September 14, 2020 | AD & Biogas, Business+Finance, Facilities

Wisconsin Dairy Digesters Produce RNG

Developers and distributors of renewable natural gas (RNG) have been partnering with dairies in a number of states to convert existing biogas digesters to RNG production. Most recently, U.S. Gain completed installation of gas production equipment at two Wisconsin farms — the Dallmann East River Dairy, LLC in Brillion, and the S&S Jerseyland Dairy, LLC in Sturgeon Bay. U.S. Gain purchased the anaerobic digesters on these farms in 2019, and while the gas upgrading equipment was being installed, it obtained certifications to sell RNG credits via the U.S. EPA’s Renewable Fuel Standard (RINs credits), the California Air Resources Board’s Low Carbon Fuel Standard (LCFS), and the Oregon Department of Environmental Quality’s Clean Fuels program. RNG produced at the farms is compressed and transported to U.S. Gain’s decant facility in Hilbert, Wisconsin that it constructed to expand supply that can be injected into the pipeline.

Digestate produced at Dallmann East River Dairy and S&S Jerseyland Dairy is used as bedding for the cows. Opening photo: Biogas upgrading system at Dallmann East River Dairy. Photos courtesy of U.S. Gain

The company contracted with Nacelle Solutions to coordinate the biogas upgrading system installations at both farms, as well as two other farms  — Holsum Elm Dairy, where the pipeline interconnect is, and Clover Hill Dairy — in U.S. Gain’s RNG portfolio in Wisconsin. Between all four farms, the projects will upgrade a total accumulation of 1,000 standard cubic feet per minute (scfm) of biogas to produce up to 99.5% pure RNG for direct injection into the natural gas pipeline.

In Arizona, construction of the Sunoma Renewable Biofuel Project got underway at Paloma Dairy in Gila Bend. The 10,000-head dairy farm is installing a vendor packaged stirred tank reactor system procured by Montrose Water and Sustainability Services, a division of Montrose Environmental Group, which completed design and engineering for the anaerobic digestion component of the project. The new facility is sized to produce 1.6 million gasoline gallon equivalents (GGE) of vehicle fuel annually for the Class 8 trucking sector — enough fuel to move 10 million miles of freight, according to Fortistar, the project developer. The project will be interconnected with Southwest Gas Company, which will also purchase the gas. The LCFS credits will be sold to Chevron under a long-term agreement.

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