“This facility is going to be a model for waste-to-energy partnerships,” Lebanon Mayor Philip Craighead said last week, “as well as the first stage in moving our city completely away from dumping waste into landfills.”
His remarks were part of a groundbreaking ceremony that kicked off construction of a new gasification plant at the city’s waste water treatment facility, which took place on November 12 in Lebanon. Tens of thousands of tons of sewer sludge, used tires and industrial wood waste will be processed there each year, producing electricity to help power the treatment plant and diverting those materials from area landfills.
PHG Energy of Nashville is designing and building the new facility for Lebanon. The installation will mark the 14th commercial downdraft gasification unit going on line for that company, and will include utilization of the world’s largest downdraft gasification unit with a full capacity throughput of 64 tons per day. Gasification is a clean thermo-chemical process that breaks down biomass-based material in a high-heat and low-oxygen environment. There is no incineration or burning involved in the process. The only residue after production of synthetic fuel gas is a carbon biochar that has multiple agricultural, industrial and direct fuel uses. The syngas is used to power an Organic Rankine Cycle generator which will provide for the gasification operation’s internal needs, and deliver up to 200 Kw directly to the operation of the waste plant.
Tom Doherty, Environmental Specialist with the Tennessee, Department of Environment and Conservation (TDEC), said the new facility is an important step forward in efforts Tennessee and his department are fostering across the state. “When we look at the thousands of tons of wood waste and sludge this plant will cleanly process, that is a tremendous step forward,” Doherty said. “One of the most exciting parts of deploying this technology in Lebanon is that hundreds or tons of scrap tires will be put to beneficial use while saving Wilson County a considerable portion of their previous disposal expense.”
TDEC has awarded the project funding of $250,000 through the Clean Tennessee Energy Grant program, and facilitated a subsidy of 70% of the $3.5 million financing’s interest cost through the Federal Qualified Energy Conservation Bonds program.
Mayor Craighead pointed out that he and his staff had interviewed “many candidates” in the waste-to-energy industry before choosing PHG Energy. “We talked to people who said they could do it, but could not prove it,” Craighead said. “And we talked to people who could do it, but the expense was so high that the financials would never work. What we found with PHG Energy is a local company with a proven technology that will provide a very positive cash flow for the City of Lebanon.”
Fred Burton and Rob Cesternino, Lebanon City Council members who supported the project through its development stages, were on hand for the groundbreaking, as were Tennessee State Senator Mae Beaver and Tennessee State Representative Mark Pody, Wilson County Mayor Randall Hutto, Katy Miller representing U.S. Senator Bob Corker, Cumberland University President Dr. Paul C. Stumb IV, and Pam Crozier, Energy Coordinator, USDA Rural Development.
PHG Energy is a private company owned by a Nashville family that has operated a large regional Caterpillar dealership for 71 years. Over a dozen of the patented downdraft gasification units have been successfully installed since 2007, with two contracted municipal waste-to-energy systems currently in the design/build phase.