Transcript Covington Waste-To-Energy Plant

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Agreeing on The Goals
Charting A Path Forward
Open Communication At Every Step
Managing Timelines and Budgets
 A big driver was our need to provide more funding for our city parks and
recreation budget to help the children and youth of our community.
Thought if we could save big in one area, we could put more funding into
another without having to raise taxes. Always a good thing.
 Looked at waste material going into the landfill, the huge money being spent
there, and thought there must be a way to stop that process and turn “dirty
into dollars” for the city….recycling it into energy.
 Thoroughly researched disposal options, and ran a lot of numbers to arrive at
a solid recommendation for the city.
 Kissed (at least interviewed) a few frogs before I found a company with the
technology, experience and high trust factor we had to have.
Innovation
Collaboration
Innovative Collaboration
Collaborative Innovation
Along with Some Collaborative and Innovative Cat Herding
Held together with a commitment to
“Do the right thing, for the right reason, in the right way.”
The following slides explain how the waste
gasification technology works and the benefits it is
bringing to Covington.
After all this extra homework, I achieved nerd status.
But not quite a geek…yet!
The clean conversion of biomass into a combustible fuel gas
in an oxygen-starved environment
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This is NOT Incineration.
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Converts multiple types of feedstock to a consistent gas
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A thermo-chemical process producing a clean fuel gas by
breaking down solids at the molecular level.
About 95% of what goes in comes out as fuel gas. The
other 5% is a charcoal biochar with many uses.
1941 Adler Diplomat
powered with a gasifier
Air
Air
Evaporate moisture from
the feedstock
Drying
Feedstock breaks down
to gas and tars
Pyrolysis
3000 degree F heat layer
cracks tars
Carbon reforms with
steam to create CO and
H2
High Heat
Reduction
Grate
Residue
Rotating Grate shaves
biochar layer
Residue box for biochar
removal
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Woodchips
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Urban yard waste, ROW trimmings
Bark or pulp operation waste wood
Manufacturing scrap
WWTP Sludge
 Food processing residue and
manufacturing waste
 Scrap tires and rubber
products
 Agricultural and animal
waste
 No glass, metals, rock, slag
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Currently Being Utilized Here and Worldwide
• Electricity: Gas or steam turbines and ORC generators
• Steam: Boiler and community heating systems
• Direct Thermal: Kiln Operations & Sludge Dryers
• Combustion: Industrial thermal oxidizers
50,000 Hours of
Commercial
Production
City Wood Waste:
10 tons per day chipped
and used as fuel
Sludge From Sewer Plant:
2 tons per day utilized rather
than trucked to landfill
Wood Chip and Sludge are combined, dried and
sent to the top of the Gasifier by conveyor
equipment
Thermo-chemical Gasification
process converts feedstock
to fuel gas without incineration
1. Fuel Gas is Combusted
in a thermal oxidizer to
cleanly produce heat
2. Oil Is Heated to 350
Degrees
3. Hot Oil Drives
General Electric
Organic Rankine Cycle
Generator to make
electricity
(125 Kw)
Feedstock Flexibility Mitigates
Future Risk of Change
Annual Landfill Diversion:
• 3,600 tons of wood waste not landfilled
• 720 tons of sludge not landfilled
• = Over 4,000 tons of waste put to work for the community
Carbon Footprint Reduction:
• Prevents release of 425 tons of carbon dioxide into the
atmosphere each year by reducing electrical use WWT, as
well as fossil fuels previously used in transportation.
• According to DOE, that translates to GHG emissions
expected annually from 80 automobiles or carbon dioxide
emissions from over 35 homes.
Many Moving Parts To Coordinate
City Council Members
Public Works Department & City Engineers
Waste Water Treatment Plant Operators
Tennessee Municipal League
Tennessee Department of Environment &
Conservation
PHG Energy
General Electric
• Technology: Deploying Gasification System In A
New Configuration
• Feedstock: Utilizing WWTP Sewer Sludge,
Prepping city wood waste
• Energy Production: Using General Electric ORC
Generator with Thermal Oxidizer and Heat
Exchanger
• Financing: TML Bond Funds
Start with a Real
Need
+ Motivation
+ Innovation
+ Collaboration
+ Commitment
= Success*
*As long as you’re doing the right thing, for the right reason, in the right way.
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How do you start the gasifier? Using a standard bag of charcoal.
How do you stop the gasifier? It uses a small amount of air to sustain the
process….turning that air off stops the flow of gas. It can be turned off for up
to 24 hours without having to do a cold start procedure.
It looks complicated…how many people does it take to operate? The majority
of operation lies on the feedstock preparation; processing feedstock has been
a focus of our efforts recently to increase runtime.
I see a flame in some of the pictures…isn’t this really incineration?
Gasification is 2 step process to first break a biomass material down into
simpler combustible molecules and then combusting this gas. The US EPA
recognizes the difference in the processes and has started updating
regulations with this in mind.
What can the biochar be used for? We are currently investigating what makes
the most sense for our biochar, but it has value as a soil amendment, charcoal
filtration, or as a bio-charcoal.