In this project, various biomasses from the Frankfurt-Rhine-Main region, which are pyrolyzed in carbonization plants, will be analyzed, processed and developed into a reactive additive for cement-based materials. This is to serve as a cement substitute and, with replacement rates of 50 % Portland cement by the additive to be developed, reduce 50 % of the current CO2 emissions from cement production. The use of biomasses has other advantages in addition to CO2 reduction. First, there is no direct dependence on finite resources, as is currently the case with commercial reactive additives for cementitious materials, and second, the biomasses available undergo upcycling in the form of waste substrates and can be used for higher-value applications.
Fatty acids from process water and leachates from waste treatment plants are currently hardly used, in rare cases for biogas production. Used cooking oils and fats from grease separators are currently mainly converted into biodiesel and then used for energy. Biodiesel currently faces various conflicts that prevent its further development. All of these substrates are converted into storable products through conversion to PCM. As a result, larger amounts of carbon that would otherwise be released as CO2 emissions are stored in the PCMs. A corresponding reduction in greenhouse gases from waste treatment plants can thus be expected.
Currently, there are only a few possibilities to utilize lignocellulosic biomass, such as green and shrub cuttings, waste wood, forest residues, and agricultural harvest residues. This biomass is therefore predominantly utilized for energy in biomass CHP plants or even waste-to-energy plants and used to generate electricity and heat. In contrast, carbonization allows this biomass to be put to higher-value use. In this process, the biomass used is converted into a combustible gas, which can continue to be used for energy, and into a vegetable charcoal, which can be used in agriculture, for example.
The coal ashes produced will be modified in the course of the project and used as a reactive additive (PYROCEM additive) for the development of a highly innovative and sustainable concrete construction material (PYROCEM concrete) for concrete components in ground contact used in the civil engineering sector. The application of coal as a pozzolanic material is a development that has been underway for a long time and is driven by various environmental factors affecting climate change.