Commercial Waste-To-Energy Plant

Commercial Waste-To-Energy Plant


Lebanon, Tennessee


October 2016

Customer Name

City of Lebanon, Tennessee


PHG Energy 64-ton-per-day downdraft gasification unit

The local landfill is projected to fill and be closed in the next few years. The city wanted to find a new way of waste disposal that would eliminate landfill trips and expenses.

Time lapse video:  Several months of Lebanon plant construction (compressed to 90 seconds)
The world’s largest downdraft gasifier was commissioned in October 2016 near Nashville in Lebanon, TN. The clean tech energy plant will process up to 64 tons per day of waste and produce up to 420 Kw of electricity. This clean conversion gives Lebanon renewable energy to use to help offset the electric expenses of the city’s wastewater treatment facility. More than 310 people attended the Open House where guests were treated to an on-site tour of the facility. Commercial wood waste that was previously dumped into area landfills will be blended with hundreds of tons of discarded, scrap tires and sewer sludge to provide the fuel for the clean gasification process. The synthetic gas produced in the process is converted to on-site electric power for the wastewater treatment plant’s operations.

Projected Benefits

  • 5,000,000 pounds (2,500 tons) of carbon emissions kept out of the air each year, which equates to the CO2 produced annually to provide electricity to 312 homes, or the annual Greenhouse Gas Emissions from over 450 passenger vehicles.
  • Over 16,000,000 pounds (8,000 tons) of material diverted from landfills each year.
  • System will create beneficial use of over 800,000 pounds (400 tons) of scrap tires each year.
  • Deployment will help both the city and local industries move to zero landfill goals.
  • Will produce 36,000 MW-hrs of power over 20 years (enough for 350 average homes).

The System Details

  • 64-ton/day capacity throughput PHG Energy downdraft gasifier is the core technology
  • Wood and tires are cut to 1” to 3” size; sludge is blended with wood before gasification
  • 30% moisture content of total blend is target.
  • Syngas produced (92% by volume input) is combusted in industrial thermal oxidizer (an emissions control device).
  • Thermal energy is transferred to heat water, and the hot water drives three Organic Rankine Cycle generators with a total output capacity of 420 Kw.
  • 8% of input results in biochar which is 70%carbon and recyclable.
  • All feedstock is locally sourced and prepped by a specialty contractor.
  • Footprint of gasification plant is less than one acre.
  • Commissioned in October 2016.


We're reducing landfill use, creating clean energy and keeping thousands of tons of carbon out of the air each year ... all with a positive cash flow. This is a win.

Bernie Ash, Mayor of Lebanon, TN