The Calgren Ethanol Biodigester is off and digesting waste from dairy farms into ethanol. The ethanol will be used by consumers in California’s Central Valley. The Two-Stage Mixed Plug Flow Digester was designed by DVO, Inc. and built by Regenis. The partners said it is the first California digester to use agricultural waste to create renewable natural gas to power another renewable energy facility, creating a step forward in a virtuous, zero waste lifecycle.
The process begins with local dairy, Four J Farms, sending their cow waste to the Calgren digester, which captures methane and burns it as clean biogas. While Calgren will be utilizing the renewable gas to power its facility, the digester will also greatly reduce bacteria and pathogens so dairy farmers can reuse the liquids (water) safely on their crops.
“I am proud of the contribution that Calgren can make to this incredibly green, low-carbon intensity project,” said Lyle Schlyer, president of Calgren Renewable Fuels. “Digesters are often talked about, but actually building one and getting it into operation doesn’t happen all that often. This is a marriage of industrial and dairy interests.”
The California Energy Commission (CEC) invested $4.6 million in the project. In January 2015, CEC issued rules that could increase the number of digester projects around the state. Today California imports over 90 percent of its natural gas and in 2013 the state constructed nearly half of all the new natural gas-fired power plants built in the U.S. The need to import the energy is fueling the state’s commitment to supporting locally produced alternative forms of power.
“The San Joaquin Valley is challenged with some of country’s worst air pollution,” noted Janea A. Scott, Commissioner at the CEC. “The Pixley Biogas anaerobic digester is the first anaerobic digester on a California farm permitted to use all feedstocks, including municipal green waste and food processing waste. This type of innovative technology helps California meet its clean air, petroleum reduction, and climate goals.”