Coolbrook RotoDynamic Heater (RDH)

Coolbrook is a Finnish industrial electrification company founded in 2011 in Helsinki to develop a turbine-based heating technology with the University of Oxford and other partners. It targets the fossil-fired kilns, furnaces and heaters that supply high-temperature heat in cement, steel, aluminium and petrochemicals.

The RotoDynamic Heater uses an electric-motor-driven rotor to transfer mechanical energy directly into a process gas, heating it to high temperature without combustion. It is designed for outlet temperatures up to 1,700 C and has been demonstrated above 1,000 C at megawatt scale at the pilot plant in Geleen, Netherlands, which has logged more than 5,000 hours. About 90 to 95% of the electricity becomes process heat. Applications include cement drying, calcination and precalciners, scrap preheating and reheating furnaces in steel, and aluminium heat treatment. A sister product, the RotoDynamic Reactor for electric steam cracking, is in pilot stage.

• Combustion-free heating: transfers electric motor power directly into process gas through a rotor.
• High temperature: designed for outlet temperatures up to 1,700 C, with above 1,000 C proven.
• Megawatt scale: pilot programme with more than 5,000 hours at Brightlands Chemelot Campus since 2022.
• Cement applications: drying, calcination and precalciner heat.
• Metals applications: scrap preheating, hot stove air, DRI reduction gas and reheating furnaces.
• Industrial partners: delivered with ABB, Linde Engineering and other engineering partners.

Cement plants in Vietnam could pilot electric heat for raw meal drying or precalciner stages when paired with renewable power. Steel mills could use electric heating for scrap preheating and reheating furnaces. Aluminium extrusion plants could electrify heat treatment furnaces.

Industrial plants can replace burners in high-temperature steps with an electric heater that has no on-site combustion emissions. The company estimates full deployment of its technology could cut up to 2.4 Gt of CO2 per year, about 7% of global emissions. The RDH has been proven above 1,000 C at megawatt scale and is being delivered with partners such as ABB, which supports integration into existing kilns and furnaces.

Heavy industry is the hardest sector to decarbonise because it needs very high temperatures that heat pumps cannot reach, so direct electric heating is drawing interest from cement and steel majors. Vietnam is a top cement producer and a growing steel maker, and both sectors face carbon border adjustments in export markets and domestic emission inventory rules.

Coolbrook was founded in 2011 in Helsinki, Finland, where it has its headquarters, and operates in the Netherlands, the United Kingdom and India. Its pilot plant opened in 2022 at Brightlands Chemelot Campus in Geleen. In 2025 it signed a delivery agreement with Adani Cement for the first commercial RDH. In 2026 it secured Business Finland funding for steel electrification and won a Reuters Global Energy Award.