Progress Through Collaboration 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!

 This is NOT Incineration.  Converts multiple types of feedstock to a consistent gas  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. The clean conversion of biomass into a combustible fuel gas in an oxygen-starved environment 1941 Adler Diplomat powered with a gasifier

Evaporate moisture from the feedstock Feedstock breaks down to gas and tars 3000 degree F heat layer cracks tars Carbon reforms with steam to create CO and H 2 Rotating Grate shaves biochar layer Residue box for biochar removal Drying Pyrolysis High Heat Reduction Feedstock Grate Residue Air Gas

 Woodchips  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

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

Sludge From Sewer Plant: 2 tons per day utilized rather than trucked to landfill City Wood Waste: 10 tons per day chipped and used as fuel

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.

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.