PROJECT DESCRIPTION
BACKGROUND
The manufacture of ceramic materials is energy intensive, consumes large amounts of primary raw materials, and produces considerable amounts of greenhouse gases (GHG). Bricks are one of the ceramic products with the highest GHG emissions.
The traditional ceramic process for manufacturing bricks involves a firing stage (conducted at temperatures above 1,000 ºC). A process tested at laboratory scale, called the Alkaline Activation Process (AAP), substitutes the firing stage with a curing stage carried-out at low temperature (<150 ºC). It also allows the recycling of a wide variety of industrial wastes. AAP is based on the dissolution of amorphous silicates and aluminosilicates by an alkaline solution, followed by the polymerisation of the resulting monomers to provide hardness and strength in the material.
OBJECTIVES
The LIFE HYPOBRICK project aimed to demonstrate the feasibility of manufacturing waste-based building products using an extremely low CO2 emission process, called the alkaline-activation process. The project focused on manufacturing bricks made from the new waste-based material in southern and northern European countries (Spain and Germany), in which the wastes available and the constructive requirements are quite different and cover the trends existing in a significant number of European countries.
To achieve its objectives, the project aimed to:
- formulate waste-based mixtures and produce new materials for manufacturing bricks using the AAP that meets all the technical and environmental requirements for international standards and for the market;
- define the operating variables of all the process stages involved in the AAP;
- modify the industrial facilities to allow the manufacturing of the new building material;
- solve the potential production problems that may arise during the pilot and industrial trials in order to obtain building products free of defects and with the required properties;
- obtain a cost-effective and economically-viable building material with an innovative process that favours its commercialisation; and
- make an agreement with another manufacturing company (outside of the project consortium) to replicate and transfer the results before the end of the project.
RESULTS
LIFE HYPOBRICK mostly achieved its main objective. The beneficiaries developed functional waste-based formulations (with some deviations from the originally foreseen ones) for the process, defined the operating variables at laboratory and, at pre-industrial and small-scale industrial, beneficiary MORA modified its industrial facilities to install a prototype allowing small-scale production of AAP bricks. All production problems were solved, making the production feasible. In the German case study, the project was able to obtain a negative but crucial result by confirming that extrusion (main forming process for clay-based bricks) cannot be used with this material. A series of problems related to the casting process were also solved, even if at a handcraft (not industrial) scale.
The project demonstrated that the materials and products obtained comply with the existing environmental and administrative legislation for ceramic (clay) bricks/blocks, but new standards would need to be developed for alkaline activated products. However, a significant reduction of prices vs. regular bricks was not obtained, partly due to the sharp increase in costs of raw materials mainly, and energy, since 2020. Finally, agreements are being reached for using the bricks obtained in pilot projects (including other LIFE projects), thus replicating the results.
In all, the project has largely improved the knowledge and experience for manufacturing bricks based on waste materials using AAP, demonstrating that the technique could stand as an option to contribute to the requirement to energy-intensive industries and to accomplish the climate and environmental guidelines of the EU. However, it has also confirmed that despite promising aspects, the technique proposed still faces several barriers (technological, administrative, economic, etc.), which the project has contributed to partially but not fully overcome.
A total of 15,000 outdoor bricks and around 100 partition blocks were produced by both industrial partners. These 31.4 total tonnes, while sufficient for accomplishing the objectives, are significantly lower than the foreseen 1,000 tonnes. As a result, the actual environmental impact of the project was lower than initially foreseen. The main project climate impact is the reduction of GHG emissions. When its assessment also takes into account the environmental and climate impacts of the production of alkaline activators (for which energy-intensive processes are also required), the overall energy consumption and CO2 emissions reductions amount to c. 60% (vs. more than 90% if only the manufacturing process is taken into account). Due to the absence of the firing stage, air pollutants are avoided. The waste materials finally recycled were glass from cathodic ray tubes (CRT), fly ash and scraps from brick production and from construction and demolition wastes.
The project contributed to the implementation of the EU policy framework for climate and energy in the period from 2020 to 2030 (COM(2014)15), which foresees a cut in GHG emissions by at least 40%; and also to the 2050 Energy Strategy: Energy Roadmap (COM(2011)885 final), which aims at reducing in 2050 the GHG emissions by 80 to 95% (from 1990 levels), in particular in energy-intensive sectors such as the ceramic one. In this sense, the project will also contribute to implementing the EU Climate Law, COM(2020) 80 final "Establishing the framework for achieving climate neutrality and amending Regulation (EU) 2018/1999". Indeed, the project is also in line with the CO2 emission targets in the Spanish and German national climate laws. Additionally, by showcasing the usability of waste materials as input for an industrial process, the project also contributed to the objectives of the "Roadmap for a Resource efficient Europe".
The project was presented to the Technical Working Group reviewing the Best Available Techniques (BAT) Reference Document (BREF) for the ceramics sector, but at the time of submitting the Final Report its inclusion had not been confirmed yet. In Spain, the project has also contributed to the implementation of the new Waste Law 7/2022 by promoting (together with other stakeholders) the end-of-waste status of CRT glass.
