Tapping into renewable fuel
Rising fuel prices, climate change concerns and a desire to convert municipal waste into a useful resource led Sioux Falls, S.D., to invest in an 11-mile pipeline that delivers landfill gas (LFG) to an ethanol plant owned by POET LLC. The project uses one renewable fuel, LFG, to produce another renewable fuel, ethanol.
Sioux Falls’ 90-acre landfill produces about 2,500 to 3,000 cubic feet per minute (CFM) of LFG, some of which was flared or released into the atmosphere previously. In 2004, the city hired Seattle-based R.W. Beck to determine if using the LFG from its landfill to create a renewable biofuel would be economically viable. It determined that it would be possible to use the LFG for power, and it designed an LFG and leachate extraction system. It also designed a connecting pipeline to transport the LFG to the ethanol facility and provided construction oversight, which included investigating right-of-way concerns and working with the South Dakota Public Utilities Commission to ensure compliance with applicable regional, federal and environmental regulations.
The city’s goal was to successfully manage its waste byproduct and turn it into an ongoing revenue stream. To meet the goal, Sioux Falls negotiated a purchase agreement with POET LLC, whereby methane from the landfill would initially displace 10 percent of the ethanol plant’s natural gas use, increasing to 30 percent in 2025 as additional methane is generated. According to POET, the natural gas displacement will decrease carbon dioxide equivalent emissions at the facility by 26,445 tons during its first full year of operation.
Project: Sioux Falls Landfill Gas-to-Ethanol Project
Jurisdiction: Sioux Falls, S.D.
Agency: Public Works Department
Vendor: Seattle-based R.W. Beck, an SAIC company
Date completed: February 2009
Cost: $4.5 million