DTE Biomass Energy launches three projects in 2008

By Susanne Retka Schill
Residents of Bellefontaine, Ohio, have started using electricity generated by their own trash via a landfill gas project built and operated by DTE Biomass Energy, a subsidiary of Michigan-based utility DTE Energy Co. The Ohio project, with a 4.8-megawatt generating capacity, was the third in the past year built by DTE Biomass Energy. A 1.6-megawatt landfill-gas-to-energy facility in Denton, Texas, started generating power in December, and a 3.2-megawatt plant in Statesville, N.C., started up in mid-2008. DTE now has 22 projects in 13 states.

DTE Vice President of Business Development Rick DiGia said interest in landfill-gas-to-energy projects is steadily growing as a result of the renewable power standards taking effect in several states. In addition, since 1998, the U.S. EPA has required landfills meeting certain criteria to capture their landfill gas emissions.

DTE's first installation in Riverview, Mich., celebrated its 20th year in operation in 2008. The original wells are still producing small amounts of gas at the active landfill, DiGia said, although new wells have been added over the years as the landfill expanded. Where there is sufficient rainfall, new landfills begin generating gas within a year for a lifespan of approximately 10 years. In dry areas, such as Arizona, it may be five to six years before gas is generated, and the gas production continues for approximately 20 years.

"People think landfill gas is free," DiGia said. "Generally speaking, to sink a well and connect it to a collection system costs $20,000 per well." DTE uses standard compression, filtering and cooling technology to clean up landfill gas for three main products. For electrical generation, the gas is cleaned up and burned in a generator or turbine. For industrial applications, plant boilers are converted from natural gas or coal to utilize the landfill gas, which is a mixture of roughly equal parts of methane and carbon dioxide. The third application requires more complex technology to separate the carbon dioxide and other components to produce a pipeline-grade methane gas.