Table 3.
| Polymer | Thermal decomposition mode | Reactor type | Pyrolysis process parameters |
Product yield |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Temp. (°C) | Heating rate (°C/min) | Pressure | Duration (min) | Gas (wt%) | Liquid (wt%) | Solid (wt%) | ||||
| PET | Fixed bed | 500 | 10 | -- | -- | 76.9 | 23.1 | 0 | ||
| -- | 500 | 6 | 1 atm | -- | 52.13 | 38.89 | 8.98 | |||
| PE | HDPE | Random chain lysis (fragmentation along polymer chain length resulting in monomers and oligomers) | Horizontal steel | 350 | 20 | -- | 30 | 17.24 | 80.88 | 1.88 |
| Batch | 450 | -- | -- | 60 | 5.8 | 74.5 | 19.7 | |||
| Semi-batch | 400 | 7 | 1 atm | -- | 16 | 82 | 2 | |||
| 450 | 25 | 1 atm | -- | 4.1 | 91.2 | 4.7 | ||||
| Fluidized bed | 500 | -- | -- | 60 | 10 | 85 | 5 | |||
| 650 | -- | -- | 20–25 | 31.5 | 68.5 | 0 | ||||
| LDPE | Batch | 430 | 3 | -- | -- | 8.2 | 75.6 | 7.5 | ||
| 500 | 6 | 1 atm | -- | 19.43 | 80.41 | 0.16 | ||||
| 550 | 5 | -- | -- | 14.6 | 93.1 | 0 | ||||
| Pressurized batch | 425 | 10 | 0.8–4.3 MPa | 60 | 10 | 89.5 | 0.5 | |||
| Fixed bed | 500 | 10 | -- | 20 | 5 | 95 | 0 | |||
| Fluidized bed | 600 | -- | 1 atm | -- | 24.2 | 51 | 0 | |||
| PVC | Chain-stripping (side chain reactions of substituents eliminating reactive substitutes (HCl), dehydrogenation and cyclization) | Vacuum batch | 520 | 10 | 2 kPa | -- | 0.34 | 12.79 | 28.13 | |
| Fixed bed | 500 | 10 | -- | -- | 87.7 | 12.3 | 0 | |||
| PP | Random chain fragmentation | Horizontal steel | 300 | 20 | -- | 30 | 28.84 | 69.82 | 1.34 | |
| Batch | 380 | 3 | 1 atm | -- | 6.6 | 80.1 | 13.3 | |||
| 740 | -- | -- | -- | 49.6 | 48.8 | 1.6 | ||||
| Semi-batch | 400 | 7 | 1 atm | -- | 13 | 85 | 2 | |||
| 450 | 25 | 1 atm | -- | 4.1 | 92.3 | 3.6 | ||||
| 500 | 6 | 1 atm | -- | 17.76 | 82.12 | 0.12 | ||||
| PS | Combination of chain rupture and unzipping, formation of oligomers | Batch | 500 | -- | -- | 150 | 3.27 | 96.73 | 0 | |
| 581 | -- | -- | -- | 9.9 | 89.5 | 0.6 | ||||
| Semi-batch | 400 | 7 | 1 atm | -- | 6 | 90 | 4 | |||
| Pressurized batch | 425 | 10 | 0.31–1.6 MPa | 60 | 2.50 | 97 | 0.5 | |||