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News Anaerobic Digestion Biogas Energy Sustainability
Biogas upgrading facility nets $4.1 million grant

February 4, 2020  by Manure Manager

California biotech company Aemetis has been awarded a $4.1 million grant from the California Energy Commission (CEC) to construct a biogas upgrading facility.

The new facility will convert dairy biogas to renewable natural gas (RNG) as a final processing step after biogas is delivered via pipeline. The company is building more than a dozen anaerobic digesters at local dairies in Stanislaus and Merced Counties in California, with plans to expand in the future.

The Aemetis Central Dairy Digester and Pipeline Project is designed to capture methane emitted from dairy manure lagoons, pre-treat the biogas to remove harmful components, then transport the methane from each dairy to a biogas upgrading facility at the Aemetis Keyes ethanol plant.

Once the biogas has been upgraded to utility pipeline-quality RNG, it will be used at the Keyes facility to replace petroleum natural gas that is currently used to power the plant. It may also be injected into the Pacific Gas and Electric Company’s pipeline to be used as transport fuel by trucking firms and bus fleets.


Due to the large volume of truck traffic at the Keyes ethanol plant for biofuel and dairy feed deliveries, Aemetis also expects to supply local trucking fleets through an onsite renewable compressed natural gas dispenser.

“This biogas-to-RNG project adds revenue to dairies while also avoiding penalties from methane emissions that may otherwise become a new cost burden on dairy owners,” Eric McAffee, chairman and CEO of Aemetis, said. “We appreciate the CEC’s strong support for [the project], which we believe will have a direct positive impact on the economic and environmental health of California’s Central Valley.”

Construction is expected to be complete and operation of its first two dairy digesters, the onsite dairy biogas pre-treatment units, a four-mile pipeline and a new biogas boiler at the Keyes plant is set to begin in the second quarter of 2020. The CEC has contributed a total of approximately $18 million grants to support the project and for carbon reduction energy efficiency upgrades to its Keyes plant.


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