AT METRO PARK East Sanitary Landfill near Des Moines, Iowa, a 6.4 MW landfill gas-to-energy project is paving the way for a nationwide Waste Management Corp. initiative. Nationwide, Waste Management has more than 60 Caterpillar generator sets running on landfill gas providing more than 48 MW of electricity to utilities.
The Metro Park site is being used to beta test new technologies for use at other installations. With some of the most advanced technology, the facility has logged more than 99 percent up-time, including scheduled maintenance on eight Caterpillar G3516 SITA-LE generator sets.
Each genset is capable of producing 800 kW of continuous power. Since landfill gas can fluctuate from the normal 55 percent methane content, electronic control modules monitor the amount and quality of the intake fuel, optimizing the engines’ performance.
Using advanced methane gathering methods, the landfill produces more than 3.2 million cubic feet of gas per day. An underground piping system spans 5.5 miles, connecting 70 eight-inch diameter well bores drilled to a depth of 86 feet.
The electricity from the site is sold to the local utility, MidAmerican Energy Power, and distributed on the main grid.
The facility burns the equivalent of 112,000 barrels of oil per year in landfill gas. The methane gas, which contributes to ozone depletion when not properly disposed of, is effectively burned off in the Caterpillar engines.
Waste Management has installed more than 60 Caterpillar G3516 SITA-LE generator sets at landfills across the country.