The design and engineering phase of CR&R’s anaerobic digestion project is in full swing.
The planned facility in Perris, California, is permitted to process over 80,000 tons of organic waste per year in Phase 1 and expandable to process over 300,000 tons per year in 3 additional phases, making it one of the largest anaerobic digestion projects in the U.S.
Expanding on their recycling processes, CR&R will integrate the new plant into their existing operations. Feed for the new system will include green yard waste and food waste which requires a robust, flexible digestion process to ensure efficient biogas production.
Eisenmann’s system is fully automated and continuously monitors and optimizes the digestion environment and feed rate. The CR&R plant features four parallel, primary digesters. Following the pre-processing stage, each individual digester vessel is automatically fed through conveyors and dosing bins. The digesters are equipped with a slow moving horizontal agitator to ensure proper mixing of the feedstock – maximizing exposure to biological colonies and facilitating gas release from the homogenized material. Produced biogas is stored in a flexible, double membrane gas storage roof within the post digester.
The biogas is directed from the post digester to an upgrading unit provided by Greenlane Biogas Ltd. Their upgrading process uses water to make biogas interchangeable with conventional natural gas, allowing CR&R to fuel their fleet of collection vehicles with compressed natural gas (CNG) and to feed excess natural gas into the pipeline distribution system. Overall, the anaerobic digestion plant is projected to generate approx. 1,000,000 Diesel Gallon Equivalent (DGE) of CNG per year.
Published in the July 2014 Edition of American Recycler News