Environmental Engineering Reference
In-Depth Information
Table 9.6
Selected Examples of Thermolysis of Common Plastics
Yielding Monomer and Mixed Fuel Gas/liquids
Plastic resin
type
Approach
Product
Polystyrene (Woo
et al., 2000)
PS
MgO-catalyzed
thermal
depolymerization:
~350°C
Styrene ~ 93%
Polystyrene
(Lilac and Lee,
2001)
PS
Hydrolysis with
supercritical
H
2
O: ~382°C and
28 MPa
Styrene ~ 90%
Polycarbonate
(Huang et al.,
2006)
PC
Supercritical
ethanol solvolysis
Bisphenol A ~90,
diethylcarbonate ~89%
Poly(methyl
methacrylate)
PMMA Pyrolysis (in the
absence of air)
Methyl methacrylate
~90-98%
Mixed
polyolefins
(HDPE, LDPE,
PP) (Nishino et
al., 2005)
Pyrolysis
catalyzed by
Ga-ZSM-5 has
been reported
~50% liquid fraction,
predominantly benzene;
toluene and xylene; gas
fraction was mostly H
2
Polyethylene
(Horvat and Ng,
2005)
HDPE Pyrolysis under
N
2
at 400-440°C
~80-90% straight-chain
alkanes and 1-alkenes
Plastics such as polystyrene undergo facile-catalyzed thermal
depolymerization or pyrolysis yielding very high yields of styrene monomer.
Base-catalyzed depolymerization of the polymer is as follows.
