AD plant opens in California
In California, a consortium of US companies joined together with state energy officials to launch the Calgren Ethanol Biodigester, which utilises waste from dairy farms to power the production of tens of millions of gallons of ethanol.
The Two-Stage Mixed Plug Flow Digester, designed by DVO of Wisconsin and built by Regenis, is the first California digester to use agricultural waste to create renewable natural gas to power another renewable energy facility.
The process begins with local dairy, Four J Farms, sending its cow manure to the Calgren digester, which captures methane and burns it as clean biogas. According to the American Biogas Council, replacing 10% of California's natural gas supply with renewable gas would reduce greenhouse gas emissions by tens of millions of tonnes annually while cutting wildfire, air pollution and landfilling – issues raised by the California Energy Commission (CEC) when it invested $4.6 million (€4 million)in the project.
'The San Joaquin Valley is challenged with some of country's worst air pollution,' comments Janea 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.'
Currently, California imports over 90% of its natural gas, costing the state thousands of jobs and billions of dollars. In fact, California constructed nearly half of all the new natural gas-fired power plants built in the US in 2013. Renewable natural gas could change that equation by utilising organic waste to power farms, factories and communities.
Regenis VP, Bryan VanLoo, says: 'Our mission is to re-imagine reusable resources. In the case of California, that potential is almost limitless. Utilising digesters would not only create hundreds of new construction and operation jobs in rural communities like Tulare County, but there is enough organic waste to power 2 to 3 million homes or to generate 2.5 billion gallons of clean, ultra-low carbon transportation fuels.'
