Porcelain tile production is one of the most energy- and CO₂-intensive processes in the ceramics industry. Firing and sintering dominate the environmental footprint, while incomplete oxidation of organic matter and carbonate disassociation may cause black-core defects inside the tile body (Fig. 1). These defects, strongly influenced by particle morphology, size distribution and composition, reduce product quality and increase re-firing, further raising CO₂ emissions. Although the dry route can reduce energy demand by up to 30%, it is more susceptible to black-core due to reduced homogeneity and oxygen transport limitations (Alves et al., 2025). Previous studies have applied flowsheet simulations (Dyssol) and discrete element modelling (DEM) to porcelain tile manufacturing, optimizing composition and milling strategies, compaction and reduction of energy and emissions in its manufacturing process (Alves et al., 2023; Skorych et al., 2020). However, predictive models for black-core formation, hot cracking and stress states as well as liquid-phase sintering are still missing in such flowsheet approaches.

Two new Dyssol units will be developed. A black-core model based on oxygen diffusion and organics oxidation, driven by kiln temperature and atmosphere profiles. A liquid-phase sintering (LPS) model calibrated with DSC, TGA, DIL and validated by XRD and environmental SEM to capture composition- and phase-dependent shrinkage in-situ. At the particle scale, DEM will simulate the effect of particle morphology and compaction on green density, permeability and will provide an updated sintering model. CFD, on the other hand, will describe oxygen transport and reaction kinetics within porous tiles. The outputs will be condensed into surrogate models (Gaussian Processes and/or Bayesian optimization) for efficient integration into Dyssol and provide a first order approximation. Experimental validation will be carried out at TUHH and UFSC. Compaction, bending trials will support DEM calibration, while Nanoindentation will provide the strain and phase-related softness of each constituting phase for quality assurance. Thermal analysis, XRD, digital and environmental electron-microscopy will provide parameters for the sintering model, verify phase evolution and microstructural data. Targeted kiln experiments varying tile thickness, oxygen availability, and heating rate will supply validation data for the black-core unit. Finally, flowsheet-based sensitivity and uncertainty analyses will quantify the robustness of defect prediction and energy/CO₂ savings.

• Alves, C.L.; Skorych, V.; De Noni Jr., A.; Hotza, D.; González, S.Y.G.; Heinrich, S. Application of flowsheet simulation methodology to improve productivity and sustainability of porcelain tile manufacturing. Machines 11 (2023) 137. https://doi.org/10.3390/machines11020137.
• Alves, C.L.; Skorych, V.; De Noni Jr., A.; Hotza, D.; González, S.Y.G.; Heinrich, S.; Dosta, M. Improving the sustainability of porcelain tile manufacture by flowsheet simulation. Ceramics International 49 (2023) 24581–24597. https://doi.org/10.1016/j.ceramint.2023.01.056.
• Alves, C.L.; Skorych, V.; De Noni Jr., A.; Hotza, D.; González, S.Y.G.; Heinrich, S. Optimizing raw material composition to increase sustainability in porcelain tile production: A simulation-based approach. J. Am. Ceram. Soc. 107 (2024) 2110–2127.
• Skorych, V.; Dosta, M.; Heinrich, S. Dyssol—An open-source flowsheet simulation framework for particulate materials. SoftwareX 12 (2020) 100572. https://doi.org/10.1016/j.softx.2020.100572.
• Dosta, M.; Litster, J.D.; Heinrich, S. Flowsheet simulation of solids processes: Current status and future trends. Adv. Powder Technol. 31 (2020) 947–953. https://doi.org/10.1016/j.apt.2019.12.015.
• Dosta, M.; Skorych, V. MUSEN: An open-source framework for GPU-accelerated DEM simulations. SoftwareX 12 (2020) 100618. https://doi.org/10.1016/j.softx.2020.100618.
• De Noni Jr., A.; Canever, S.B.; Henrique, P.; Ramos, R. Microstructure-oriented porcelain stoneware tile composition design. Ceramics International 49 (2023) 24558–24565. https://doi.org/10.1016/j.ceramint.2022.11.067.
• Alves, C.L., Julia De Oliveira Martins Müller, Agenor De Noni, und Stefan Heinrich. „Challenges and Opportunities for Increase Sustainability and Energy Efficiency in Ceramic Tile Industry“. International Journal of Applied Ceramic Technology 22, Nr. 4 (2025): e15097. https://doi.org/10.1111/ijac.15097.
• Moshnyakov, M. G., und V. Z. Abdrakhimov. „Investigations of the Black Core and Swelling in Firing Porcelain Stoneware“. Glass and Ceramics 76, Nr. 7–8 (2019): 270–73. doi.org/10.1007/s10717-019-00181-8.