2651 Blackbridge Road York, PA 17406
The York County Resource Recovery Center is a waste-to-energy facility that uses the best available state-of-the-art waste management technology to convert municipal solid waste into a smaller volume of ash and produce electricity. All York County combustible household waste is managed at this facility. Owned by the York County Solid Waste Authority, the Center occupies 22 acres of a 150-acre site located in Manchester Township. Administrative offices, an Education Center, a Yard Waste Transfer Facility, and a Recycle Drop-off Center are also part of this acreage. Manchester Township has a host community agreement with the Authority and receives revenue from the Center in accordance with Pennsylvania’s Act 101.
The Resource Recovery Center has been in operation since 1989. The Authority has a service agreement authorizing Covanta Holding Corporation to maintain and operate the Center through 2035. As a result of outstanding safety efforts the facility has received a “Star” designation from the Occupational Safety and Health Administration (OSHA). The facility is one of 4,000-plus sites in the United States (out of a possible 5.2 million) recognized by OSHA as having achieved Star status. The Authority also has a long-term contract with Metropolitan Edison to purchase the electricity generated by the waste-to- energy technology. Under PA legislation, the York County Resource Recovery Center is designated as a tier II source of alternative energy. This means alternative fuel (garbage)–not a form of fossil fuel–is used in the production of electricity.
The Center operates 24-hours a day, every day of the year and is designed to process 1344 tons of waste per day. The facility processes all of York County’s combustible municipal solid waste and some types of residual (manufacturing) waste. Because the facility is expected to serve York County’s waste management needs well beyond 2015, it also accepts waste from out-of-county to maintain optimum daily operations. As York County-generated waste increases it displaces out-of-county waste.
How The Facility Works
Waste trucks enter the Center and are weighed at the scalehouse. They enter the facility via the “tipping hall” and discharge waste directly onto the tipping hall floor. Waste is inspected and pushed into a waste storage pit with a front-end loader.
An overhead crane transfers the waste from the storage pit to three charging chutes. The crane can pick up three to four tons of garbage in one “grab”. Two alternating hydraulic ram feeders continuously push the garbage from the base of the chute into three combustion units.
The facility uses three independent combustion units to process waste. The combustion units each consist of a hollow, water-cooled steel cylinder measuring 50 feet long and 160 inches in diameter and constructed of alternating water tubes and fins welded between the tubes.
Once the waste enters a unit, it tumbles through the unit as it rotates slowly. Fuel oil is used to start up the combustion process and attain a combustion temperature of at least 1800°F. Once combustion is underway, the fuel oil is shut off and the combustion process sustains itself.
High combustion temperatures help maintain acceptable emissions levels. By using garbage as a fuel to generate electricity (instead of fossil fuel), the equivalent of more than 375,000 barrels of fuel oil are saved each year.
Burning material moves toward the discharge end of the combustion unit where it drops from the rotating unit onto a reciprocating air-cooled grate. From the grate, the burned garbage (now called bottom ash) falls into a water filled trough for cooling. A conveyor removes bottom ash from the trough.
Combustion gases leave the lower end of the combustion unit and enter the radiant furnace section of the boiler where the gases are first cooled. Gases flow from the upper furnace into the convection section of the boiler through screen tubes, superheater, boiler bank and economizer sections of the boiler. The economizer reduces the final exit flue gas temperature by preheating boiler feedwater.
At full capacity, the three boilers produce approximately 360,000 pounds per hour of superheated steam, enough to power 20,000 homes. The steam passes through an extraction-condensing turbine that drives a generator producing 36 to 40 megawatts of continuous electricity. The Center uses approximately five megawatts in-house to operate the facility and the Authority’s Management Center. Met Ed purchases the remainder of the electricity.
Air Pollution Control
After exiting the boilers, flue gases pass through an air pollution control system that removes acid gases particulate matter, and other pollutants. The gases first enter a spray dryer absorber (dry scrubber) where they are sprayed with lime slurry and neutralized. Activated carbon is injected into the gas stream to aid in removal of mercury. The air stream then passes through a fabric-filter baghouse where dust matter is removed.
The cleansed air is released into the atmosphere via the stack that stands 327 feet above ground level. The reacted salts from the dry scrubber and the dust matter (called fly ash) collected in the baghouse are combined with the bottom ash and conveyed to the ash holding area.
As the first facility of its kind in Pennsylvania, the York County Resource Recovery Center operates under the strictest of permits. The Center has a continuous emissions monitoring system that is linked 24 hours a day by computer modem to the Department of Environmental Protection in Harrisburg.
The Authority has an agreement with American Ash Recycling to recycle the metals from the remaining combustion ash. The remaining ash is beneficially reused as alternate daily landfill cover (displacing the use of virgin soil).
By using resource recovery, York County reduces its garbage to ash (90 percent by volume), saves the equivalent of approximately 13 acres of landfill space a year (35 feet deep), generates enough electricity to power 20,000 homes, and beneficially reuses 100 percent of the remaining ash residue.