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7/23/2019 Polyethylene Terephthalate.pdf
http://slidepdf.com/reader/full/polyethylene-terephthalatepdf 1/18
The Recycling of
Polyethylene Terephthalate
Michelle Chong
Grace Kim
Cluster 8COSMOS 2007
7/23/2019 Polyethylene Terephthalate.pdf
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Problem: MSW rate
• The amount of municipal solid waste (MSW) produced in
2005 was 245 million tons. – 4.5 pounds of trash per person per day
( h t t p: / / www. e p a. g ov / m s w / f a c t s .h t m )
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Our Subject
• The recycling of polyethylene terephthalate
(PET), which is common in textiles and plastic
drink bottles.
– Recycled PET can be used for the same purposes
• PET should be recycled because it is not
biodegradable
• there are four main ways to recycle PET:
– Primary
– Mechanical
– Chemical
– Energy recovery
C o ur t e s y of
h t t p: / / www. ak m ar k e t . c om
Courtesy of http://www.cotton.or Courtesy of
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Recyclable Plastics
• Six classifications of
plastics, each assigneda number:
– 1. Polyethylene
Terephthalate – 2. High-density
Polyethylene
– 3. Polyvinyl Chloride
– 4. Low-density
Polyethylene
– 5. Polypropylene
– 6. Polystyrene
http://eng.amipak.by/i/photo/page/
production/peffilm/ttt-018-big.jpg
Courtesy of
http://www.airseacontainers.com
http://www.flamar.it/images/tondi3.jpg
Courtesy of http://www.bayouplastics.com
http://www.path.cam.ac.uk/images/recycling/poly-chippings.gif
Courtesy of http://www.a-plastic-
bag.com
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Primary Recycling
• Deals with uncontaminated, clean PET
• It is popular and inexpensive• There is a limited amount of PET available
• Product can be mixed with pure PET or used as second-grade
material
(6)
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Mechanical Recycling
• Contamination removal
– PET is sorted, ground intoflakes, and washed with
detergent or a solvent
– Flakes are dried thoroughlyto prevent water from
ruining the product
• Product
– Flakes are melted and
extruded
– Possibly cross-linked to
enhance properties Courtesy http://www.made-in-china.com
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Chemical Recycling
• Hydrolysis
– PET is depolymerized toterephthalic acid (TPA) and
ethylene glycol (EG) by water in
an acid, alkaline, or neutralenvironment
– Requires high temperatures and
pressures and takes a long time;
costly
•Methanolysis
– Methanol depolymerizes PETto dimethyl terephthalate
(DMT) and EG
– High pressures and
temperatures
– DMT can be collected and
used as a monomer to produce
new PET
(6)
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Chemical Recycling ctd.
• Glycolysis
– EG is the reagent which partially depolymerizes PET intooligomers
– The process produces bis(hydroxyethyl) terephthalate
(BHET) – BHET is a substrate for the polymerization of PET
• It can be collected and used to create new PET
(6)
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Recycling by Energy Recovery
• Energy is recovered from PET by
incineration – Process carried out in special
chambers in waste-to-energy facilities
• PET has a very high stored energy
value
• There are 114 plants producing
energy to power 1.2 million homes
and businesses
• There is a concern that incineration
releases toxic substances into the
air and is a hazard.
Courtesy http://www.eia.doe.gov
C o ur t e s y o
f Wi k i p e d i a
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Plastic Factories
• The first PET bottle was recycled in 1977.
• Generally, plastic bottles factories manufacturers
prefer to use new resin rather than recycled
because it is cheaper.
www.formedfiber.com
www.selectdirect.us
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PET (polyethylene terephthalate)
• 95% plastic bottles are made from either PET or HDPE
• PET makes up about 48% of all plastics
• The recycling rates for plastic bottles however only
remain at 25%.• The plastics that are not recycled will stay in
landfills FOR V R and never degrade.
www.townsville.qld.gov.au
www.packworld.com
w w w . v
a n c e c o u n t y . c o m
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PET Recycling
• 167 million pounds of PET bottles were recycled last year….
But 271 million pounds still ended up going to waste.• In the United States alone, there are over 20,000 plastic
recycling programs; 10,000 of them are only for PET bottles.
• In 1996, 130 million cubic yards was conserved fromlandfills, and by 2005 it had increased to about 195 millioncubic yards.
www.rirrc.org
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Reduce, Reuse, Recycle
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Did You Know?
• Patagonia, Global Green, E-Wear,
Deja Shoe, Wickers and Reebok
are companies that use recycled
PET plastic in their products.
• Carpet is also made from PET plastic becauseit is sturdier than most nylon.
• The bumpers produced by Ford Motor
Company are made from millions ofpounds of PET plastic.
http://www.ci.keene.nh.us/publicworks/recycle/wearasodabottle.htmlwww.carpetandcanefur niture.co.uk
www.keilautogroup.com
www.myairshoes.com
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Biodegradable Plastics
• Though biodegradable plastics have been
around for a long time, the high expensehas never made it appealing.
• The reasoning behind non-degradableplastics is because “their long polymermolecules are too large and too tightly
bonded together to be brokenapart and assimilated bydecomposer organisms.”
Polyethylene Terephthalate
Gauss View
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Biodegradable Plastics ctd.
• Starch, a natural polymer produced from corn, wheat or
potatoes can be used in plastics because it contains themolecular structure that can be broken down bymicroorganisms.
• Due the fact that starch is soluble in water, it is first convertedinto lactic acid. The polymer, polylactide, is used in plastics.
• The price of biodegradable plastics being 2- 10 times moreexpensive than PET bottles, it is not very favorable in currentmarkets.
commons.wikimedia.org
Lactic Acid Courtesy of:
news.softpedia.com
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Credits
• Awaja, Firas, and Dumitru Pavel. "Recycling of PET." European PolymerJournal 41.7(2005): 1453-1477.
• Lotfi, Ahmad. "Plastic Recycling." 25 July 2007<http://www.lotfi.net/recycle/plastic.html>.
• "Municipal Solid Waste." 1 June 2007. U.S. Environmental Protection Agency. 25 July 2007 <http://www.epa.gov/msw/facts.htm>.
• "Plastics." 11 May 2006. U.S. Environmental Protection Agency. 27 July 2007<http://www.epa.gov/msw/plastic.htm>.
• Karayannidis, George P., and Dimitris S. Achilias. "Chemical Recycling ofPoly(Ethylene Terephthalate)." Macromolecular Materials and Engineering
292.2 (2007): 128-146.
• Subramian, P.M. "Plastics recycling and waste management in the US."Resources, Conservation, and Recycling 28(2000): 253-263.
• http://www.scdhec.gov/eqc/outreach/pubs/9-12_37.pdf
• http://www.container-recycling.org/mediafold/newsrelease/plastic/2006-12-8-PlasticBottleRecy.htm
• http://www.ci.keene.nh.us/publicworks/recycle/wearasodabottle.html
• http://www.napcor.com/funfacts.htm
• http://www.scdhec.gov/eqc/outreach/pubs/9-12_37.pdf
• http://biodegradableplastics.bio-tec.biz/
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Acknowledgements
Professor Patten Professor Allen
Professor Tantillo Mr. RaymondTA Eric TA Mike TA Slava
For all the help you’ve given ……
From: Grace &MichelleAND OF COURSE…….RA Mike & Kelsey
C o ur t e s y of S anr i o
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