The document discusses various types and properties of plastics, environmental issues caused by plastic waste, and different plastic waste management methods including recycling, conversion to solid or liquid fuels, and use of degradable plastics. It describes primary, secondary, tertiary, and quaternary recycling. Methods for sorting, processing, and recycling plastic waste are outlined, along with production of refuse derived fuel and conversion of plastics to gaseous and liquid fuels through pyrolysis or gasification. Co-processing plastic waste in cement kilns and plasma pyrolysis are also summarized.

1. VISHNU RAJ R
14CE63R09

2.  Plastics are synthetic polymers derived from petro-
fossil feedstock and made-up of long chain
hydrocarbons with additives
Two types of plastics
 Thermoplastics(Recyclable)-become soft when
heated, can be moulded or shaped with pressure when
in plastic state
 Thermosets (Non Recyclable)-Once set cannot be
remoulded /softened by applying heat.

4. Environmental Issues
 Plastic waste disposal on land makes it infertile
 Burning generates toxic emissions -CO, HCl, Dioxin,
Furans
 Leaching out of toxic chemicals added as additives
 Littering
 Affects waste processing facilities like composting
 In efficient usage of crude oil resources

5. Plastic Waste Management

6. Recycling of plastics
 Primary Recycling: involves processing of a waste
into a product with characteristics similar to those
of original product.
 Secondary (Mechanical)Recycling: processing of
waste plastics into products that have characteristics
dissimilar from those of original plastic products
 Tertiary(Chemical) Recycling: extraction of
chemicals from plastic wastes
 Quaternary Recycling: recovery of energy from
wastes

7. Sorting Of Plastic Wastes
 Density sorting
 Hydrocyclones- uses centrifugal force, enhance
material wettability.
 Heavy medium separation -using tetrabromoethane
 Triboelectric separation- sorts materials on the basis of
a surface charge transfer phenomenon
 Speed accelerators
Paint Removal
Grinding & Solvent stripping

8. Mechanical Recycling
Can only be performed on single-polymer plastic
Steps involved
 Crushing/Shredding
 Contaminant separation:
 Floatation
 Milling
 Washing and Drying
 Agglutination
 Extrusion

9. Mechanical recycling steps as described by Aznar et al. (2006).

10. Existing recycling processes & Issues
 Selection of waste:
Toxic wastes are separated
 Segregation of plastics waste: Segregation shall be
done in accordance with IS 14535
 Processing (extrusion process)
Washing generates waste water having high pollution load
& needs treatment before proper disposal
Exposure of workers in reprocessing plant to toxic dyes and
additives

11. CONVERTING WASTE INTO A
RESOURCE
quality concerns when converting waste plastics into fuel
resources are
 Smooth feeding to conversion equipment
 Effective conversion into fuel products
 Well-controlled combustion and clean flue gas in fuel
user facilities

12. plastics & fuel they produce

13. SOLID FUEL PRODUCTION
Two types of solid fuel
 refuse derived fuel (RDF)
 refuse-derived paper and plastic densified fuel (RPF)
o Thermoplastics act as a binder for the other
components
o Contamination of plastics with other plastics
containing halogens (Cl, Br, F), N, S and other
hazardous substances may cause air and soil pollution

14. Production method
Involves two steps- pretreatment and pellet production
Two types of commercial production systems
 large-scale model(3 ton/hour)with pretreatment for
the separation of undesirable contamination
 small-scale model (150 kg/hour) without pretreatment
equipment
Heating values
RDF: 4000 – 5000 kcal/kg
RPF: 6000 – 8000 kcal/kg

15. Schematic diagram of pretreatment process

16. Schematic diagram of a pelletizing process

17. Liquid Fuel Production
 Based on the pyrolysis of the plastics and the
condensation of the resulting hydrocarbons
 Thermoplastics (PE, PP, and PS)are used for
conversion.
 Decomposition occur at 450 to 550 °C.
 The products generated from include gasoline, diesel,
benzene, naphtha, and fuel oil
 The by-products from the process - sludge and gas are
reused.

18.  PVC plastics waste is not used as the chlorine can be
converted into HCl as a by-product
Schematic diagram of a liquid fuel production plant (UNEP, 2009)

19. Gaseous Fuel Production
 Waste plastics undergo thermal decomposition
in a tank reactor for an extended time at a reaction
temperature
 Occurs at higher temperatures 800 -1000 °C
 Two types of gaseous fuel are produced:
Gaseous hydrocarbon & Syngas
 Calorific value of syngas ranges between the calorific
value of biogas and LNG/LPG.

20. Gasification process for converting plastic wastes to chemicals (PCD, 2011)

22. Observations
 Impact, Los Angels Abrasion & Crushing Value
increased with the increase in the percentage of
plastics.
 Better skid resistance
 Unevenness index values were low (3000 mm/km)
indicating good surface evenness.
 Better resistance towards water stagnation i

23. Co-processing of Plastic waste in
Cement Kiln
 Plastic waste is used as an alternative fuel in cement Kilns
 Primary fuel and raw material are substituted by waste
Pre-processing of plastic waste
 Plastic waste is sun dried and subjected to shredding before
feeding into cement kilns
 PVC containing plastic waste is not used as it impair the cement
quality

24. Plasma Pyrolysis
 Disintegration of organic compounds into gases and
non leachable solid residues in an oxygen-starved
environment
 Uses ions and excited molecules with high energy
radiation to decompose chemicals
 High temperature decomposes waste material into
simple molecules

25.  Efficient way of treating chlorinated plastics
 Dioxins and furans emissions are below the prescribed
limits ie, the range of 0.005-0.009 ng/m3
 Ideal for decentralized disposal of plastic waste
 Reduction in volume of organic matter > 99%
 Segregation of the waste is not necessary

26. DEGRADABLE PLASTICS
Types
 Poly-Lactic Acid (PLA)
produced in a two-step fermentation and chemical
polymerization process
 Polyhydroxyalkanoate (PHA)
synthesized by bacteria as intracellular carbon and
energy storage compounds
 Poly olefins modified by adding transition
metals/compounds
 Oxo-biodegradable plastics

27.  Moisture and heat attack PLA polymer chains,
splitting them apart through hydrolysis, to lactic acid
monomers which are consumed by microbes
 PHA plastics are attacked by microorganisms that
secrete PHA depolymerizer, and most products take
three to nine months to degrade
 Polyolefins are decomposed by UV or heat-initiated
oxidation

28. Plastic degradation processes
 Photo degradation: Degradation caused through the
action of sunlight on the polymer
 Biodegradation :Degradation that occurs through the
action of microorganisms such as bacteria, yeast, fungi,
and algae etc.
 Biodeterioration: Degradation that occurs through the
action of microorganisms such as beetles, slugs, etc.
 Autooxidation :Degradation caused by chemical reactions
with oxygen.
 Hydrolysis: Degradation that occurs when water cleaves
the backbone of a polymer, resulting in a decrease in
molecular weight and a loss of physical properties
 Solubilization: Dissolution of polymers that occurs when
a water-soluble link is included in the polymer

29. Compatibility of Degradable Plastics
with Current SWM Practices
 Composting
Require specific levels of moisture and oxygen &
inadequate temperatures may not initiate the key
hydrolysis reaction for PLAs
 Recycling
The increase in input heterogeneity will reduce the quality
of the recovered plastic
 Waste-to-Energy Incineration
Less CO2 emissions
 Landfilling
Decay and release of more methane , production of higher
strength leachate & sequestration of carbon,

30. Drawbacks
 Higher costs
 Difficulty in recycling
concerns regarding potential later degradation of the
end products
 Requirement of specific levels of moisture and oxygen
for initial reactions to occur

31. References
 Recycling and recovery routes of plastic solid waste (PSW):
A review, S.M. Al- Salem , P.Lettieri, J. Baeyens
 Environmental evaluation of plastic waste management
scenarios: L. Rigamontia, M.Grossoa, J. Møllerb, V.
Martinez Sanchezb,S. Magnania, T.H. Christensen
 A Review of Plastic Waste Management Strategies:Javeriya
Siddiqui and Govind Pandey, International Research
Journal of Environment Sciences
 Development of process for disposal of plastic waste using
plasma pyrolysis technology and option for energy
recovery: M. Puncochara, B. Rujb, P. K. Chatterjee
 Degradable Plastics and Solid Waste Management Systems:
David J. Tonjes ,Krista L. Greene

32.  IS 14534 1998 -GUIDELINES FOR RECYCLING OF
PLASTICS
 Preliminary Study On The Conversion Of Different
Waste Plastics Into Fuel Oil : Yasabie Abatneh,
Omprakash Sahu
 Biodegradability of Plastics : Yutaka
Tokiwa, Buenaventurada P. Calabia ,Charles U.
Ugwu and Seiichi Aiba
 Recycling of plastic: accounting of greenhouse gases
and global warming contributions : Thomas Astrup,
Thilde Fruergaard, Thomas H. Christensen