Chemical Engineering March 2019 - 14

Newsfront
Chemical Recycling Makes
Waste Plastic a Resource
With an eye toward a circular economy, technology developers are advancing a host of new
approaches to chemical recycling of post-use commodity plastics
IN BRIEF
PET UPCYCLING
MAKING MIXED STREAMS
WORK
PLASTICS FROM
PYROLYSIS OILS
COORDINATED EFFORTS
IN PLASTICS RECYCLING
P
lastics are indispensable parts of almost
every sector of the economy,
with wide-ranging economic, environmental
and convenience benefits
in their use stage. But increasingly, the sheer
volume of plastics produced (estimated at
well over 300 million metric tons annually)
presents environmental risks if the material is
not captured, and represents a waste of resources
if the material is disposed of in landfills.
Currently, only a small fraction of commodity
plastics are recycled globally (some
estimates peg the number at 14%), while the
majority end up in landfills, incinerators or in
the environment, particularly the ocean.
The past two years have seen an acceleration
and expansion of efforts aimed at
addressing the issues associated with waste
plastic. Stakeholders from several industries
and from along the plastic value chain are
involved in a host of plastic-waste initiatives
(see box, p. 18). One aspect of the overall
effort is to foster the idea that plastic waste
can be a resource and that even single-use
plastics have value after they are discarded.
Jeff Wooster, global sustainability director
with Dow Packaging and Specialty Plastics
(Midland, Mich.; www.dow.com), says " We
are operating in a resource-constrained
world, so we need to keep driving toward
a circular economy. If plastics are landfilled,
we lose their value. We put energy and resources
into making those materials, and
that is lost if we landfill the waste plastic. Recycling
and energy recovery can retain the
value of those materials for society. "
14
The majority of plastic-recycling processes
today are mechanical, where waste thermoplastic
material from end-use products are
melted and used as a component of another
manufactured product. While improvements
continue to be made in this area (for example,
in spectral identification and sorting
of plastic items), it is clear that mechanical
recycling processes alone are not sufficient
to handle the volume of plastic recycling that
is required to shift society toward a circular
economy with regard to plastic.
" Making meaningful progress on the problems
we are facing related to plastic waste
will take a truly global effort - it needs to be
'all hands on deck,' " says John Thayer, head
of polyethylene business at NOVA Chemicals
(Calgary, Canada, www.novachem.com).
The limitations of existing recycling processes
and the push toward circular economy
ideals has driven development of chemical
recycling processes - those in which
polymers are taken back to their monomers.
This class of processes need to be developed
and deployed at scale to complement
existing mechanical recycling efforts. " Plastics
are too valuable of a resource to end up
as litter or trash, " NOVA's Thayer comments.
" One hundred percent of plastics should be
reused, recycled or recovered and regenerated.
We believe that chemical monomer recovery
is the best long-term solution, where
end-of-life plastics become feedstock that is
chemically indistinguishable from fossil-fuelsourced
monomer. "
Presented here are several advancements
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
MARCH 2019
http://www.novachem.com http://www.dow.com http://WWW.CHEMENGONLINE.COM
Chemical Engineering March 2019

Table of Contents for the Digital Edition of Chemical Engineering March 2019
