The stricter requirements for climate neutrality are also forcing manufacturers of ceramic and refractory materials to rethink. This is because the necessary sintering of materials is the most energy-intensive process in ceramic technology. Sintering - a process that is necessary for the production of refractory bricks, tiles, ceramic capacitors, insulators, seals and mixing valves, among other things - involves compacting the microstructure of fine-grained ceramic or metallic materials at high temperatures.
Gas burners are still generally used for this process today. Blast furnace technology in the steel industry is similarly emission-rich. This is why the Institute for Ceramics, Refractories and Composite Materials is researching the development of a new type of hybrid furnace technology for the heat treatment of ceramic and refractory products and for use in metallurgical processes. An energy-efficient sintering technology is to be developed by combining hydrogen-fuelled plasma torches and microwave plasma torches. This is based on green electricity and green hydrogen in order to significantly reduce CO2 emissions. While the hydrogen-powered burners take on the task of preheating up to around 600 degrees Celsius, the microwave plasma burner is used above 600 degrees Celsius up to the sintering temperature, which is between 1,200 and 1,700 degrees Celsius depending on the material.
The researchers have joined forces with industrial partners in Bavaria and Lower Saxony for practical tests and applications of the new technology. As part of the research project, the natural gas burners for heating sintering and melting furnaces are to be replaced by the new hybrid burner technology. As many burners are used in each industrial furnace, this can only be done gradually.
The project, which was launched in 2023, will receive 2.2 million euros in funding from the Federal Ministry for Economic Affairs and Climate Protection until 2027. The institute has been granted a patent for this project after submitting a corresponding application.