Abstract We report the generation of novel carbon micro fibers and foam structures during the pyrolysis of polymer rich waste printed circuit boards (PCBs) in the temperature range of 750 °C to 1550 °C under argon atmosphere. Following initial polymer degradation and the separation of most of the metallic phase, the carbonaceous residue was seen to evolve into a variety of structures. Carbon fibers started to nucleate ~ 1150 °C, had a thickness ranging between 2 and 10 microns, contained up to 95% C with morphologies ranging between tubular, foamy network and fibrous. The chemical compositions of these carbon structures was determined through X-ray microanalysis; the carbon content was close to 90% along with 5-7% oxygen, traces of phosphorus, antimony, tin and copper. The transformation of carbon fibers to a well-defined foam structure was observed at 1250 °C; these structures were found to be stable even at higher temperatures. The formation of carbon foams/fibers was found to be not very sensitive to the relative concentration of oxide impurities present. This study shows that a potentially vast source of carbon could be recovered from the non-metallic fraction of e-waste for applications such as reduction reactions, carburization, metal-carbon composites or as a source of fuel and energy.
Áreas temáticas de ASJC Scopus
- Tecnología del combustible
- Ingeniería energética y tecnologías de la energía
- Ingeniería química (todo)