matl recycle

8/13/2019 Matl Recycle

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1Copyright Anders Damgaard & Morton A. Barlaz, NC State University

Material recycling

Outline Objective of material recycling

Purpose of reuse in industry

Recycling Components of the MSW Stream

Aluminum Glass

Steel

Plastics

Paper

Tires

Copyright Anders Damgaard & Morton A. Barlaz, NC State University


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Objective

Examine recycling process for each material, alternativetechnologies, projected markets

Demand and economics have a significant influence on

recycling activity Is it consistently marketable?

What limits recycling?


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Purpose of reuse in industry

Ensure raw materials to national industry: Paper, glass, metal.

Economy: Waste materials are cheaper than virgin materials at thegate of the plant (price of raw materials, transport of raw materials)

Manufacturing is cheaper (energy, emissions, waste & costs) Life-cycle assessment shows overall benefits (less virgin materials

used, less landfilling and maybe less treatment)

In the latter case, global assessment may be different than that of the

industry and regulations / incentives may be needed to improve recycling


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Paper: Remanufacturing 1Chemical-mechanical re-pulping

Chemical-mechanical re-pulping is used for higher-quality products requiringremoval of ink and maybe bleaching. Chemical-mechanical re-pulping including thecleaning process typically consists of seven steps (Virtanen & Nilsson, 1993):

Feeding and pulping including pH adjustment (caustic soda, aluminum sulfates)and addition of dispersing agent (e.g. glycol ether)

Pre-cleaning (mechanical) removes solid foreign items using centrifuges andpressure sorters

Refining provides washing, sorting and milling of the pulp

De-inking and pigment removal by chemical (water glass, etc,) and mechanical(flotation) treatment steps.

Final cleaning (mechanical) Thickening and bleaching (heating with hydrogen peroxide or sodium

hypochlorite) and storing

Drying


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Paper: Remanufacturing 2

Mechanical re-pulping Mechanical re-pulping is used for less demanding paper qualities such as brownpaper, boards, egg containers, etc. Mechanical re-pulping including the cleaningprocess typically consists of six steps (Virtanen & Nilsson, 1993):

Feeding and pulping including pH adjustment (caustic soda, aluminum sulfates)and addition of dispersing agent (e.g. glycol ether).

Pre-cleaning (mechanical) removes solid foreign items using centrifuges andpressure sorters.

Refining provides washing, sorting and milling of the pulp.

Final cleaning (mechanical) to remove items released in the refining step.

Thickening reducing the water content and allowing for storing. Drying


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Paper Recycling 1: Major Grades

There are about 80 grades of fiber

Major grades:

1. Pulp substitutes

Unprinted trimmings from envelopes and high grade paper

Generated in paper mills only

Primarily reused in tissue, also in book stock


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Paper Recycling 2: Major Grades

Post Consumer

2. High grade deinking

Office white paper

3. Old corrugated (OCC)

4. Old newsprint (ONP)


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Paper Recycling 3 Major Grades

5. Residential mixed paper (RMP)

office waste, third class mail, boxboard (cereal boxes), magazines,telephone books, OCC, coated packaging

6. Mixed office paper7. OMG - old magazines

8. OTP - old telephone books


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Paper Recycling 4: ONP

~4% of MSW in 2010 (includes 18.8% advertising)

~70% recovery rate

Uses:

largest use is in new newsprint

recycled paperboard

cereal & shoe boxes, tablet backs

cellulose insulation, roofing felt

animal bedding

export


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Paper Recycling 5: ONP

Specifications

#6 news -


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Cardbox Composition

Linerboard - The inside and outside of a box that confers strength

Medium(fluting) - fluted section in between linerboard

Containerboard a box


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Paper Recycling 6: OCC

~12% of MSW (2001)

~71% recovery rate

Uses:

Container board (linerboard and corrugating medium)

news boxes require 20% OCC

construction products

wallboard, roofing felt

Paperboard

Dec. 2012 Prices 70-130 $/ton


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Paper Recycling 7: OFF

There are a number of grades of office paper:

office paper only

white copy and pad paper

standard office mix that may include: envelopes (with and without plastic)

mail including coated papers

colored paper

folders and card stock


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Paper Recycling 8: Office Paper (OFF)

ISRI Grades & 2006 Price:

127: sorted white ledger

119: sorted color ledger Mixed Office Paper

Clean, sorted ledger & writing papers, free of brown grades,cardboard, boxboard, may contain up to 10% groundwood

paper fiber content


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Paper Recycling 9: Office Paper (OFF)

Problems

no consistent definitions/varying markets

adhesive labels, stamps

paper clips, plastics grey and brown products (brightness)

Uses:

historically tissue paper

printing and white (somewhat grey) paper is a newer use

Federal agencies must use paper with 30% recycled content by1998


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Paper Recycling 10: Old Magazines (OMG)

Coated magazine and catalog papers

OMG facilitates ONP ink flotation

Ample market capacity given high demand for ONP


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Paper Recycling 11: Residential MixedPaper (RMP)

May contain OMG, books, ONP, third class mail, envelopes,foodcartons and OCC

A relatively low quality fiber but incentives to use:

cheap and in large supply Uses are limited due to fiber length:

Egg cartons, roofing felt, fruit, separators

Boxboard and wallboard backing


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Paper Recycling 12: RMP

May be used where shortages of other paper grades develop

Price will depend on availability of better papers

Solid waste manager must figure out what to separate and what to

leave as mixed paper Flexibility is key


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Paper Recycling 13

Effects of recycling

weaker fibers

decreased burst strength

stiffer paperThis decreases ability to light weight a box

Losses During Recycling:

OCC: 10-15%

OMG: 40-60%

OFF: 8-20%


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Paper Recycling 14: European paper flows

Ref: CEPI, 2004

Million tonnes


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Paper Recycling 15: Paper market prices

Ref: Danfiber, 2009


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Container Glass: Short version

Glass is made primarily from sand (quartz), soda and lime; none-renewable but not scarce resources

Problems with post-consumer glass: Mix of colors, foreign objects

(ceramics, metal caps). More than a few percent of wrong coloraffects the color of the remanufactured product

Major benefits: Energy savings in production

Products: Glass containers/bottles, insulation material


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Glass: Types

Soda-lime glass, which is used for bottles, jars, drinking glassesand window glass, is typically produced from 70-75% quartz sand(SiO2, particle size 0.1-0.4 mm), 12-16% soda (Na2O, Na2CO3),10-15% lime (CaO, CaCO3) and traces of other materials.

Crystal glass, which is used for high-quality drinking glasses, vases,art etc, is typically produced from 54-65% SiO2, 18-38% PbO, 13-15% Na2O or K2O and various other oxides.

Borosilicate glass (Pyrex glass), which is used for laboratory glassware, kitchen glass ware and high temperature lamps, is typicallyproduced from 70-78% SiO2, 7-13% B2O3, 4-8% Na2O and K2O,and 2-7% Al2O3. Borosilicate glass is corrosion and temperatureresistant.


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Container Glass Recycling 1

Glass is about 5.5% of MSW / 90% containers

beer and soda

food jars

wine/liquor ~55% clear (flint)

~6% green (50% imported)

~38% brown (amber)

Only container glass can be recycled


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Recycling processing

Color separation is critical due to tight specs on end product(glass containers)

optical sorting possible at regional level Source separation is most efficient as breakage reduces ability to

separate colors


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Pricing ($/ton) Dec. 2009

end userClear 29Brown 17

Green 8 Market for recycled glass

historically stable (except green) market share is shrinking due to plastic


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Uses

new beverage containers

these alternates provide a market for mixed color glass

substitute for stone and sand in asphalt (up to 20%) fiberglass insulation

drainage material

1992: California required fiberglass manufacturers to use 30%

recycled glass


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Processing

Shipped either crushed or loose

Cullet (crushed glass) requires less energy to melt compared to

sand & already contains additivesSpecifications

clear - 95%, green and brown - 90%

no metal, rocks, ceramic


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Aluminum: Short version

Aluminum is obtained under great energy expenses from minedbauxite, a limited non-renewable mineral

Problems with post-consumer aluminum: Few if clean from other

metals Major benefits: Energy savings in production, preserving a resource

with a large environmental signature

Products: Any new aluminum product. No loss of quality


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Aluminum Recycling

What can be recycled?

Essentially everything - the only limit is cleanliness and pricepaid

Price structure (Dec. 2012):delivered to end user

UBC - Used beverage can 1200-1800 $/tonClean scrap higher Foil lower


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Market Conditions

The aluminum companies will buy as much as they can get

Recycled aluminum is used for: New beverage cans - 27%

Building and construction - 21%

Transportation - 21%

Electrical goods - 9%

Other - 23%

Major barrier to aluminum recycling is collection

National UBC recovery rate is


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Aluminum Recycling

Processing of used aluminum

Shred, flatten or bail for transport, cans are actually blown into atrailer

Tremendous energy savings realized with use of recycledaluminum

~95% energy saving in production

Eliminates energy for mining

Requires energy for collection


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Iron / steel: Short version

Iron / steel is obtained under great energy expenses from minedore. Iron is a non-renewable mineral, but rather abundant

Problems with post-consumer : Few if clean from other metals (tin

as plating, lead as solder) Major benefits: Energy savings in production, preserving a resourcewith a large environmental signature

Products: Any new iron product. If tin or lead have penetrated intothe iron, the quality may be lower


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Steel Recycling

7.9% of solid waste stream

22% of steel is food and beverage cans

58% -appliance, furniture, tires, other durables (excludes - cars,

construction waste) Ferrous metal is easily separated from shredded MSW with

magnets but this is quite rare (~95% pure)


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Steel Recycling Depending upon the furnace type - can utilize 20 to 100% scrap as

raw material Market is soft and fluctuates but overall market capacity is adequate

Controlled by price at scrap yard

White goods - dealers may charge if they contain CFCs

Pricing (Dec. 2012)Cans 100-200 $/ton

Ref: Danfiber, H.J. Hansen, Westmetall, 2009


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Plastics Recycling

~12% of MSW stream by weight

Plastics - polymers that can be formed into shapes, typically by theapplication of heat and/or pressure

Two categories thermoplastics: soften when heated and can be remolded

(recycled)

85% of manufactured plastic

thermosetting: do not soften when heated and cannot beremolded, limited opportunity for recycling

15% of manufactured plastic


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Plastics Production

Raw materials:

ethylene oxide, benzene

Raw materials ---> resin (petrochemical industry) ~300

Resin ----> molded products (independent producers) 1000's hundreds of types of resins


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Plastic Recycling

Plastics can only be recycled if separated by resin type

Currently no mechanical processes are available to sort plastic frommixed refuse

Sortation of HDPE/PET/PVC can be done


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Types Of Thermoplastics: HDPE

High density polyethylene (HDPE)

Consumer products:

Containers for milk, water, foods, oil (~0.3% of MSW)

Major division for recycling: translucent HDPE - milk and water jugs (0.05 0.30 $/lb baled)

pigmented HDPE - household industrial chemical containers(HICs) (0.13 0.22 $/lb):

oil, detergent, shampoo


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Types Of Thermoplastics: HDPE

Recycle market:

Need for translucent/pigment separation is not alwaysnecessary

some MRFS ship mixed PET/HDPE (lower value) Products:

Garbage bags, flower pots, speed bumps, drain pipes, autoparts, films, toys,

Sandwich layer in bottles


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Types Of Thermoplastics: PET

Polyethylene terephthalate (PET)

Consumer products: soda and liquor bottles

beverage bottles - ~0.4% of MSW

custom PET is other recyclable component Major recycled markets:

carpets, polyester fiberfill, auto parts, textiles (~70%)

approved for contact with food (1998)


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Types Of Thermoplastics: PET

The most widely recycled resin because 30% of the U.S.population lives in bottle bill states

Also the most valuable plastic resin

ethylene glycol plus dimethyl terephthalate


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Types Of Thermoplastics: Polystyrene

(PS) (Styrofoam)

Consumer products:

Fast food packaging, packing for shock insulation, eatingutensils, dairy containers

Recycled markets: Packing for shock insulation, desk accessories

Recycling:

Technically feasible

Limitations: cost due to light weight

cost to wash


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Types Of Thermoplastics: PVC

Polyvinyl chloride (PVC)

has been a shift away from use in household containers

it burns before PET melts

Polypropylene (PP) Films, Textiles


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Products for which the majority is made

from one resin

Item Resin/ Share of Product

Food Packaging Film LDPE/ 65%

Carryout bags HDPE/ 63%

Dairy containers HDPE/52%Pipe and conduit PVC/ 96%

Trash bags LLDPE/ 62%

HIC bottles HDPE/ 80%

LLDPE - Linear Low Density Polyethylene


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Plastic Recycling

What left must be treated as commingled plastic

it can be made into plastic lumber

development of construction specifications

expensive relative to wood for all but high end uses, needspecific uses

new life as CCA treated lumber is banned

Other sources of pure material:

pallet wrap process trimmings


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Barriers To Recycling

1 Collection/participation

2 Cost of resin fluctuates


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Wood Waste

Pallets, tree trimmings, land clearing debris

Typically comes in Monoloads"

Markets BioCycle,Jan., 1995: $/ton

Paper pulp 2-5

Wood composite materials 5-35

Fuel (8500 BTU/lb) 0-20

Mulch 0-10

Landfill cover 0-2

Road stabilization ?

animal bedding 0-20

The distance to market is critical as the value is low: transportationcost - 0.1 $/ton-mi


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Tire Recycling

Generation rate ~ 1 per person per year

290 million generated in 2003

Proper inflation = source reduction!!

Unique problems Whole tires do not stay buried in landfills

Serve as breeding grounds for mosquitoes

Present a special fire hazard


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Tire Recycling

Alternative uses for tires

Retreading

Direct reuse

combustion tire derived fuel (TDF) Reuse in other products


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Tire Recycling

A tire contains three components:

Rubber (~12 lb)

Fabric (~4 lb)

Metal (~4 lb) In several layers:

Rubber

Beads

Fabric and steel Rubber / tread


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Tire Recycling

Combustion

As "tire derived fuel" in industrial boilers (~50% of all tires)

Cement kilns where the lime in cement neutralizes the SO2

Whole or 2" chips Paper industry boilers

2" chips

Utilities -- ?

http://www.rma.org/scrap_tires/


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Tire Recycling

Reuse in other products

Drainage material CE Applications (14.2% in 2001)

leachate distribution

septic fields erosion control

subgrade fill

backfill for walls and bridge abutments


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Tire Recycling

Crumb rubber for low end rubber products (11.7% in 2001)

car mats

mud flaps

shoe soles carpet backing

tires for wheel barrel and tricycles

recreational surfaces (e.g. tennis courts)


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Copyright Morton A. Barlaz, NC State University 58

Low end rubber products (contd.)

Overall demand is not adequate

Over 50% of U.S. demand for rubber is for tires Any time crumb rubber is produced, steel and fiber remain

for disposal

Use in asphalt rubber mixtures

Technically feasible but typically not as viable as combustion

Tire Recycling


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Tire Recycling

SUMMARY1. Use in cement kilns, and use in other boilers as TDF works well

and is dominant outlet2. Demand for use as a drainage material varies with location


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Material Markets

Prices are volatileBLS OCC National

0

50

100

150

200

250

300

12/1/1986 3/1/1988 6/1/1989 9/1/1990 12/1/1991 3/1/1993 6/1/1994 9/1/1995 12/1/1996 3/1/199

Deflated by the ppiBase 12/86

MonthlyPriceIn

dex

Overview of Futures Markets


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Material Specifications

Often subjective but reputation is critical

MRFs and processors must have end users (purchasers)

Often will take less money for sales guarantees

Specifications vary with the plant capability

with material demand over time

matl recycle

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