CASE STUDY 1 – Downdraft Gasification

CASE STUDY:  Commercial Waste-To-Energy Plant


SUMMARY: The world’s largest downdraft gasifier was commissioned in October 2016 in Lebanon, Tennessee.   

PROBLEM: The city of Lebanon, Tennessee, wanted to find a new way of waste disposal that would eliminate landfill trips and expenses and improve its sustainability footprint.

APPROACH: Aries Clean Energy developed the ACE DDLF-2000 (64T/day) downdraft gasification system on one acre in Lebanon, Tennessee, that operates on the following specifications:

  • Input Materials: Waste wood is cut to 1- to 3-inch size; sludge is blended with wood before gasification.
  • Process: Syngas produced (85% by volume input) is combusted in an industrial thermal oxidizer (an emissions control device). Thermal energy is transferred to heat water, which drives three Organic Rankine Cylinder generators with a total output capacity of 420 Kw per day that offsets the electrical usage at the wastewater treatment plant next door.
  • Output: 15% of input results in biochar that is 70% carbon and recyclable.

RESULTS: The Aries Clean Energy downdraft gasification system yields waste, energy, and emissions benefits for Lebanon, Tennessee:

  • Waste: More than 16 million pounds diverted from landfills each year
  • Energy: More than 36 MW-hrs generated over the 20 year life of the project
  • Emissions: More than 5,000 pounds of carbon emissions averted annually