Urban waste management
in a carbon constrained economy
Bruce Edgerton
Manager: Sustainability Policy
Key Messages
• Implications of a carbon constrained economy for urban waste management:
1. get organics out of landfill;
2. recycle-recover materials to highest-value use were possible;
3. generate energy from appropriately sorted residual material;
4. explore the next generation of energy-from-waste technologies to:
o
Generate renewable energy or transport fuels and/or sequester carbon.
• Draft Waste Strategy & consultancies (www.environment.act.gov.au)
– Provide a good starting point for discussion
– Public consultation on web
– Biochar trial & further analysis of options underway
• Final ACT waste strategy to be released this year
Context
ACT
• 1996 No Waste by 2010 released
– Resource recovery: 43% in 1996 
75% in 2005  71% in 2010
• Climate Change & Greenhouse Gas
Reduction Act (October) 2010
Federal
• Carbon Pricing Mechanism
• Carbon Farming Initiative (CFI)
– Legacy landfill emissions
– Biochar
– Soil carbon (via compost?)
Outcomes
1.
2.
3.
4.
Less Waste Generated
Full Resource Recovery
A Clean Environment
A Carbon Neutral Waste
Sector
Systems approach to waste management
Potential new waste services, infrastructure & markets
PEF = process engineered fuel
a.k.a RDF
Three pronged approach
Programs
Outcomes
1. Commercial waste scheme • Resource Recovery
> 80% by 2015
2. Organics recovery
>85% by 2020
3. Energy from waste
–
–
–
Staged implementation
appropriately sorted
residuals
i.e. no mass burn
incineration
>90% by 2025
No recoverable material sent to
landfill ie approximately 5-10%
deemed unrecoverable
• Carbon neutral waste sector
by 2020
– Implies offsets
The Role of Energy from Waste
• Adding value to under-utilised or landfilled waste streams
– Thermal Coal Substitute =
$50-150/tonne
• Creating valuable products from organic wastes
o renewable electricity
o biochar and/or liquid fuels
Conclusion
•
•
•
•
ACT Government takes its climate change responsibilities seriously
The draft ACT waste strategy is framed in this context
The final waste strategy is to be released this year
Waste management could contribute to climate change mitigation via:
– avoided emissions from landfill
o 2.5% of total GHG emissions
– Avoided emissions via recycling
o As important as landfill GHG emissions – but
o doesn’t impact on the ACT’s GHG inventory
– generating renewable energy
– sequestering carbon &/or generating renewable transport fuels
Extra Slides
draft waste strategy consultation
•
Released
8 Dec 2010 to 28 Feb 2011
– draft ACT Sustainable Waste Strategy 2010-2025
– URS- EcoWaste & Inovact consultancy reports
•
Held
– 6 community forums
– 1 waste-industry forum
– 3 presentations at waste conferences 2010-11
•
Results
– All submissions made public
(www.environment.act.gov.au/waste)
– Generally quite positive feedback
o
o
o
20,000 participants & 34,000
submissions
•
Third bin was 45 out of 1000 issues
–
ACT has high service provision
expectations... and Queanbeyan already
has a garden-waste bin!
Including for energy-from-waste... providing it was staged and/or “right sized” not incinerated
– Want more services
o
“Time to talk- Canberra 2030”
E-waste recycling
Bulky waste collection
Garden waste collection
1.
2.
3.
4.
5.
C&D largest material stream
Garden waste
Commercial waste
Household waste
Urban forest & biosolids
underutilised
Energy-from-waste: technology options
• Landfill gas
• In-vessel anaerobic digestion
• Direct combustion
• Process Engineered Fuels (PEF) - for export outside the ACT
• Advance thermal options
• Gasification
• Slow pyrolysis
• Flash pyrolysis
• Plasma et al.
Appropriate feedstocks for EfW
Dry – tonnes/yr of dry matter
Wet - tpa dry (tpa wet)
• C&D timber
• Biosolids (sewage sludge)
– 15-30,000
• Urban forest material
– 10,000 and growing
• Dry commercial waste (PEF)
– 10-25,000
• Garden waste
– 180-240,000
– 13-15,000
(30-45,000)
• Sorted commercial organics
– 8-16,000 (20-35,000)
• Sorted domestic organics
– 10-20,000
(30-40,000)
Green – available now (3-10MW)
Orange – potentially available by 2015
Red – post 2015 or not available
Biochar Trial
manufactured by AnthroTerra
using low temperature (≈450oC)
pyrolysis
Results
• Sequestration
Biochars
1.
–
2.
– C&D timber + dry green waste
≈ 19 MJ/dry tonne
– Biosolids & household organics
= 12.5 - 13.8 MJ/dry tonne
• Agronomic quality???
– Looks good
– High Zn, Pb, Cu, Cr in MSW
3.
4.
torrefied with biosolids at 250oC
after pyrolysis
C&D timber + biosolids
household organics (from MSW)
–
5.
micro & macronutrients added
after pyrolysis
C&D timber
–
– 33-54% kg biochar/kg dry input
– 71-92% stable carbon
• Energy yield
C&D timber
from SITA’s Kemp’s Creek residualwaste MRF (SAWT) processing
Liverpool’s residual waste bin
Urban forest material (green
waste) + biosolids
Biochar Pot Trials
ANU Fenner School of Environment & Society
• >1600 pots
• 0.5-6% biochar blended with
– compost made from
garden waste in the ACT
– a local top soil
• 5 species
–
–
–
–
–
Breccia
Pansy
Acacia
Annual grass
Perennial grass