Corrosion-resistant diamond ceramics for chemical plants
In chemical industry, damage caused by corrosion results in high costs and safety risks. In order to avoid corrosion damage, Fraunhofer IKTS, in collaboration with its Fraunhofer AdvanCer Alliance partners, is developing new corrosion- and wear-resistant diamond ceramics. As compared to commercial diamond materials, these new diamond ceramics can be manufactured cost efficiently and in complex geometries using standard ceramic technologies. They can either be produced as compact components or as > 300 to 500 µm thick surface layers in highly stressed component areas. Under hydrothermal conditions or in alkaline media, strengths of more than 400 MPa can be reached. Depending on the microstructural design of the diamond ceramics, their thermal conductivity can be increased up to 500 W/mK offering great potential for heat exchangers.
Highly dynamic microwave heating of reactors
Due to their high geometric surface area and outstanding flow properties, ceramic foams offer several benefits for application in heterogeneously catalyzed reactions. For an efficient reaction control an optimized thermal reactor management is necessary. Microwave heating offers the possibility to respond much more efficiently than with conventional heating methods to discontinuous exhaust gas quantities, application-related fluctuations in the exhaust gas temperature, and dynamic reactions. In cooperation with the Fraunhofer ICT, Fraunhofer IKTS developed a direct microwave reactor heating and a scalable system for microwave-heated reactors. Validation tests in catalytic gas phase reactions, such as CO and HC oxidation and SCR-DeNOx reaction show advantages, specifically in dynamic processes. Thanks to the very rapid heating rates, conversions greater than 90 % could be achieved by heating-up the structured catalyst within a few seconds to the reaction temperature.
Ceramic nanofiltration membranes for desalination and oiling of process water
Ceramic nanofiltration membranes (NF) enable new efficient recycling processes due to their resistance to organic and oil residues, their desalination behavior and their temperature stability. This is confirmed by long-term tests: However, the high production costs for the membranes have argued against the economic treatment of large quantities of water, e.g. in oil production, so far. At IKTS, a scale-up of the membrane surface area initially reduced production costs by approx. 50 % – paving the way for the large-scale use of ceramic NF membranes and the waste water recycling.