1. Options for Valorizing Solid Wastes
Armando McDonald
Professor
Renewable Materials Program

2. Presentation overview
Municipal solid waste
Industrial waste
Plastic recycling & conversion
Biomass conversion into fuels
Heat and electricity
Summary

3. Municipal solid waste 250 million tons MSW in the US (2010)
56% discarded
34% recovered
12% converted to energy
12% plastic in landfills (20% by volume)
12% of plastics recovered
27% HDPE and 21% PET recycling rates
42% biomass (wood/textiles/food/yard)

4. Paper recycling waste Cardboard recycling Newsprint recycling
Reject fibers & labels/tape/hot-melt
Newsprint recycling
shrinkwrap/bags/labels/etc.
Obtain mixed plastic waste (25 tons/d small plant)

5. Plastic valorization Mechanized sorting to add value
12% of plastic recovered (segregated)
27% HDPE is recycled (milk jugs, $500/ton)
21% PET is recycled (coke bottles, $500/ton)
Increase level of recycling for local use
Most is sent to china for processing
Mixed plastic stream (-$24/ton)
Variable properties
Converted to plastic/composite products
Converted to liquid fuels

6. Mixed plastic waste options
Mixed waste ground, compounded & processed into products
HDPE (strength 17 MPa)
Mixed (strength 9 MPa)
Properties can be enhanced by:
Additives (17 MPa)
Wood fiber (13 MPa)

7. Pyrolysis of mixed plastics to fuels
Can use mixed plastic grades 1-2,4-7 + rubber
Pyrolysis “thermal cracking” to hydrocarbons
Can be used directly as heating fuel
Refined to diesel & jetfuel
Pyrolyzed HDPE product profile C7
C12
C14
C10
C16

8. Biomass valorization Wood & yard-waste Value added chemicals
Fuel pellets
Cellulosic ethanol & bioplastics
Value added chemicals
Food waste
Lactic & succinic acid

9. Gasification of waste/biomass
Can handle a range of feed-stocks
High temperature conversion to produce synthesis gas (syn-gas)
Combustion to produce electricity
turbines or engine
Converted to chemicals
Methanol, hydrocarbons

10. Waste/Biomass Production of syngas Gasification Gas Cleaning Syngas
Fischer-Tropsch (FT) synthesis
Methanol synthesis
Synthesis of liquid
fuel hydrocarbons
Methanol-to-gasoline (MTG)
Jet fuel/Diesel
Gasoline

11. Pyrolysis of biomass Wood, textiles, food, yard-wastes
Pyrolysis “thermal cracking” to bio-oil & biochar
Bio-oil
used as heating fuel
upgraded to biofuel
Biochar
Soil amendment
Remove contaminants

12. Heat & electricity

13. Heat & electricity Reduces landfill volume 1 MW supply 1000 homes
10 MW plant uses 10 BDT wood/hr

14. Summary Gain value Reduced landfill volume
Segregation of plastics for recycling
Conversion of mixed plastics to fuels & materials
Biomass can be converted to fuels & chemicals
Produce heat & electricity

15. Questions?