Thermal degradation of acrylonitrile-butadiene-styrene (ABS) containing flame retardants using a fluidized bed reactor: The effects of Ca-based additives on halogen removal

In this study, the thermal degradation of a waste fraction of acrylonitrile-butadiene-styrene containing brominated flame retardants was performed to reduce halogen content in the pyrolysis oil. Thermal degradation was completed using Ca-based additives (calcium oxide, calcium hydroxide and oyster shells) in a bench-scale pyrolysis plant equipped with a fluidized bed reactor and char separation system. Pyrolysis was carried out in a temperature range of 430-510 degrees C. In the absence of any additive, the oil yield amounted to about 77 wt.%. With the additives, the oil yield was markedly reduced to within a range of 45-64 wt.%. The principle compounds in the oils were toluene, ethylbenzene, styrene, cumene, a-methylstyrene, phenol and heteroatom-containing compounds. When Ca(OH)(2) was applied, total bromine and chlorine contents in the oil decreased to 0.05 and 0.04 wt.%, respectively. In addition, Ca(OH)(2) reduced the antimony content in the oil to below 0.001 ppm. Most of the halogens and antimony in the feed material were present in the char obtained after pyrolysis. (C) 2012 Elsevier B.V. All rights reserved.