Industrial Environmental Management

Appendix GResource Recovery: Waste‐To‐Energy Facility, City of Spokane, Washington, USA

G.1 Description of the Facility

The source recovery and waste‐to‐energy facility (WTE) located in Spokane, Washington, can process 800 T of municipal solid waste (MSW) daily: there are two boilers rated at 400 T/day each. The facility uses annually about 255 000 T of refuse. There is one steam turbine generators rated 13.8 kV, 30 MVA, 25.8 MW at a power factor of 0.86. The facility's power generation contract varies seasonally from $38 to $48 MWh (gross ~150 000 MW/year) (C. Averyt, personal communication). MSW is typically dumped directly into the refuse pit by truck. The overhead refuse cranes then move the refuse from the pit to each boiler's charging hopper. MSW is mixed and sorted in the pit by the crane operator. The ash residue is produced at a rate of about 6000 T/month. The average refuse‐derived‐fuel composition is given in Table G.1. A schematic diagram of the resource recovery is shown in Figure G.1.

G.1.1 Technology

The Refuse‐Fired Boiler Combustion System is designed to introduce refuse into furnace at a controlled rate and provide the necessary over‐fire and under‐fire combustion air for proper combustion of the refuse and combustible gases. It is also designed to transport the ash inert residue to the Ash Handling System for disposal and to remove the soot and ash particles from the heat transfer surfaces. The combustion air handling portion of the Refuse‐Fired Boiler ...