Urban waste management in a carbon constrained economy

Urban waste management in a carbon constrained economy

Bruce EdgertonManager: 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

ContextACT• 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?)

Outcomes1. Less Waste Generated2. Full Resource Recovery3. A Clean Environment4. A Carbon Neutral Waste

Sector

Systems approach to waste management

Potential new waste services, infrastructure & markets

PEF = process engineered fuela.k.a RDF

Three pronged approachPrograms

1. Commercial waste scheme2. Organics recovery3. Energy from waste

– Staged implementation– appropriately sorted

residuals– i.e. no mass burn

incineration

Outcomes

• Resource Recovery> 80% by 2015>85% by 2020>90% by 2025No 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 wasteso 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 landfillo 2.5% of total GHG emissions

– Avoided emissions via recyclingo As important as landfill GHG emissions – buto 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 8 Dec 2010 to 28 Feb 2011

• Released– 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 Including for energy-from-waste... providing it was staged and/or “right sized” not incinerated– Want more services

o E-waste recyclingo Bulky waste collectiono Garden waste collection

“Time to talk- Canberra 2030” 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!

1. C&D largest material stream2. Garden waste3. Commercial waste4. Household waste5. 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

• C&D timber – 15-30,000

• Urban forest material – 10,000 and growing

• Dry commercial waste (PEF)– 10-25,000

• Garden waste– 180-240,000

Wet - tpa dry (tpa wet)

• Biosolids (sewage sludge)– 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 2015Red – post 2015 or not available

Biochar Trialmanufactured by AnthroTerrausing low temperature (≈450oC) pyrolysis

Biochars1. C&D timber

– micro & macronutrients added after pyrolysis

2. C&D timber – torrefied with biosolids at 250oC

after pyrolysis 3. C&D timber + biosolids4. household organics (from MSW)

– from SITA’s Kemp’s Creek residual-waste MRF (SAWT) processing Liverpool’s residual waste bin

5. Urban forest material (green waste) + biosolids

Results• Sequestration

– 33-54% kg biochar/kg dry input– 71-92% stable carbon

• Energy yield– 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

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