Catalytic pyrolysis of flame retarded high impact polystyrene over various solid acid catalysts

The catalytic pyrolysis of flame retarded high impact polystyrene (Br-HIPS) was performed in the presence of five different solid acid catalysts in order to remove the bromine from the derived pyrolysis oil. The catalysts were three zeolite materials (HY, H beta and HZSM-5) and two mesoporous solids (all-silica MCM-41 and active Al2O3). The results showed that in the presence of HY and H beta zeolites, a reduction of approximate 50 wt.% in oil yield and a corresponding increase in wax and gas yields were obtained compared to thermal degradation. The addition of HZSM-5 showed less impact on product distribution and produced more oil compared with the other zeolites. The mesoporous catalyst of all-silica MCM-41 obtained the highest oil yield of 67.9 wt.% and reduced the wax yield to 8.73 wt.%. In terms of the composition of the pyrolysis oil, HZSM-5 and all-silica MCM-41 were favorable to produce more valuable single ring aromatics, such as toluene, ethylbenzene and cumene. Moreover, the catalysts exhibited pronounced debromination performance, especially the H beta catalyst, achieving the debromination efficiency of 70.47%. The results confirmed the catalytic pyrolysis of Br-HIPS and debromination performance was well related to the textural properties of catalysts. (C) 2016 Elsevier B.V. All rights reserved.