Operations
Wheelabrator Falls produces electricity by combusting waste, and recycles glass, paper, plastic, aluminum and steel by separating it at an on-site material recovery facility (MRF). Advanced, computerized control systems manned by trained engineers govern all aspects of plant operations, monitoring round-the-clock environmental compliance, furnace and boiler conditions, energy production, and dozens of other key operating parameters.
Wheelabrator Falls operates in full compliance with state and federal environmental regulations. It is an Occupational Health and Safety Administration (OSHA)-designated Voluntary Protection Program (VPP) site, which means it goes beyond mandated health and safety requirements to reach the highest levels of employee health and safety. An internal program called Safety on Purpose focuses attention on safe operation, and provides a forum for employees to share ideas and observations.
How Our Waste-to-Energy Process Works at Wheelabrator Falls
The waste-to-energy part of the operation uses a relatively simple but highly refined and constantly updated combustion process to turn municipal trash into energy. The combustion process reduces the original waste volume by 90 percent. The resulting inert ash is disposed of in lined landfills.
Garbage trucks deliver waste to Wheelabrator Falls after it is picked up at curbside. The trucks are weighed, then enter an enclosed reception area and unload the refuse into a concrete receiving pit. Trucks are randomly selected for extensive inspection for unacceptable waste. Overhead cranes transfer the trash into one of multiple boiler feed hoppers. Inside each boiler, an inclined, reciprocating grate system slowly moves the refuse through the combustion process. The temperatures in the boilers exceed 2,500 degrees Fahrenheit to ensure complete combustion. Air for the combustion is drawn from the enclosed reception area; this maintains a negative pressure in the reception area that prevents the release of odors or dust.
The boilers recover the thermal energy that’s released during combustion and convert water in the boiler tubes into high-pressure steam. The steam powers a turbine generator that produces electricity.
Wheelabrator Falls is equipped with the latest technology for controlling emissions from the combustion process. Spray dryer absorbers - also known as dry scrubbers – control acid gases, heavy metals, and organic pollutants. Fabric filters – or baghouses – collect particles. Selective non-catalytic reduction systems control ozone-forming nitrogen oxides, and activated carbon injection captures mercury and trace organic emissions. Stack emissions are constantly monitored to ensure compliance with state and federal air quality standards. Iron, steel and other scrap metals are separated from the inert ash after the waste is processed and sent to the MRF for recycling.
The Materials Recovery Facility (MRF)
Trucks carrying recyclable paper, glass, plastic, steel and aluminum leave their loads inside the MRF. The recyclables go on a conveyer belt where they go through several steps to separate them into their respective streams, such as an electromagnetic wheel to pull out tin and steel. The MRF can process up to 200 tons of recyclables per day, and currently processes about 30,000 tons per year.
