Landfill Gas Turbines: Biogas to Combined Heat and Power to Biosolids Production

The Milwaukee Metropolitan Sewerage District's 2035 Vision includes the goal to “meet 100% of MMSD's net energy needs with renewable energy sources”, and to “reduce MMSD's carbon footprint by 90% from its 2005 baseline.” The Landfill Gas Turbine Facility is a major step in realizing that vision.The combined heat and power facility uses landfill gas (a green energy source) to provide electricity for operating the Jones Island Water Reclamation Facility (WRF). Exhaust heat from electricity production will be used to help dry wastewater residuals to produce Milorganite®, a dried pelletized fertilizer. The turbine facility is the first to use landfill gas for these applications. The attached rendering shows the major components of the facility: the fuel gas conditioning and compression system, the landfill gas turbines, and the waste heat ductwork that ties into the existing facility.The project includes three 4.8-MW Solar Mercury 50 turbines and associated Enerflex gas conditioning and compression systems. There is space and utility accommodation for two additional turbines with associated gas compression equipment. The photograph shows the completed facility.The landfill gas has been procured under a public private partnership between the District and Veolia Environmental Services—the owner of the landfill at the time of partnership. The landfill gas is compressed and treated for siloxanes, hydrogen sulfide, and moisture removal at the landfill, and piped to the WRF.