Energy efficiency as a driver of transformation

The ceramics industry is characterized by energy-intensive high-temperature processes such as drying, debinding and sintering. They not only determine product quality, but also the cost structure and CO2 footprint of many companies. At the same time, the demands on ceramic materials are increasing, for example in terms of temperature resistance, thermal shock behaviour, mechanical resilience and functionalization. Added to this are volatile energy prices and the need to make production systems more robust and flexible.

Digital methods as a link between material and process

Dr. Holger Friedrich, Head of the Fraunhofer Center for High-Temperature Lightweight Construction HTL, made it clear that digital methods today are far more than just simulation tools in the narrower sense. Their real added value lies in their ability to combine material development, process design and plant operation. The Fraunhofer HTL in Bayreuth has been pursuing this approach for years. High-temperature materials, ceramic processes, characterization and component development are systematically brought together there.

At the heart of this is the realization that material and process cannot be considered separately. Material properties are not created in isolation, but always in interaction with the manufacturing route, furnace atmosphere, temperature profile and component geometry. This is precisely where digital methods come in: They help to make complex relationships visible, shorten development times and make processes more resilient.
The Integrated Computational Materials Engineering approach is a particularly vivid example of this. Instead of developing materials primarily empirically, it is based on the requirements of the application. The search is not for "possible" materials, but for the composition and microstructure that best fulfills a defined property profile. Multiscale simulations, experimental data, process models and expert knowledge are linked in such a way that material development becomes faster, more targeted and more economical.

Rethinking energy supply: from natural gas to hybrid concepts

A second major topic block of the webinar focused on future developments in energy sources and furnace technologies. Dr. Friedrich showed that the ceramics industry is facing a strategic change of course. Natural gas-powered kilns still dominate, but the requirements for CO2-neutral or at least lower CO2 production methods are increasing. Electric tunnel kilns, biogas, green hydrogen, hybrid kilns and concepts with external hot gas supply are therefore increasingly the subject of research and investment planning.
The key message here was that there will be no universal solution. Techno-economic analyses do help to systematically compare investment costs, operating costs, flexibility and uncertainties. But which concept prevails always depends on the specific process, the location and the available energy sources. In many cases, hybrid heating concepts appear to make particular sense because they allow a flexible response to price developments and political framework conditions.
Michael Müller, Head of Engineering at Rauschert Heinersdorf-Pressig GmbH, directly addressed these considerations in his practical presentation and showed how his company is implementing this transformation in practice. For Rauschert, energy is not just a cost factor, but a strategic component of competitiveness. A company-wide energy management system was therefore set up at an early stage, supplemented by photovoltaics, monitoring of energy consumption and a high level of transparency in the production processes. More than ten megawatts of peak photovoltaics have been installed at the Thuringian sites. This not only makes the company more independent, but also paves the way for future electrification steps.

The webinar made it particularly clear that the greatest potential lies in the thermal processes themselves. Michael Müller presented specific practical examples of this. Rauschert has equipped a new generation of natural gas-fired chamber furnaces with combustion air preheating. Heat from thermal post-combustion is recovered via heat exchangers and fed either into the combustion chamber or directly to the burner. The result: natural gas consumption was demonstrably reduced by more than 30 percent. In view of the very high annual energy consumption, this is a considerable economic and ecological effect.

Michael Müller also emphasized the importance of waste heat recovery. Warm air from kiln processes can be used for space heating, hot water or drying chambers. Especially in an industry in which thermal process steps are closely linked, this form of heat integration opens up additional efficiency potential.

At the same time, it also became clear that technological changes should not be assessed in isolation. The interaction between the kiln atmosphere and the ceramic product is critical for the material. Gas firing introduces moisture into the atmosphere, while the use of hydrogen further increases the water vapor content. This not only affects the service life of kiln linings, but also the properties of the products themselves. Müller pointed out that changes in the strength values of high-purity aluminum oxide have already been observed in a hydrogen atmosphere. This made a central point of the webinar tangible: Energy conversion, material behavior and process stability are inextricably linked.

Simulation and knowledge transfer as operational levers

Another common denominator of both presentations was the role of digital tools in operational process optimization. Friedrich showed how drying, debinding and sintering can be significantly improved with the help of experimental characterization and simulation-based models. Process duration, energy consumption and damage risks can already be evaluated and optimized on the computer. In individual applications, the debinding of ceramic components could be almost halved and made more robust at the same time.
Müller followed this up with examples from industrial practice. Together with the Fraunhofer HTL, Rauschert uses simulation programs to optimize drying and firing curves more quickly, avoid test firings and design processes in a more targeted manner. As a result, digitalization has a direct impact on energy consumption, throughput time and product quality.
Equally important is the preservation of empirical knowledge. In digitally supported production environments, it is not just about data, but also about systematically securing the knowledge of experienced employees, making process steps more transparent and identifying the causes of rejects more quickly. In knowledge-intensive production systems in particular, this is a decisive factor for continuity and competitiveness.

From efficiency project to strategic transformation

The contributions from research and industrial practice by Dr. Holger Friedrich and Michael Müller made it clear that considerable potential can already be tapped today - through optimized firing and drying curves, heat integration, simulation-supported material and process development and the strategic use of new energy sources. The path to the future of the ceramics industry therefore does not lie in individual technology decisions, but in the intelligent linking of energy, material, process and digitalization.
The special value of the webinar lay in the fact that research and practical perspectives did not oppose each other, but complemented each other. Dr. Friedrich's presentation showed the technological and methodological guidelines: digital material development, simulation-supported process design, techno-economic evaluation of new energy sources and the shift in perspective towards adaptive, data-based production systems. Michael Müller's presentation demonstrated that these approaches are not dreams of the future, but are already enabling concrete savings, improved process reliability and well-founded investment decisions today.
This revealed a common leitmotif: energy efficiency has long been more than just a technical optimization issue in the ceramics industry. It is becoming a driver of transformation because it brings together key issues of the future - from energy supply and material development to the digitalization of production and knowledge.