© Projektträger Jülich / Forschungszentrum Jülich GmbH

Hot topic: the energy transition

High temperatures, low emissions: the AdReku research project team has developed a burner that can play a significant role in the energy transition of industry. The innovative parts are 3D printed.

The capabilities of the AdReku recuperative burner are demonstrated against a black background in the AdReku research laboratory. The burner is gradually shifted from natural gas to hydrogen, and the flame is measured precisely to ensure the necessary heat and quality needed for industrial processes. A special feature of the AdReku is its ability to use both hydrogen and natural gas flexibly and even in parallel, allowing companies to use natural gas now and simultaneously prepare for the rollout of hydrogen.

The research team from Kueppers Solutions and Gas and Heat Institute Essen (GWI) has put together a key piece of the puzzle for the energy transition with the AdReku burner. As hydrogen is not yet available in sufficient amounts, the burners functions as a bridge between natural gas and hydrogen. A proprietary dual-channel mixing unit enables the seamless transitions between the two energy sources – even when the burner is in active use.

^{Mixing unit for parallel operation with natural gas and hydrogen}

The novel gas mixing system enables fuel gases and air to be combined in a way that generates less nitrogen oxide at high temperatures. This provides a more efficient heat transfer coupled with a low nitrogen oxide output. Optimised burner systems with a preheating temperature of 1,000 degrees Celsius save up to 12 percent more energy than conventional systems (which heat to 600 degrees Celsius) and up to 50 percent more than burners with no preheat function.

The researchers have improved the heat transfer in the burner system by incorporating various materials and restructuring the recuperator. This recuperator is not just produced with a single material, but is assembled using three separate materials in different sections. A ceramic was used near the nozzle, where the temperature is hottest. As the temperature level sinks, stainless steel and copper are added to the mix. This also improves the heat conductivity from material to material, making the heat transfer process much more effective.

^{3D printing enables highly efficient heat exchanger in burner}

The gas mixing system and the heat transfer unit (also known as the recuperator) have been manufactured via 3D printing. This is the only way that the very interlocked structures of the recuperator can be manufactured, explains the research team. These make the transfer areas significantly larger than before, while space remains the same. This allows heat to be transferred more effectively than by models currently on the market.

3D printing is at present still a time-consuming and expensive process, but manufacturing costs are sinking as the technologies improve. The efficient burner systems also use less fuel, allowing savings here to balance out the higher procurement costs once in operation. As the additively manufactured systems are fuel-neutral, widespread industrial use is effortlessly possible.

In 2024, the development team won the Land North Rhine-Westphalia Innovation Prize in the “innovation2business” category for its research work in this area. In 2023, the recuperator burner and thus the idea developed in AdReku was one of three finalists for the German Future Prize.