Renewable Energy Fuels Dryer, Saves $1 Million

A new biosolids thermal dryer is enabling Manatee County, Florida officials to harvest renewable energy, reduce fuel consumption, produce a revenue-generating product, and ultimately save taxpayers $1 million per year.  

The county is using methane gas, rather than natural gas, to power the $14-million dryer. Methane gas is produced naturally when debris decays, and accounts for about 50 percent of the gas emitted from landfills. Manatee County is capturing the methane gas from its Lena Road Landfill, which sits adjacent to the Southeast Water Reclamation Facility where the dryer is housed.

 “There are lots of thermal dryers in the state of Florida, but they don’t have access to a gas source, so their operating cost is much higher. Manatee County is capturing a free or wasted fuel source and operating cost effectively,” says Street Lee, PE, the McKim & Creed vice president who managed the project.

 Saving money and leveraging a renewable energy source aren’t the only benefits the thermal dryer provides to residents. Drying sludge from the county’s three reclamation facilities: 

-          creates a new revenue stream by producing Class AA biosolids (pellets) that are sold for fertilizer;

-          eliminates the need for trucks to haul sludge to disposal sites, which reduces trucking costs and fuel consumption by 1,250 gallons per year; and

-          cuts diesel consumption by 16,000 gallons per year.

 “The county is definitely reducing its carbon footprint and will see the benefits of a sustainable solution to biosolids management for years to come,” says Lee.

Manatee County, Florida’s $14-million biosolids thermal dryer is located inside this structure at the Southeast Water Reclamation Facility. Manatee County received a Future of the Region Honorable Mention from the Tampa Bay Regional Planning Council for this project.

The dryer produces Class AA biosolids that contain no detectable levels of pathogens and very low metal concentrations, and that meet the most stringent requirements of the EPA’s 503 regulations.

The 4,160 tons of Class AA biosolids (pellets) produced annually from the facility are sold as fertilizer to a bulk purchaser.