The
carbon
intensity
(CI)
of
producing
five
different
resins
–
polyethylene
terephthalate
(PET),
high-density
(HDPE),
low-density
(LDPE),
polypropylene
(PP),
and
polyvinyl
chloride
(PVC)
in
four
international
regions
United
States
America
(USA),
Western
Europe,
Middle
East
Northern
Africa
(MENA),
China
is
calculated
on
a
cradle-to-gate
basis
using
the
Greenhouse
Gases,
Regulated
Emissions,
Energy
Use
Transportation
(GREET)
model.
list
factors
that
can
potentially
vary
CI
include
electricity
natural
gas
(NG)
production,
steam
cracking
feedstock
mix,
propylene
sourcing
technology
terephthalic
monomer
(TM)
use
hydrogen
co-product
from
process,
vinyl
(VCM)
production
mix.
Chemical Reviews,
Год журнала:
2024,
Номер
124(5), С. 2617 - 2650
Опубликована: Фев. 22, 2024
The
societal
importance
of
plastics
contrasts
with
the
carelessness
which
they
are
disposed.
Their
superlative
properties
lead
to
economic
and
environmental
efficiency,
but
linearity
puts
climate,
human
health,
global
ecosystems
at
risk.
Recycling
is
fundamental
transitioning
this
linear
model
into
a
more
sustainable,
circular
economy.
Among
recycling
technologies,
chemical
depolymerization
offers
route
virgin
quality
recycled
plastics,
especially
when
valorizing
complex
waste
streams
poorly
served
by
mechanical
methods.
However,
exists
in
interlinked
system
end-of-life
fates,
complementarity
each
approach
key
environmental,
economic,
sustainability.
This
review
explores
recent
progress
made
five
commercial
polymers:
poly(ethylene
terephthalate),
polycarbonates,
polyamides,
aliphatic
polyesters,
polyurethanes.
Attention
paid
not
only
catalytic
technologies
used
enhance
efficiencies
also
interrelationship
other
systemic
constraints
imposed
Novel
polymers,
designed
for
depolymerization,
concisely
reviewed
terms
their
underlying
chemistry
potential
integration
current
plastic
systems.
Polymer Engineering and Science,
Год журнала:
2023,
Номер
63(9), С. 2651 - 2674
Опубликована: Июнь 21, 2023
Abstract
Polyethylene
terephthalate
(PET)
is
used
in
textile
and
packaging
industries.
The
main
source
of
PET
production
fossil
fuels
with
limited
capacity.
Also,
products
are
single
use
that
transform
into
high
volumes
wastes,
causing
ecosystem
problems.
Recycling
proposed
to
confront
this
challenge.
four
major
recycling
techniques
mechanical,
chemical,
pyrolysis,
enzymatic.
Mechanical,
enzymatic
have
constrained
capabilities
manage
waste.
Chemical
the
potential
path
expanding
waste
possibility
upcycling
addressing
dirty
streams.
Several
chemical
methods
introduced
discussed
literature.
five
glycolysis,
alcoholysis,
aminolysis,
ammonolysis,
hydrolysis.
This
review
describes
depolymerization
via
these
introduces
hydrolysis
as
one
can
depolymerize
an
organic‐free
solvent
environment.
Hydrolysis
tolerates
mixed
wastes
streams
including
copolymers.
It
helps
avoid
challenges
attributed
using
organic
solvents
reaction
systems.
Moreover,
produces
terephthalic
acid,
monomer,
which
has
recently
gained
attention
initiative
monomer
for
production.
focuses
on
three
forms
hydrolysis—alkaline,
neutral,
by
presenting
background
studies,
issued
patents,
recent
trends
application
One Earth,
Год журнала:
2024,
Номер
7(3), С. 520 - 531
Опубликована: Март 1, 2024
In
2019,
the
United
States
consumed
over
57
million
metric
tons
(MMT)
of
plastic
with
less
than
7%
recovered
for
reuse.
This
study
provides
an
updated
material
flow
analysis
at
national
and
regional
scales
all
durable
single-use
plastics
in
States.
From
this
analysis,
we
develop
a
series
alternative
future
scenarios
that
envision
scale-up
recycling
technologies,
incorporating
technical
limitations
sorting
infrastructure
constraints.
The
results
suggest
maximum
68%
(24
MMT)
waste
could
be
diverted
from
landfills
by
scaling
up
existing
commercial
technologies.
Based
on
current
technological
landscape,
reaching
near-zero
is
only
possible
if
processes
are
operating
pilot
laboratory
can
effectively
scaled
coupled
improved
infrastructure.
Through
these
increased
recycling,
availability
postconsumer
resin
stocks
increase
22–43
MMT.
Abstract
Poly(ethylene
terephthalate)
(PET),
extensively
employed
in
bottles,
film,
and
fiber
manufacture,
has
generated
persistent
environmental
contamination
due
to
its
non‐degradable
nature.
The
resolution
of
this
issue
requires
the
conversion
waste
PET
into
valuable
products,
often
achieved
through
depolymerization
monomers.
However,
laborious
purification
procedures
involved
extraction
monomers
pose
challenges
constraints
on
complete
utilization
PET.
Herein,
a
strategy
is
demonstrated
for
polymer‐to‐polymer
upcycling
high‐value
biodegradable
programmable
materials
named
PEXT.
This
process
involves
reversible
transesterifications
dependent
ester
bonds,
wherein
commercially
available
X‐monomers
from
aliphatic
diacids
diols
are
introduced,
utilizing
existing
industrial
equipment
utilization.
PEXT
features
molecular
structure,
delivering
tailored
mechanical,
thermal,
biodegradation
performance.
Notably,
exhibits
superior
mechanical
performance,
with
maximal
elongation
at
break
3419.2
%
toughness
270.79
MJ
m
−3
.
These
characteristics
make
suitable
numerous
applications,
including
shape‐memory
materials,
transparent
films,
fracture‐resistant
stretchable
components.
Significantly,
allows
closed‐loop
recycling
within
specific
analogs
by
reprograming
or
X‐monomers.
not
only
offers
cost‐effective
advantages
large‐scale
advanced
but
also
demonstrates
enormous
prospect
conservation.
Waste Management,
Год журнала:
2024,
Номер
186, С. 293 - 306
Опубликована: Июль 1, 2024
The
compositions
of
Dutch
lightweight
packaging
waste
(LWP)
and
sorted
products
named
"PET
(Polyethylene
terephthalate)
trays"
have
been
determined
on
object
level.
Additionally,
the
PET
trays
from
both
types
were
in
16
categories
representing
their
use
material
build-up.
composition
at
least
10
representative
each
category
was
with
chemical
thermal
analysis,
based
which
average
per
established.
Based
this
data
tray
approximated.
recyclability
various
assessed
most
ubiquitous
LWP
only
found
to
be
suitable
produce
opaque
recycled
mechanical
recycling
processes.
Whereas
some
more
uncommon
can
used
transparent
Depolymerisation
is
deemed
a
appropriate
process
that
will
allow
production
food-grade
PET.
Sustainable Chemistry,
Год журнала:
2023,
Номер
4(4), С. 363 - 393
Опубликована: Дек. 18, 2023
Poly(ethylene
terephthalate),
the
fifth
most
produced
polymer,
generates
significant
waste
annually.
This
increased
production
has
spurred
interest
in
chemical
and
mechanical
pathways
for
recycling.
The
shift
from
laboratory
settings
to
larger-scale
implementation
creates
opportunities
explore
value
recovery
of
recycling
products.
Derived
glycolysis
PET,
bis(2-hydroxyethyl)
terephthalate
(BHET)
exhibits
versatility
as
a
depolymerization
product
valuable
monomer.
BHET
finds
application
across
diverse
industries
such
resins,
coatings,
foams,
tissue
scaffolds.
Incorporating
BHET,
which
is
product,
supports
higher
rates
contributes
more
sustainable
approach
generating
materials.
review
illuminates
feedstock
circular
polymer
materials
economy.
