factsheet plastic 2002

8/6/2019 Factsheet Plastic 2002

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PLASTICS

This document is a copy from the Warmer Bulletin Information Sheet.

History may view plastics asone of the most important

technical developments of the20th century. Plastics haveopened the way for newinventions and have replacedother materials in existingproducts. They are economic,light, durable and versatile,and resistant to moisture,chemicals and decay.

Yet these properties can alsobring problems. For example,if one believes that

degradability is a requiredcharacteristic of waste, thenplastics do not perform well(although neither do glass andmetal).

In view of the fact that landfillsproduce liquid and gaseousemissions which can have areal environmental impact, itcould be said that the stabilityof plastics is no realdisadvantage.

Almost 100 million tonnes pa(Mtpa) of plastics areproduced today.

Definition

The term plastic describes avast range of materials andcorn- pounds. There are about50 different families andhundreds of varieties.

Most plastics are made fromsimple hydrocarbon molecules(monomers) derived from oil orgas; biomass is anotherpossible source of rawmaterials, but it is still tooexpensive for most plasticsapplications. These undergo apolymerisationprocessto formmore complex polymers.Additives are used to give the

Types

There are two main types ofplastics; thermoplastics andthermosets.

Thermoplasticssoften whenheated and harden on cooling.

More than 80 per cent ofplastics are thermoplastics,examples of which include:o high density polyethylene

(HDPE) - used for bottlesfor detergents, foodproducts and toys

o low density polyethylene(LDPE) - for productssuch as ding-film, binliners and flexible con-tainers

o polyethylene

terephthalate(PET) -used in bottles, carpets &food packaging

o polypropylene (PP) usedin yoghurt and margarinepots, automotive parts,fibres, milk crates

o poly vinyl chloride(PVC) -is made from oil and saltand is used for windowframes, flooring,wallpaper, bottles,medical products

Thermosetsare hardened by acuring process and cannot bere-melted or re-moulded.

Examples of thermosets(which comprise 20 per cent ofall plastics), include:polyurethane(PU) - used incoatings, finishes, mattressesand vehicle seating, buildinginsulationepoxy -adhesives, boats,

sporting equipment, electricaland automotive componentsphenolics -used in ovens, andcircuit boardsunsaturated polyesters -windmills, car body parts,boats

Bio-plasticsMore recently plastics havebeen developed from plantmaterials and bacteria, socalled bio-plastics, which are

degradable. There are threetechniques used to producebio-plastics:o converting plant sugars

into plastic

o producing plastics insidemicro-organisms

o growing plastics in cornand other crops

About 8,000 tonnes polyactidethis process corn is milled toextract starch which is thenfermented to produce lacticpolymerised to produce PLA.Polyvinyl alcohol, potatostarch- based plastics,cellophane and ters are alsopart of the biode- gradablepolymers family.

The European market forbiodegradable plastics is per-haps 30 - 50,000 tonnes pa(tpa), depending ondefinitions.

Manufacture

Plastics consume four per centof the worlds oil stock asfeedstock. In Western Europe,consumption of plastics

reached 33.6 Mt in 1999.

However, in many applicationsthe use of plastics saves moreoil than is used for theirmanufacture. For example, ininsulating to make the foam issaved through reduced lossesin the first year. Also, thecarbon dioxide (CO2)reduction in the first year is 2-5times higher than the CO2emissions from the production

process. In the case ofpackaging, plastics have arelatively low energyrequirement compared toother materials; they alsoincrease the useful load pervehicle, and so reduce traffic,and the corresponding fuelconsumption and emissions.

UseMore than one third (40percent) of plastics are used in

packaging, wrapping almost50 per cent of all packagedgoods. One quarter of plasticsare used in the constructionindustry.


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Plastics consumption by industry sector

(Western Europe 1999)

Packaging

40%

Building & construction

18%

Electrical &

electronic

7.5%

Agriculture

2.5%

Other household

19%

Automotive8%

Large

industry

5%

Total 33.6 Mt (1999)

Other major uses are inelectronic goods ore vehicles,medical and healthapplications, informationtechnology andcommunications.

Sources of waste plastics

PackagingPackaging is the main sourceof waste plastics (60 per cent).Approximately 65 per cent ofplastic packaging waste inWestern Europe is fromhouseholds, the rest comesfrom commerce and industry.In 1999, 13.4 Mt (40 per cent

of the total) were used forpackaging. About 50 per centof all Europes goos are nowpackaged in plastic, but byweight these only account for17 per cent pf all packaging .Six types of plastics accountfor virtually all of thepackaging used.

The most ubiquitous ispolyethylene (56 per cent byweight); others are PP, PVC,PS, and PET.

Building and constructionThis is the second largestsector, consuming 18 per cent

of plastics or 6.2 Mt in 1999.PVC is the main plastic usedin building and constructionsector.

About half of the plastics used

in buildings are for pipes andducts, 30 per cent forinsulation and the rest forwindows and floor coverings.PVD is the most commonplastic used in the constructionindustry. About 0.47 MT ofplastics were disposed of bythe building and constructionindustry in Western Europe in1999.

Electrical and Electronic

Many of the newcommunications technologiesbeing developed use the latesttypes of plastic and arisings inthis sector are expected toincrease rapidly. While thenumber of applicationscontinues to increase, theweight of the plastic used ineach unit tends to decrease.

Cable insulation accounts forthe larges use of plastic in theelectronic sector at 41 percent. In 1999 some 2.5 Mt ofplastic were used in this sector(mainly PVC andpolyethylene), while 0.76 Mt

plastics waste were produced virtually all of which (96 percent) were disposed of tolandfill or incineration.

Agriculture

Farm plastics from horticultureand livestock activities isusually contaminated with soiland is expensive to remove.This is not a controlled wastestream and items are usuallyburied or burnt on the farm. In1998, 92,000 t plastics wereproduced on UK farms. Onethird of this was plasticpackaging, mostly PE and PP.

Across Europe, agricultural

plastics accounted for only 2.5per cent (0.85 Mt) of the total.Waste plastics fro this sectoramounted to 0.27 Mt in 1999,of which more than one third(38 percent) was recycled.

AutomotiveIn 1999, 1.8 million vehicleswere scrapped in the UK;plastics make up nearly tenper cent of materials in cars.Only three per cent of theseplastics were recycled, mostlythe polypropylene casingsfrom batteries. The use of PPin care interiors is expected toincrease in the future.


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European legislation on end oflife vehicles requires that 95percent by weight of carsshould be re-used orrecovered by 2015 andplastics recycling will need toincrease to meet this target.

Environmental impacts

Making plastics has a range ofimpacts on the environment.Manufacturing requiressignificant quantities of fossilfuels. Many chemicals areused, and air emissions,water, and waste aregenerated. Transport of rawmaterials and productdistribution also have

environmental impacts.

The manufacturer of polymersinvolves large volumes ofpotentially harmful chemicals.Those causing environmentalconcern include volatileorganics compounds, some ofwhich (e.g. benzene) are toxic.However, the polymerisationshare in EU VOC emissions isnow less than 0.5 per cent ofthe total

Wastes arising

Despite the huge demand forplastics across all sectors,they account for less than oneper cent of the total waste byweight. In Western Europe in1999, some 2/73 Mt of wasteswere produced, of which 19 Mt

(0.7 per cent) were post-userplastics.

Plastics waste managementand resource recovery

In 1999 32 per cent of waste

plastics in Western Europewere recycled (2.1 Mt) orunderwent energy recovery(4.0 Mt), the remainder (13.6Mt) being landfilled.

In the US, more than 80 percent of the population, nearlytwo hundred million people,have access to plasticsrecycling collection facilities. In1999 more than 750/000 tonsof plastic bottles were

recycled; the overall recyclingrate for plastics has stabilisedat around 23 per cent.

There are more than 1,300plastic products with recycledcontent on the Americanmarket.

Mechanical recyclingThis is the plastics industry'spreferred method of recyclingfor those fractions that are

mono-material relatively cleanand of reliable availability.

In 1999/1.8 Mt (9.4 per cent)of used plastic were recoveredthrough mechanical recyclingin Europe. Germany leads theway, recycling 18 per cent ofits total plastics waste in 1999.

Mechanical recycling ofplastics has the greatestenvironmental benefit if therecyclate is used to substitutevirgin polymer, irrespective ofthe collection method(kerbside or bring-bank)

However, the contaminationlevel heavily depends on theway the collection scheme isdesigned. Feedstock recyclinghas similar environmentalbenefits to clean and relativelyefficient energy recovery, but itis relatively costly.

Modern energy recovery unitscan score better from anenvironmental standpoint thanmechanical or feedstock

recycling. In any case energyrecovery of waste plastics inmodem plants has benefitsover landfill. Diversion fromlandfill is the most importantfactor influencing the eco-efficiency of plastics wasterecovery.

In the last ten years theplastics industry in NorthAmerica invested more thanUS$lbillion in recycling

initiatives and demand forrecycled plastics in productshas grown. Examples of theseproducts are fleece clothing,packaging applications,playground equipment andgarden products.

Total post-user plastics waste by sector (Western Europe,

1999, per cent by wt)

Municipal solid waste

(MSW) 67%

Agriculture

1% Automotive

4%

Distribution

& industry

21%

Building &

construction

3%

Total 19.1 Mt (1999)


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North American consumershave given strong support tooutdoor furniture made fromrecycled plastics. In 1998more than 0.32 Mt PET and0.34 Mt HDPE bottles wererecycled in North America and

there is capacity in theindustry to recycle another0.20 Mt of PET and 0.30 MtHDPE.

Feedstock recyclingFeedstock recycling convertsplastics waste back to basicraw materials (syncrude) foruse as secondary feedstock inrefineries, petrochemicalplants and chemical reactors.Or as monomers for the

production ofnew plastics(PMMA/ nylon 6, PET are de-polymerised to producemonomers which re-enter thepolymerisation loop)

There are other processes,such as gasification, whichuse the synthetic gasproduced either insituas areducing agent in blast furnacesteel production or as -awmaterial for methanol and

subsequently new polymerpolyacetal) production.

Pyrolysis is also an option.This involves heating plasticsin the absence of oxygen tobreak iown the long polymerchain into small molecules,

energy recoveryPlastics have a high energycontent or calorific value,which an often usefully be

recovered. some cement kilnsuse waste elastics as a sourceof fuel.

There has been concern overhe incineration of someplastics, especially PVC, withregard to the production ofdioxins. These are persistentorganic substances that havepossible toxic andcarcinogenic effects and arebio-accumulators.

In MSW incineration, thepresence of chlorine (in egPVC) an lead to dioxinproduction. however, dioxin

emissions from municipalwaste incinerators fell by morethan 98 per cent between1990 and 1997, and are nowresponsible for about three percent of total dioxin emissionsin the UK. The quantity of

dioxins produced is now solow that there is no correlationbetween emissions andchlorine content of theinput.The main parameters are thedesign of the incinerator andthe operational conditions.Chlorine is present in excessfor the dioxin reaction, due tosalt in food, residues, paper,plants and vegetables etc.Advanced thermal processing

Conclusions

Worldwide, policies are beingintroduced that demandrecycling, diversion fromlandfill of untreated wastesand greater levels of resourceconservation. This is beingachieved through thedevelopment of local, nationaland international strategies,new regulations setting targetsand economic, market- based

instruments and taxes.

It is clear that the use ofplastics reduces the mass ofmaterials needed in manyapplications and manysectors. However, the morenumerous, specialised.engineered and differentiatedbecome plastics materials, theless interesting it becomes torecycle them mechanically.Other recovery options most

often lead to higherenvironmental benefits, atlower costs.

A broadly agreed hierarchy ofwaste management objectivesplaces waste minimisation andprevention ahead of all thealternatives.

The plastics industry hasprobably already contributedmore to this aspiration than

others through product design,reduced material and energyuse.

A blend of mechanical and

feedstock recycling to createsecondary raw material wheresensible and recoveringenergy efficiently whereappropriate, is likely to offerthe best route to managingwaste plastics eco-efficiently.

Residua May, 2003

Warmer Bulletin is publishedby Residua, a companyformed to provide world-wideinformation on sustainablemanagement of municipalsolid waste.

Titles in this series of Informationsheets include:Advanced thermal processingAluminium making & recycling

BatteriesCarpetsCartonsCompostComposting with wormsConstruction & demolition wastesElectrical & electronic wastesEnergy from wasteGlass re-use & recyclingHealthcare wastesHousehold hazardous wasteIntegrated waste managementLife cycle assessment (LCA)Materials recovery facilities

NappiesPackagingPaper making & recyclingPlasticsRe-useSteel making & recyclingTextilesTyresVehicle recyclingWaste minimisationZero waste

Single copies of these informationsheets are available free ofcharge to Warmer Bulletinsubscribers, who can also collectcopies from the Internet(www.residua.com).

Additional copies may bepurchased at 1 each.

Further details available from:Residua1

stfloor

The British SchoolSkiptonNorth Yorkshire, BD231EP/ UK

Tel: (Int+44) (0)1756 709 800Fax: (Int+44) (0)1756 709801

Email: [email protected]: www. Residua.com

factsheet plastic 2002

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