Plastic waste management- Conventional and New Technology
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Transcript of Plastic waste management- Conventional and New Technology
PLASTIC WASTE MANAGEMENT
DEPARTMENT OF CIVIL ENGINEERING S. V. NATIONAL INSTITUTE OF TECHNOLOGY
SURAT – 395007
RAMKESH MEENA (U13CE106)
PLASTIC
Plastic is a material consisting of any of a wide range of synthetic or semi-synthetic organic compounds that are malleable and can be molded into solid objects.
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CONSUMPTION OF PLASTIC
USA EUROPE CHINA INDIA BRAZIL0
20
40
60
80
100
120
109
65
45
9.7
32
Per capita plastic products consumption (Kg/person)
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HEAP OF GARABAGEACCORDING BMC MUMBAI ENVIRONMENTAL STUDIES
REPORT 2014-15
wood & cloth10, 10
plastic, glass & paper17, 17
grains & veg-etables, 73
wood & cloth10 plastic, glass & paper17 grains & vegetables
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CONSUMPTION OF PLASTIC
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CLASSIFICATION OF PLASTIC
1. THERMOPLASTIC
2. THERMOSETTING
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THERMOPLASTIC
Thermoplastics (Thermo=heat Plastic =A State Between Solid And Liquid) Are Made Of Long Chain Molecule That Are Entangled With Each Other But Not Bonded Together.
Thermoplastic Materials Can Be Cooled And Heated Several Times.
They Can Be Recycled.
When Thermoplastics Are Heated, They Melt To A Liquid. They Also Freeze To A Glassy State When
Cooled Enough.
Thermoplastic Can Be Moulded Into Any Shape.• Eg. Polyethylene• Polyvinyl Chloride (Pvc)• Nylon And Teflon• Polypropylene• Polystyrene
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THERMOSETTING
• Thermosetting Made From Long Chain Molecules Tied With Strong Covalent Bond And Cross Linked .This Cause Plastic Became Rigid And Not Flexible Even At High Temperature.
• They Are Better Suited To High-Temperature Applications Up To The Decomposition Temperature.
• They Are More Brittle.
• EXAMPLES--
PHENOLIC RESIN
AMINO AND EPOXY RESIN
BAKELITEPOLYURETHANEVULCANIZED RUBBER
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THERMOSETTING PLASTIC
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THERMOPLASTIC VS THERMOSETTING
Thermoplastic ThermosettingWhen heated become soften and melted and become hard on cooling ; process is reversible
Become hard on heating; process is irreversible
They Can be molded and remolded They can molded once and cannot remolded and reshaped
They are addition polymer They are condensation polymer
Structure is generally linear Structure is cross-linked
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PLASTIC WASTE
1. Polyethylene Terephthalate (PETE)
2. High-density Polyethylene (HDPE)
3. Polyvinyl Chloride (PVC)
4. Low-density Polyethylene (LDPE)
5. Polypropylene (PP)
6. Polystyrene (PS)
7. Others (Polycarbonate )
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RECYCLE CODE
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POLYETHYLENE TEREPHTHALATE(PP)
• Description: . It has become extremely popular for food and drink packaging purposes because of its strong ability to create a liquid and gas barrier - so oxygen cannot get in to spoil food, and the carbon dioxide that makes drinks fizzy cannot get out. Properties: clarity, lightness, strength, toughness, barrier to liquid and gas.
• Typical use: bottles (water, soft drink, juice, beer, wine, jam jars, detergent and cleaner containers,
• insulation for wire and insulating tapes,
• Used in guitars, pianos and vehicle/yacht interiors.
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POLYETHYLENE TEREPHTHALATE(PP)
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POLYETHYLENE TEREPHTHALATE(PP)
• HEALTH CONCERNS QUITE RESISTANT TO SOLVENTS, BASES, ANACIDS
• (A toxic chemical) leaching from water bottles that have been placed in heat for prolonged times.
• Pete plastic should not be reused because cleaning detergents and high temperatures can cause chemicals to leach out of the plastic.
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HIGH-DENSITY POLYETHYLENE
• Description: HDPE has long virtually unbranched polymer chains which align and pack easily making it dense and very crystalline (structurally ordered) .
• a stronger thicker form of polyethylene.
• Properties: resistance to moisture, permeability to gas, ease of processing.
• Typical use: Plastic bags (grocery), milk, water, and juice containers, bleach, detergent and shampoo bottles, garbage bags, dishes, some medicine bottles.
• Also used in insulation, piping, plastic/wood composites.
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HDPE
• Toxicity:
• It is generally considered a safer plastic for food and drink use.
• It can leach the endocrine disruptor nonylphenol (added to HDPE as a stabilizer), especially when exposed to ultraviolet light - Sunlight
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POLYVINYL CHLORIDE (PVC)
• Description: Synthetic Man-made Material Made From Ethylene And Chlorine
It Is The Third-most Widely Produced Plastic. Low Cost Material To Produce, Very Durable.. Properties: Versatility, Ease Of Blending, Strength, Toughness, Clarity, Transparency.
• Typical use: Toys, Clear Food (Take-out) And Non-food Packaging (Blister Wrap, Cling Wrap), Squeeze Bottles, Shampoo Bottles, Mouthwash Bottles
• Cooking Oil And Peanut Butter Jars, Detergent And, Shower Curtains, Medical Tubing,
• Wire And Cable Insulation, Carpet Backing And Flooring., Credit Cards, Piping (For Plumbing, Window Frames,, And Other Construction Materials.
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POLYVINYL CHLORIDE (PVC)
• HEALTH CONCERN- • It May Leach A Variety Of Toxic Chemicals Including, But Not Limited To:
Bisphenol A (BPA), Phthalates, Lead, Dioxins, Mercury, And Cadmium. • When Pvc Is Burned ( Via Waste Incineration, Car Or Home Fires),
Dioxins Are Formed. Dioxins Are Known Human Carcinogens And Persistent Organic Pollutants, And Are Considered One Of The Most Toxic Types Of Chemicals Ever Tested.
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LOW DENSITY POLYETHYLENE (LDPE)
• Description: LDPE polymers have significant chain branching including long side chains making it less dense and less crystalline ,thinner more flexible form of polyethylene.
• Properties: flexibility, resistance to moisture, ease of sealing, ease of processing.
• Typical use: Mostly for film applications like bags (grocery, dry cleaning, bread, frozen food bags, newspapers, garbage), plastic wraps;
• Coatings for paper milk cartons and hot & cold beverage cups; some squeezable bottles (honey, mustard), food storage containers, container lids.
• Wire and cable covering
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POLYPROPYLENE (PP)
• Description:Polypropylene is a plastic polymer with the chemical formula C3H6
• polypropylene is used for similar applications as polythylenes.
• Generally stiffer and more heat resistant - so is often used for containers filled with hot food.
• It's crystallinity (structural order affecting hardness & density) is quite high, somewhere between ldpe and hdpe.
• Properties: resistance to heat, chemicals, grease & oil, barrier to moisture.
• Typical use: Food containers (ketchup, yogurt, cottage cheese, margarine, syrup medicine containers, straws, bottle caps, including baby bottles. Other uses include disposable diaper and sanitary pad liners, thermal vests, car parts (bumpers, carpets, fixtures)
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POLYPROPYLENE (PP)
• HEALTH CONCERN- Being relatively stable
• Although it has been shown to leach plastic additives (such as the stabilizing agent oleamide) when PP labware was used in scientific experiments.
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POLYSTYRENE (PS)
• Description: It is a synthetic aromatic polymer made from the monomer styrene
• Apart from low cost, low strength foam, PS can be made as a clear, glassy, hard polymer used for things like cutlery and cd cases.
• It is highly flammable.
• Typical use: styrofoam food containers, egg cartons, disposable cups and bowls, take-out food containers, food plates, bike helmets. Cutlery & razors, compact disc & dvd cases, licence plate frames, medicine bottles, test tubes, petri dishes, model assembly kits.
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POLYSTYRENE (PS)
• HEALTH CONCERN -PS food containers can leach styrene, which is reasonably anticipated to be a human carcinogen (PS1, PS2) and is considered a brain and nervous system toxicant (PS1, PS3, PS4).
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USE OF POLYTHYLENE
PROCESS HDPE LDPE LLDPE
Making film Food packagingShopping bags
Cling filmMilk carton lining
Stretch film
Injection moulding DustbinsCrates
BucketsBowls
Food boxes
Blow moulding Detergent bottlesDrums
Squeezable bottles
Extrusion Water pipes Flexible water pipesCable jacketing
Cable coating
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PROPERTY HDPE LDPE
STRUCTURE It has a linear structure. Therefore, it can be compressed, and it is less flexible and stronger
It has lots of branches. Therefore, it is hard to compress, and it is lightweight and flexible.
Crystalline AND amorphous regions
HDPE has high crystalline and low amorphous regions (more than 90% crystalline)
LDPE has low crystalline and high amorphous regions (less than 50-60% crystalline)
Tensile Strength and Intermolecular Forces
HDPE has stronger intermolecular forces and tensile strength
LDPE has weaker intermolecular forces and tensile strength
Melting Point 135°c 115°c
Plastic resin codes 2 4
Density 0.95-0.97 g/cm3 0.91-0.94 g/cm3
Chemical properties HDPE is chemically inert, and resistant ultraviolet rays compare to LDPE.
LDPE is less chemically inert and when exposure to light and oxygen results in loss of strength.
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THIKNESS OF POLYTHYLENE
Thikness of bag determine the strength of the bag to break into smaller pieces.The the thinner the bag is the higher is the probability to its break down and mixing with soil which deteriorate the soil and marine fauna.
In india minimum thikness of polyethylene according to plastic waste management rules 2016 increase 40 micron to 50 micron.
Thikness increase –cost increase
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ENVIRONMENTAL ISSUES ON CONSUMPTION OF PLASTIC
• During polymerization process fugitive emissions are released.
• During product manufacturing various types of gases are released.
• Indiscriminate plastic waste disposal on land makes the land infertile due to its impervious nature.
• Burning of plastics generates toxic emissions such as carbon monoxide, chlorine, hydrochloric acid, dioxin, furans, amines, nitrides, styrene, benzene, 1, 3- butadiene, ccl4, and acetaldehyde.
• Littered plastics give unaesthetic look and choke the drain.
• Garbage mixed with plastics interferes in waste processing facilities and also cause problems in landfill operations.
• Plastic emit harmful voc(volatile organic compound) during incineration.
• Plastic waste dumped in ocean harmful to sustain marine life.
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ENVIRONMENTAL ISSUES ON CONSUMPTION OF PLASTIC
• Most of the plastic we consume will wind up in a landfill or in the ocean. It will never biodegrade. It will only break down into smaller pieces making it even more of a hazard for wildlife and for us. Plastic can contaminate the fresh water ,on leaching in water it easily enter food chain and harm human health.
• Plastic uses vital non-renewable natural resources that could be put to better use elsewhere. 10% of our oil production is for plastic.
• Plastic can contaminate food with toxic chemical compounds.
• Plastic waste can leach out toxic chemical like BPA(a component harden plastic),phthalates (a component make plastic flexible) causes neurological problem,cancer, birth defects,thyroid problems,hormonal disorder and cardiovascular disease.
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PLASTIC WASTE MANAGEMENT RULES, 2016 – WHAT’S NEW?
Minimum thickness of plastic carry bags increased from 40 to 50 microns
Responsibility of local bodies and gram panchayat.
Responsibility of waste generator.
Collect back system and extended producer responsibility.
Responsibility of retailers and street vendors.
Registration of the shopkeepers and street vendor to getting plastic bag.
PLASTIC WASTE MANAGEMENT
Conventional Technology
Recycling
Incineration
Landfilling
NEW Technology
Plasma Pyrolysis Technology
Liquid FuelCo-processing In Kiln
Polymer Blended Bitumen
Roads
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RECYCLING OF PLASTICS Steps Involved in the Recycling Process:
Selection: the recyclers/reprocessors have to select the waste /scrap which are suitable for recycling/ reprocessing.
Segregation: the plastics waste shall be segregated as per the codes mentioned in the bis guidelines.
Processing: after selection and segregation of the preconsumer waste (factory waste) shall be directly recycled. The post consumer waste (used plastic waste) shall be washed, shredded, agglomerated, extruded and granulated.
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ADVANTAGES OF RECYCLING PLASTIC
• Reduced oil consumption- recycling plastic cuts back on oil consumption, which is helping to extend the lifespan of our remaining fossil fuel reserves.
On average, 1 ton of recycled plastic saves 16.3 barrels of oil
• Saving energy- recycling plastic still uses energy, but it usually requires less energy than making fresh plastic. Recycling 1 ton of plastic saves the equivalent of 5,774 kilowatt-hours of electric energy.
• Reducing waste- plastics break down slowly in a landfill. However, in the ocean, for example - they can break down more quickly, but they still take a long time to biodegrade; depending on the type of plastic it could be a century or even more!
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POLYMER BLENDED BITUMEN ROADS
• Recent studies in this direction have shown some hope in terms of using plastic-waste in road construction i.e., Plastic roads. Plastic roads mainly use plastic carry-bags, disposable cups and PET bottles that are collected from garbage dumps as an important ingredient of the construction material. When mixed with hot bitumen, plastics melt to form an oily coat over the aggregate and the mixture is laid on the road surface like a normal tar road.
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PROCESS-Cleaned And Dried Plastic Wastes (E.G.: Disposed Carry Bags, Films, Cups And Thermocole) With
A Maximum Thickness Of 60 Microns Is Shredded Into Small Pieces (2.36 Mm - 4.75 Mm Size). PVC Is Not Suitable For This Process.
Aggregate Is Heated To 165°c In A Mini Hot Mix Plant
Shredded Plastic Is Added To The Hot Mix. The Plastic Gets Softened And Coated Over The Surface Of The Aggregate Giving An Oily Look In 30 - 60 Sec.
Hot Bitumen (Heated Up To A Maximum Of 160°c To Ensure Good Binding) Is Added Immediately And The Contents Are Mixed Well.
The Mix, When Cooled To 110 - 120°c Can Be Used For Road Laying Using 8 Ton Capacity Road Roller. As The Plastics Are Heated To A Maximum Temperature Of 165°C, There Is No Evolution Of Any Gas. When Heated Above 270°C, The Plastics Get Decomposed And Above 750°C They Get Burnt To Produce Noxious Gase
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MERITS OF POLYMER BLENDED BITUMEN ROADS
• STRIPPING AND POTHOLE FORMATION: bitumen film is often stripped off the aggregates because of the penetration of water, which results in pothole formation. This is accelerated during the movement of vehicle. When polymer is coated over aggregate, the coating reduces its affinity for water due to non-wetting nature of the polymer and this resists the penetration of water. Hence the penetration of water is reduced which resists stripping and hence no pothole formation takes place on these roads.
• EFFECT OF BLEEDING: waste polymer-bitumen blend shows higher softening temperature. This increase will reduce the bleeding of bitumen during the summers.
• EFFECT OF FLY ASH: it is also observed that the fly ash does not leach from this mixture
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INCINERATION• It is the process of direct burning of wastes in the presence of excess air (oxygen)
at temperatures of about 8000C and above, liberating heat energy, inert gases and ash.
• BURNING TOXIC GASES & ASH
800'C-1100'C
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ADVANTAGES OF INCINERATION
• Incineration Is An Efficient Way To Reduce The Waste Volume And Demand For Landfill Space.
• Energy Can Be Covered For Heat Or Power Consumption.
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DISADVANTAGES OF INCINERATION
• AN INCINERATION PLANT INVOLVES HEAVY INVESTMENTS AND HIGH OPERATING COSTS
• AIR POLLUTION
• GLOBAL WARMING
• DIOXIN AND FURANS
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LANDFILLING
Landfill is the conventional approach to waste management, but space for landfills is becoming scarce in some countries.
A well-managed landfill site results in limited immediate environmental harm beyond the impacts of collection and transport, although there are long-term risks of contamination of soils and groundwater by some additives and breakdown by products in plastics, which can become persistent organic pollutants.
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PLASMA PYROLYSIS TECHNOLOGY
Plasma pyrolysis is a state of the art technology, which integrates the thermochemical properties of plasma with the pyrolysis process. The intense and versatile heat generation capabilities of PPT enable it to dispose off all types of plastic wastes including polymeric, biomedical and hazardous waste in a safe and reliable manner.
In plasma pyrolysis, firstly the plastics waste is fed into the primary chamber at 8500’C through a feeder. The waste material dissociates into carbon monoxide, hydrogen, methane, higher hydrocarbons etc. Induced draft fan drains the pyrolysis gases as well as plastics waste into the secondary chamber, where these gases are combusted in the presence of excess air. .
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PLASMA PYROLYSIS TECHNOLOGY
• Continued:- The inflammable gases are ignited with high voltage spark. The secondary chamber temperature is maintained at around 10500’C. The hydrocarbon, carbon monoxide and hydrogen are combusted into safe carbon dioxide and water. The process conditions are maintained so that it eliminates the possibility of formation of toxic dioxins and furans molecules (in case of chlorinated waste.
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CO-PROCESSING OF PLASTIC WASTE IN CEMENT KILN
Co-processing of plastic waste as alternative fuel and raw material (AFR).
Co-processing indicate substitution of primary fuel and raw material by waste.
Waste material such as plastic waste used for co-processing are referred to as
alternative fuels and raw material .
One of the advantage of recovery method used in existing facility is eliminating
the need to invest on other plastic waste practices and to secure land filling.
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CONVERSION OF PLASTICS WASTE INTO LIQUID FUEL
The entire process is undertaken in closed reactor vessel followed by
condensation, if required.
Waste plastics while heating upto 2700 to 3000’c convert into liquid-vapour
state, which is collected in condensation chamber in the form of liquid fuel.
The tarry liquid waste is topped-down from the heating reactor vessel.
The organic gas is generated which can be used in dual fuel diesel
generator set for generation of electricity.
CONVERSION OF PLASTICS WASTE INTO LIQUID FUEL
COLLECTION AND SEGREGATION OF PLASTIC WASTE
STORING OF PLASTIC WASTE
SHREDDING OF WASTE
FEEDING IN HOPPER
FLOW OF WASTE INTO HEATING VESSEL IN THE PRESENCE OF CATALYST
LIQUID/ MOVEMENT OF LIQUID –VAPOR IN CONDENSER
TAPING OF LIQUID FUEL ( AS A PRODUCT)