature, recovering and reusing it using conventional solutions can be complex or even unfeasible.

The Absorption Heat Transformer developed by Revalheat makes it possible to recover waste heat at inlet temperatures of between 70 and 110 °C and raise its temperature to 120–150 °C, meeting the thermal demands of the industrial process itself or requirements associated with low-pressure steam. This recovery reduces the amount of external energy required and, consequently, lowers fossil fuel consumption and CO₂ emissions.

The technology is based on an absorption cycle that uses water and lithium bromide as working fluids. The system consumes very little electricity to raise the temperature, as it primarily uses the waste thermal energy already available at the facility and the exothermic process inherent in absorption. With a thermal coefficient of performance (COP) of approximately 0.5, the device upgrades around half of the incoming waste heat, raising its temperature by 30–50 K without the need for additional energy.

Revalheat is also working to optimise its control systems, both for the operation of the transformer itself and for its integration into production processes. This control is essential in order to adapt the system’s response to the operational and energy variations of each industrial facility.

The technology’s scalable design enables solutions to be developed from approximately 200 kW of capacity through to larger-scale industrial projects.

Its viability has already been demonstrated in real industrial environments as part of various European projects, where improvements in energy efficiency, emission reductions and savings in operating costs have been achieved, with investment payback periods of between two and four years. This enables industrial companies to anticipate new regulatory requirements, reduce the climate impact of their processes and improve the environmental performance of their facilities without compromising operational efficiency.

With this launch, TECNALIA is promoting a new solution aimed at addressing one of industry’s main energy challenges: harnessing low-temperature waste heat and reducing the amount of external energy required to maintain production processes. REVALHEAT aims to carry out techno-economic studies and manufacture and install absorption heat transformers.