While the use of carbon fiber reinforced plastics (CFRP) has steadily increased in recent years, the disposal situation of non-recyclable end-of-life fibers is unresolved. The process conditions of the established thermal waste treatment methods do not reach the process conditions necessary for the complete conversion of the fiber waste, which partly leads to technical problems up to plant shutdown. In addition, incomplete conversion can result in emission of respirable fibers (so-called WHO fibers). Therefore the development of new process principles for the specific treatment of waste containing carbon fibers is necessary.
The aim of the project is to create the basis for the development of thermal disposal processes for waste containing carbon fibres on an industrial scale. These will be investigated by means of combustion experiments in circulating fluidized bed and tubular reactors. In the test series scaled from laboratory to semi-industrial scale, the process conditions and process engineering requirements for efficient and environmentally friendly fiber treatment are determined. In addition to the thermochemical conversion process, the emission reduction and in particular, the effectiveness of particle separators against unburned CFRP dusts is also investigated and their recirculation to complete fiber conversion is tested. The handling of the materials and the avoidance of respirable WHO fibers also plays an important role, which is why appropriate occupational health and safety concepts are being developed.
Besides project coordination, TEER's work is mainly focused on the design and optimization of laboratory and pilot plant tests for CFRP conversion in tubular reactors as well as the characterization of the separation behavior of common particle cleaning processes against fiber containing dusts by exhaust gas measurements and analysis of process residues. Project partner for the investigation of the conversion behaviour in fluidised bed reactors is the Chair of Energy Process Engineering (EVT) at the Technical University of Dresden (TU Dresden). The project is funded for two and a half years by the Federal Ministry of Economics and Climate Action via the research association DECHEMA Gesellschaft für Chemische Technik und Biotechnologie e.V. of the Industrielle Gemeinschaftsforschung (IGF) of AiF.