polyethylene terephthalate.pdf

7/23/2019 Polyethylene Terephthalate.pdf

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The Recycling of

Polyethylene Terephthalate

Michelle Chong

Grace Kim

Cluster 8COSMOS 2007



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 )



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



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



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)



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



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)



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)



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



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



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



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



Reduce, Reuse, Recycle



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

http://www.ci.keene.nh.us/publicworks/recycle/wearasodabottle.html





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



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



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/

http://www.scdhec.gov/eqc/outreach/pubs/9-12_37.pdf


http://biodegradableplastics.bio-tec.biz/

http://biodegradableplastics.bio-tec.biz/





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

polyethylene terephthalate.pdf

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