GreenBricks – CO₂-neutral brick factory
Currently, as is the case in other energy-intensive sectors, high-temperature tunnel kilns fired with natural gas are used for firing products in the industrial brick and heavy clay industry. The production processes show correspondingly high energy-related CO₂ emissions. In addition, there are significant process-related CO₂ emissions, due to the release of carbonates contained in the clay and the combustion of additives.
A promising environmentally friendly alternative is electric kilns powered by green electricity. To date, however, this technology has only been implemented for small to medium-sized plants and batch processes. There are also promising carbon neutral alternatives for porosification agents, which are necessary to achieve good thermal as well as sound insulation, and which still need to be tested and evaluated in large-scale applications.
„We are aware of our responsibility as market leader. In the GreenBricks project, we are setting new global standards in industrial brick production with regard to energy efficiency and CO₂-emissions.“
In order to decarbonise the industrial production of bricks, GreenBricks pursues the following goals:
- holistic optimisation of the brick manufacturing process.
- development of new CO₂-neutral clay mixtures considering site-specific product and clay properties as well as industrial production environments.
- optimisation of the overall energy efficiency in the dryer - burner - heat pump heat network and adaptation of the brick drying technology to the new electric kiln and clay recipe.
- optimisation of the operation of the novel, high-efficiency, high-temperature tunnel kiln.
- scaling up the concept and evaluating its transferability to other production sites and technology transfer to related sectors.
- securing social acceptance and trust in the developed solutions.
In order to optimise the process of brick production holistically, various tools / technologies are being developed in GreenBricks. This includes, above all, the creation of a digital twin of the dryer-burner-heat pump heat network as well as a model for techno-economic optimisation at the plant level.
In a further step, new recipes for clay mixtures with a minimal CO₂ footprint will be developed. This requires sophisticated screening, testing and optimisation procedures. The newly developed mixtures are tested and optimised in the brick molding/extrusion process, in the dryer and in the kiln under real production conditions and at various Wienerberger locations.
To optimise the overall energy efficiency in the dryer - burner - heat pump heat network, the design of the tunnel dryer and its internal and external heat recovery technologies such as e.g. compression heat pumps will be analysed and adapted.
The gas-fired burner will be dismantled and replaced by a new type of electrically fired high-temperature kiln. The heat distribution in the kiln will be optimised at different levels using various models to be developed in the project. The new kiln will then be commissioned step by step and tested and evaluated up to a production capacity of 300 tons of bricks/day.
In a further step, the introduction of the technologies at plant level within the Wienerberger Group will be prepared and techno-economic site analyses of at least five plants in three countries will be carried out. In addition, CFD models will be used to evaluate the extent to which the knowledge gained in the project can be technically transferred to the electrification of batch and continuous kilns for the manufacture of other ceramic products or in other sectors.
Finally, an intensive dialog with relevant industrial, public, and political stakeholders is planned. This is to ensure that the concepts/technologies developed are socially accepted, ecologically compatible and economically feasible. In addition, extensive networking activities are planned to promote a broad use of the project results and findings in other ceramic sectors as well as industries that also use gas-fired burners on an industrial scale, and to initiate further research projects.
Milestones
- Brick plant digitally mapped, and model evaluated for techno-economic optimization.
- New clay mixtures successfully tested for various production sites.
- Adaptation of dryer control system completed, and expanded dryer tunnel successfully commissioned.
- High-efficiency, electrically operated tunnel kiln commissioned and successfully started up.
- Techno-economic evaluation of further Wienerberger sites and know-how transfer within and outside the Wienerberger group successfully carried out.
The project should lead to the following results:
- Enabling a holistic view of the entire production process through its further digitalisation.
- New, robust, clay mixtures with no or minimal CO₂ content.
- World's first large-scale demonstration of a CO₂-neutral kiln for brick firing, leading to a reduction of CO₂ emissions at the demo site by up to 88%.
- Roll-out concepts for at least five additional Wienerberger sites as well as broad knowledge about the technical feasibility of electrifying various burner types for the production of different products in the ceramics industry and beyond.
- Broad public awareness and acceptance of the research work carried out and results achieved.
