Turning Waste to Energy
Waste-to-energy is the process of burning waste to produce electricity. A waste-to-energy facility (WTE) takes in municipal solid waste, puts it through a combustion process and generates electricity to be used within its own community. According to the Florida Department of Environmental Protection (FDEP) "Florida has grown from having one small WTE plant in 1982 to 11 operating facilities as of 2011. [And}, Florida has established the largest capacity to burn MSW of any state in the country."
WTE standards can be found in the Florida Administrative Code, Chapter 62-702.
There are two waste-to-energy plants in Broward County capable of processing 4,500 tons of waste per day. The City of Fort Lauderdale's municipal solid waste (garbage) is processed at these facilities where it is used to produce electricity.
How Does it Work?
Garbage is collected and the trucks bring it directly to the WTE plants. The trucks are weighed, and the contents are tipped into a concrete storage pit. The entire process takes place indoors to control dust from entering the atmosphere, and to ensure that odors are not apparent to the surrounding community. Giant cranes move and mix the waste, and extract bulky items that are too large for the furnace. The cranes then feed the waste into the furnace, which burns at over 1800 degrees Fahrenheit.
The waste moves along a conveyor system of metal grates. Gas produced from the combustion are carried up from the grates through boiler tubes to produce steam. The gas goes from the boiler to a scrubber where they are mixed with a mist of water and lime. As it cools, the gas undergoes a chemical reaction which neutralizes acids and produces particles that can be collected by a "baghouse" filtering system. Finally, the cleaned gas is vented through a stack that rises 200 feet above the ground.
The ash that is a by-product of the WTE process is trolled for metals that can be recycled. The remaining ash is landfilled in special areas called monofills. Like other landfills, monofills have liners to prevent groundwater contamination, and the liquid captured is either used inside the WTE plant or sent for sewage treatment.
More Information
The U.S. EPA offers a range of information about WTE. Visit their Basic Information webpage to learn about the history and economics of WTE and to get more information about how it works and how it is regulated in the United States. There are 86 WTE facilities in the United States with the capacity to generate over 2,700 megawatts of electricity per year from 28 millions tons of waste. To locate Florida's WTE facilities and learn more about the process and regulations, visit the EPA's WTE directory webpage.