Migration, transformation and release of pollutants during pyrolysis of the waste electronic plastics

Due to the increasing amount of waste electronic plastics and electrical equipment (WEEE), waste electronic plastics, which contain brominated flame retardants (BFR) materials, have become one of the emerging and fastest-growing waste streams and a major obstacle to recycling. Pyrolytic recovery has been proposed as an environmentally friendly method for clean fuel production or chemical feedstock for these e-waste plastics. This paper summarizes the current pyrolysis technologies for the recovery of BFR-plastics, aiming to solve the energy crisis and environmental degradation caused by BFR-plastics. Firstly, the pyrolysis behavior of waste electronic plastics, such as pyrolysis mechanism and pyrolysis products, is introduced. Secondly, the migration and transformation process of brominated flame retardants during pyrolysis and its mechanism are introduced in detail. Then, the research progress on the emission, transformation and distribution of brominated pollutants during the pyrolysis of electronic plastics is systematically reviewed. Finally, a recovery route is proposed to obtain high quality pyrolytic oil and reduce the emission of brominated pollutants by co-pyrolysis of waste electronic plastics and biomass containing brominated flame retardants, aiming at obtaining bromine-free oil for commercial application.