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Converting Waste to Energy presented at: Association of Vancouver Island & Coastal Communities AGM and Convention

11 April, 2015 Courtenay, BC

Waste to Energy

•  Thermal Systems: •  Thermal Treatment or Conditioning •  Conversion Technologies •  Mass Burn Combustion •  Gasification, Pyrolysis, •  Or just plain – Incineration

•  Biological Systems •  Anaerobic digestion •  Landfill gas recovery

•  The role of waste to energy (WTE) •  How WTE works •  What does it cost? •  Environmental and health impacts

•  Common myths

•  Questions and discussion

What we will talk about today

3 4

•  4th R - Recovery of energy and materials after the first 3Rs, prior to disposal

Where does WTE fit in?

Reduce  

Reuse  

Recycle  

Recovery  

Residuals  

The role of WTE in an Integrated System

•  With recycling and organics treatment:

Recycling

Landfill Landfill

ThermalTreatment

OrganicTreatment

How Thermal WTE works

•  Technologies offer different ways of releasing the energy in the waste

•  Conventional WTE systems are essentially power plants using waste as fuel instead of natural gas or wood

•  Advanced WTE systems use heat to convert the energy in the waste into a gas that can be burned for power, or converted to fuel (for burning)

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Conventional waste to energy

Electricity

Combustion Energy RecoveryFeedstockPreparation Flu Gas Cleaning

Bottom Ash Fly Ash

Exhaust

(60160 Waste to Energy 14Feb06.vsd)

Steam Heating

Advanced thermal technologies: gasification/pyrolysis

Electricity

Gasification orPyrolysis Syngas CleaningFeedstock

Preparation Energy Recovery

Char / Ash

Exhaust

Gas Turbineor Recip.Engine

Steam

Residue /Ash

(60160 Waste to Energy Pyrolysis 14Feb06.vsd)

Burnaby, BC Mass Burn Facility (280,000 T/a) Wainwright WTE (10,000 T/a)

•  Showing the process steam line for energy utilization

Gasification Plant in Edmonton 80,000 T/a

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•  Anaerobic Digestion (AD) •  Bacteria degrade organics and form methane •  Methane is captured and cleaned •  Can be burned as fuel, or •  Upgraded to natural gas quality (to be used as fuel)

Biological WTE

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Anaerobic Process

Organics separated from waste stream

Pulping and decontamin-ation of feedstock

Material fed into reactor

Biogas recovered from reactor

Digestate removed from reactor

Solids dewatered

Energy recovery

Aerobic composting

Liquid fraction recycled

AD Pictures

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Bioreactor Landfill

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Courtesy SSWM

Energy Comparison

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Potential kWh per tonne of waste

0  

100  

200  

300  

400  

500  

600  

700  

800  

Thermal  WTE  Gasifica>on  WTE  

Anaerobic  Diges>on  Bioreactor  Landfill  

Waste Diversion Potential

•  Thermal WTE •  Takes 100% of

residual waste after recycling •  75% converted to

energy •  25% to landfill as ash

•  Biological WTE •  Takes 35 – 40% of

waste (Organic part) •  60% to 65% still goes

to landfill •  About half of the

diverted organics become compost

•  The rest goes towards making energy

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Landfill Reduction

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What still goes to landfill in % by weight

0  

20  

40  

60  

80  

100  

120  

Thermal  WTE   Gasifica>on  WTE   Anaerobic  Diges>on   Bioreactor  Landfill  

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Cost comparison

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$ per tonne comparative estimates, including capital repayment

0  

50  

100  

150  

Thermal  WTE   Gasifica>on  WTE   Anaerobic  Diges>on   Bioreactor  Landfill  

Economies of Scale for Thermal WTE

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Courtesy Ramboll (developed for York – Durham)

Long term WTE costs versus Landfill

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Environmental Issues

•  Air emissions •  Emission standards more stringent than for most

wood fired power plants or industrial boilers •  In Europe, air emissions from WTE considered

irrelevant compared to industry and transportation •  Residues from thermal systems

•  Bottom ash generally safe to dispose in landfill or use as cover

•  Fly ash (5%) needs to be stabilized before landfilling •  AD residue is compost, which can be land applied

Dioxin Emissions in the USA

Source: (P. Deriziotis, MS Thesis, Columbia University, 2003; data by U.S. EPA)

Reduction of Mercury from WTE in the USA

Source: Waste-to- Energy Research and Technology Council (WTERT)

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Comparing GHG Emissions

Tonnes CO2e Reduced per Tonne Material Handled

-0.5

0.5

1.5

2.5

3.5

Steel Paper Plastics Yard &Garden

FoodScraps

Yard &Garden

FoodScraps

ResidualWaste

ThermalTreatment

Tonn

es

Recycling

Composting Anaerobic Digestion

GHG Emissions from Thermal Electricity Production

0

500

1000

Coal Natural Gas(CCGT)

MSW BC EnergyIntensity

CO

2e e

mis

sion

s (k

g/M

Wh)

•  Thermal WTE has no future •  False: there are 800 plants worldwide and over 400

in Europe, with many new ones on the way •  Thermal WTE will reduce recycling

•  False; those countries with the highest WTE also have the highest recycling

•  WTE will eliminate the need for landfills •  False: landfills will be needed for ash, for downtime

and to handle growth

Myths – true or false

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•  Revenues from WTE can pay for everything and put money back into the community •  False: Capital and operating costs are too high to be

fully offset by energy revenues •  Emerging technologies carry a high risk

•  True: Many promises are made, but most cannot deliver. See Plasco example

•  Thermal systems can cause health issues •  False: Modern systems have not been linked to

health issues

Myths (continued 2)

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•  WTE is too expensive for smaller communities: •  True: In most cases, maximized recycling and landfill

will be less costly (if landfill capacity is available) •  AD is growing worldwide and pays for itself:

•  False: AD plant construction in Europe has slowed to a crawl because subsidies have been reduced.

•  Current energy prices are hurting WTE projects •  True: Even large scale plants need good energy

revenues to keep tipping fees reasonable

Myths (continued 3)

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•  WTE facilities will never be sited anywhere close to anyone •  False: see location of WTE plant in downtown Paris

Myths (continued 4)

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THANK YOU QUESTIONS AND DISCUSSION