Performance analysis and fate of bromine in a single screw reactor for pyrolysis of waste electrical and electronic equipment (WEEE)

Abstract

This study focuses on chemical recycling of plastics from waste electrical and electronic equipment (WEEE), which constitutes a problematic waste fraction due to the presence of brominated flame retardants. An auger reactor has been designed and used for this study. Real WEEE material provided by Stena Technoworld has been pyrolyzed under different temperature conditions. The performance of the reactor as well as other important parameters such as the fate of the bromine have been investigated and evaluated. The main outcome of this investigation is to simulate a continuous process, which can be useful for designing a full-scale industrial process. The mass balance results after performing thermal treatment at 400, 500, and 600 °C, showed a high gas yield (44 %wt) at the temperature of 600 °C, which energy content is enough to self-sustain the auger reactor. At the low temperature of 400 °C the oil production reaches its maximum yield as well as maximum concentration of bromine, corresponding to 0.5 wt% in the oil. Several valuable organic compounds have been detected in the oil composition, which can be used as precursors for feedstock recycling producing new plastics.