Anaerobic digestion system set to be commercially available

The technology was invented at the University of California, Davis and is now licensed to Clean World Partners, a Sacramento-based start-up.

Anaerobic digestion relies on bacteria to break down biodegradable waste material in the absence of oxygen. While anaerobic digestion is not a new technology in itself, operational and material-handling limitations had prevented its commercial adoption.

Unlike most other digesters that primarily treat liquid waste, such as manure from dairy farms and municipal wastewater, the UC Davis high-rate digester technology can convert both liquid and solid waste, including food waste, yard waste, plant residues, paper and cardboard.

The researchers also sought to overcome two key barriers to the widespread use of anaerobic digesters: time and money. The new technology makes such waste-conversion systems replicable, with many components prefabricated; this reduces the time it takes to build them. For example, the Clean World Partners system at ARP went from bare ground to energy production within 90 days and cost about $2m to $3m (£1.2m to £1.8m).