Sustainable Plastics - May/June 2022 - 26

inside at... Agilyx
Plastic waste as feedstock.
Understanding the
science is key
O
continued from page 25
mally done by using solvents.
We are therefore able, for example,
to depolymerise polystyrene
very gently into styrene
monomer, or convert very distressed
plastic at full blast using
high heat and pressure, into pyrolysis
oil. This gives our technology
a flexibility and robustness
that others don't have. "
Agilyx, he emphasised, can
handle the heterogeneity that
characterises waste, including
foam, rigid plastics, multilayered
packaging, labels, PVC
or any other plastic others are
unable to process. " That's very
unique from a technology point
of view, " he pointed out.
Lastly, Agilyx truly focuses
on the technology, rather than
building plants - 'something
others can do far better', said
Larsen. The company relies on
a licensing model 'to enable its
partners, making plastics a circular
resource; that's the name
of the game'.
And where does this leave
mechanical recycling?
Mechanical recycling and
chemical recycling are 'very,
very' complementary to one
another, according to Larsen.
Whatever is being mechanically
recycled today should carry on
doing so, he said, and if possible,
be expanded.
The type of waste addressed
by chemical recycling is of a
different order from the PET
beverage bottles, the HDPE
milk and detergent bottles and
other rigid packaging that is
currently being mechanically
recycled. " And this feedstock
should continue to be collected
and processed by mechanical
recyclers, " he stressed.
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May/June 2022
Yet there is also a different
kind of waste, highly contaminated
flexible food packaging,
multilayered structures, foams
and the like, which are not traditionally
mechanically recycled.
In these cases, chemical
recycling makes sense. Chemical
recycling can considerably
boost the range of waste plastics
able to be returned to the
materials cycle.
Chemical recycling offers
another benefit as well: applications
that are not yet attainable
with mechanical recycling
become possible with chemical
recycling, including food-contact
applications.
" These are not competing
technologies, " he said. " They go
hand in hand. "
And Cyclyx, he added, is also
for mechanical recycling. " If the
feedstock is very pure and can
be mechanically recycled, Cyclyx
will divert it to be mechanically
recycled. On the other
hand, dirty, distressed infeed
will be diverted to chemical recycling.
It is as simple as that. "
Looking ahead
Chemical recycling has huge
potential, but it is still a very
young industry. There are challenges
ahead that range from
scaling the technology and
becoming cost-competitive to
achieving a sustainable carbon
footprint. Processes are
currently being developed to
maximise the fractions of the
pyrolysis oil produced that are
suitable for plastic production.
But what is also needed is more
investment, said Larsen.
" Multibillions are spent on
going from oil to plastics, " he
ne problem with the hostility against advanced recycling
technologies is that this not always based
on an understanding of how the technology works.
Marco Castaldi, Ph.D., a professor in the chemical
engineering department at the City College of New York, recently
pointed this out in a letter to the editor published 25
March on Syracuse.com. The letter was a response to critics of
the technology, who had referred to it as 'burning' plastics - a
practice which had 'no place in climate-forward New York'.
As Castaldi pointed out, 'advanced recycling technologies focus
on hard-to-recycle plastics such as flexible pouches, films
and tubes, converting them back into their raw materials to be
used to make new plastics. This process allows plastics to be
recycled each time a product is disposed by the consumer.'
To call this 'burning' is completely incorrect, Castaldi wrote,
and it represents a clear misunderstanding of technologies
and thermodynamic principles.
" Typical advanced recycling technologies operate with no
oxygen or air to convert post-use plastics to a liquid or gaseous
state. Incineration destroys waste materials by burning,
without recovering energy or materials. This is entirely different
from advanced recycling.
" Advanced recycling technologies today are being deployed
by both large plastics companies and multiple entrepreneurial
enterprises to 'remake' once non-recyclable plastics. These
technologies will divert non-recycled plastics from landfills
and the environment.
" Advanced recycling enables the creation of new plastics
from used plastics, displacing the need to extract fossil feedstock.
Importantly, they operate like other manufacturing facilities,
subject to federal, state and local regulations. A recent
study found air emissions from a typical advanced recycling
facility to be roughly the same as familiar facilities such as hospitals,
universities and food manufacturers. "
He concluded by stating that 'innovative technologies need
time to mature and often are confused with existing ones [...]. It
is not helpful when mischaracterisations and poor understanding
are disseminated. As New York state considers how to recover
its non-recycled plastics, it would be sensible to listen
to scientists and engineers who understand advanced plastics
recycling technologies.'
pointed out. " But when we look
at plastics to oil, we are talking
about millions. This is a mismatch
that needs to change.
We need to start getting these
recycling plants built, steel on
the ground. "
That said, the industry deserves
credit for trying to do
something about the problem of
plastics at the end of life, instead
of simply resigning itself to the inevitable
and continuing to landfill
and incinerate plastic waste. " We
should be recognised for trying
to do something about the problem, "
he said.
" I see, in time, our company
having proven that our technology
can be scaled in polystyrene,
in PMMA and in mixed
waste plastics. And to have
enabled people to recycle their
plastics so that we, as consumers,
can have the benefit of using
plastic without the worry of
where it will end up. That we will
have scaled the technology, sold
a number of licenses and really
enabled a circular economy.
" I may be a bit optimistic here,
but looking at the pipeline of
projects we have and the projects
moving through that pipeline
that are actually entering
the construction phase, I think
I am right to be. And hopefully,
there will be more to follow. "
http://www.Syracuse.com
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