Report ‘Lowering Costs of Food Waste Co-digestion for Renewable Biogas Production’ Prepared for California’s Energy Research and Development Division
October 19, 2020 — A final report for the California Energy Commission’s Lowering Food Waste Codigestion Costs project has been published in October, 2020. This report is based on a three-year research completed in 2019 by Kennedy Jenks.
This report was based on demonstration study to evaluate a new technology to lower the pre-processing cost of food wastes and a new strategy to add fats, oil, and grease and pre-processed food wastes for anaerobic digestion with wastewater sludge (co-digestion.) These two steps aim to lower overall cost of co-digestion and lower dewatered cake requiring disposal, which, in turn, will encourage the diversion of food waste from landfills and enhance production of digester gas, a renewable energy source.
Lead author Ganesh Rajagopalan notes that ‘This study showed that preprocessing of food wastes using the organic extrusion press results in up to 54% cost savings compared to conventional techniques, along with an estimated $8.9 to $9.3 million worth of energy savings for a 100-million-gallons-per-day treatment plant.’ Additional Kennedy Jenks contributors were Bhargavi Subramanian, Ph.D., Helia Safaee and Ryan Holloway, Ph.D., PE.
The project was performed at Silicon Valley Clean Water, Redwood City, CA. In addition to the Kennedy Jenks leadership team, project support was provided by Silicon Valley Clean Water, San Francisco Recology, Bay Area Air Quality Management District, CalRecycle and the County of San Mateo. The authors also wish to thank Abolghasem Edalati, Jonah Steinbuck, Laurie ten Hope and Drew Bohan of the California Energy Commission.
The report, Lowering Costs of Food Waste Codigestion for Renewable Biogas Production (EGRO 945, EPC-14-046), is available here.