DVO, Inc. recently announced the commissioning of its newest “Two-Stage Linear Vortex™” digester at Prairies Edge Dairy Farms in Fair Oaks, Indiana, replacing the prominent dairy’s outdated CSTR/complete-mix digester and combining its biogas with that generated by the original DVO digester installed in 2008.

“Given the same inputs, our newest DVO digester produces more biogas than our old [upright tanks/complete-mix] digester ever made on a good day, by at least 25%,” says Carl Ramsey, Prairies Edge Operations Manager

The new digester adds 30% capacity to Amp Americas – Renewable Dairy Fuels’ (RDF) original Fair Oaks CNG installation, already noted for achieving the lowest “carbon intensity” (CI) score to-date for an operating dairy biogas-to-CNG installation by the California Air Resources Board. A good CI score is crucial in determining the value of the credits created for the California LCFS program, aimed at reducing the carbon intensity of transportation fuels.

RDF’s Jasper plant, its second and newer dairy-to-CNG installation, is also located in Fair Oaks, Indiana, and combines biogas from a number of adjacent Bos family dairy farms that utilize DVO digesters too. The Jasper facility is 50% larger than RDF’s first operation at Prairies Edge, which has been online since 2011 and was the first dairy biogas-to-transportation fuel project in the country.

Today, both dairy CNG sites represent North America’s largest, and the second largest, operating on-farm CNG installations. The manure from all 38,000 milking cattle is anaerobically digested exclusively by DVO, with the resulting biogas feeding both CNG operations.