The Walter B. Hall Resource Recovery Facility
The City of Tulsa has a service agreement with WBH Generating Company, LLC to operate the Walter B. Hall Resource Recovery Facility, also known as the Trash-to-Energy Plant. The agreement includes a requirement that at least 340,000 tons of municipal solid waste be delivered to the plant each year. On days when the trash-to-energy plant gets full, the extra trash is sent to the Quarry Landfill. The Resource Recovery Facility was named for Finance and Revenue Commissioner Walter B. Hall who died while in office in January of 1986.
The Walter B. Hall Resource Recovery Facility began commercial operation in October 1986 with two units. A third unit was added in October 1987 to meet growing demands of the residents and businesses in the Tulsa area. With three units, the plant processes 1,125 tons per day of solid waste, making up to 240,000 pounds per hour of steam. The steam can be used to produce 16.5 megawatts (MW) of electricity that is sold to AEP Public Service Companny of Oklahoma. However, the steam is usually sold to Sun Refining and Marketing Company which is next to the plant. This helps the refinery avoid using oil and other fossil fuels to make its own steam.
Steps to Recycling Waste into Energy
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Trash trucks arrive at the plant. They are weighed at the scalehouse and checked for safety. Once cleared, they enter the tipping building and dump their trash into the storage pit.
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An overhead crane mixes the waste in the pit and lifts the waste up into a feed chute that leads to the furnace.
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From the feed chute, the waste is pushed onto a grate inside the furnace. The grate is sloped downward to let the trash slide down as it starts to burn. The temperature inside the furnace is greater than 1,800 degrees F.
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The heat from the combustion process converts water to steam. A superheater heats the steam further before it is sent to a turbine generator to produce electricity.
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After passing through the boiler sections, the hot combustion gases are used to preheat boiler feedwater in the economizer.
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From the boiler, the cooled gases enter the air pollution control system. The equipment includes a dry scrubber and baghouse.
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The bottom ash slowly makes its way to the end of the grate where it falls into a trough filled with water where the ash is cooled.
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State and federal agencies regulate both the air and the ash that leave the plant. All aspects of the plant’s operation are watched from a control room that is staffed all the time.
Glossary
Source: Integrated Waste Services Association (http://www.wte.org/education/glossary.html)
Baghouse. An emission control device that consists of an array of fabric filters through which flue gases pass. Particles are trapped and thus prevented from passing into the atmosphere.
Bottom ash. A relatively coarse, noncombustible residue of combustion that accumulates on the floor or “grate” of a furnace.
Combustion. The process by which municipal solid waste is burned in a waste-to-energy plant.
Emissions. Gases released into the atmosphere.
Megawatt (MW). A unit of electric power equal to one million watts, or 1,000 kilowatts.
Municipal solid waste (MSW). All solid waste generated in an area except industrial and agricultural wastes, typically from residences, commercial or retail establishments. Sometimes includes construction and demolition debris and other special wastes that may enter the municipal waste stream.
Resource recovery. A synonym of waste-to-energy, resource recovery is the extraction and utilization of materials and energy from wastes.
Scrubber. An emission control device, used primarily to control acid gases, but also to remove some heavy metals.