WASTE AND RECYCLING

WHY DO WE NEED TO RECYCLE?Waste per Person per YearUnited States 0.88 tons

2.4 kilograms (10 pounds) per day!

http://www.epa.gov/epawaste/nonhaz/municipal/images/2012_totl_msw_gen_fig5_lg.jpghttp://blogs.ft.com/energy-source/files/2011/01/Landfill.jpg

Only 32.5% was recycled

WHY RECYCLING IS PROBLEMATIC•Ideally material should be free of

contaminants

•Many consumer items are made from

more than one material

•Materials are optimized for specific uses

Solutions:

Air classification (to remove light objects)

Sink-Floating techniques

Hand held spectrometers

http://blogs.ft.com/energy-source/files/2011/01/Landfill.jpg http://www.epa.gov/solidwaste/nonhaz/municipal/images/waste_hierarchy_green_400pxw.png

PAPER

Incineration

VS

http://www.recyclepower.org/images/arrowpaper.JPG

-Saves more energy -Create 3 times more jobs

http://campaign.tetrapak.com/lifeofapackage/styles/images/paper-products.jpg

http://www.dejavulaser.com

DEINKING/REPULPING

Recycling without deinking/bleaching- napkins, toilet tissue, etc

Recycling with deinking-Chemical-Flotation/washing-Mechanical-Steam explosion-Ultrasound-Enzymes

Paper Recycling Plant in Indonesiahttp://www.youtube.com/watch?v=_J0BvswbEes

Bottom line: New generation of tonners needs to be devised!

Stickies are another problem in paper repulping

EXTENT OF RECYCLING OF PAPERNonpaper Uses•Wood-based composites•With polyethylene/polypropylene trunk liners for cars, door panels, etc •With synthetic fibers – nonwoven mats•With binders (resins, asphalt) – acoustical insulating boards•With wood, gypsum – boards

Paper Mill Sludge

https://c2.staticflickr.com/4/3590/3365375855_9fdbb8253d.jpg

•Boards

•Tiles

•Plastics

•Ethanol

•Feed for cattle

•Litter for pets

PLASTICSMost Used Plastics

41% Polyethylene

23% Polyvinylchloride

21% Polypropylene

11% Polystyrene

4% Styrene-acrylonitrile

Where

27% Packaging

20% Building

13% Consumer products

http://www.projectgreenbag.com/recycling-codes-on-plastics/

RECYCLING

•Foamed insulation

•Fibers (various applications)

•Shower curtains

•Paint brushes

•Draining pipes

•Trash cans

•Grocery bags

•Traffic barrier cones

•(non-food)

Plastic recycling rates are… dropping down

High costs of collecting and sorting

RECYCLING METHODS

•Additional stabilizers should be added (exclusion polypropylene)

•Different polymers should be separates (e.g. in carpets)

Bottle: PETECap and label: polypropylene

SolutionAll polyester bottleInk jet printing instead of label

POLYMER RE-USE AND RE-DISIGN-Creation polymer blends to minimize separations

- Improve properties of recycled materials

Compatibilizers – block or graft copolymers

Graft polymer

Example:Polypropylene grafted with maleic anhydride becomes compatible with nylon-6,6

PYROLYSIS OF PLASTICS- Polymers can be converted to their monomers for purification and repolymerization

•Nylon-6 → caprolactam

•Polymethylmethacrylate → cyanoacrylate (92-100%)

•Poly(α-methylstyrene) → methylstyrene (95-100%)

•Polytetrafluoroethylene → fluoroethylene (97-100%)

•Polystyrene → styrene (up to 100%)

Uses of Pyrolyzate

•Repolymerization

•Feedstock for petroleum refinery

•Fuels