The retailer uses an anaerobic digester to convert unsold bio products into electricity.
Ralphs and Food 4 Less, with the support of their parent company Kroger Co., have teamed up with clean technology company FEED Resource Recovery Inc. to convert food that can’t be sold or donated into energy to help power the Ralphs and Food 4 Less distribution center in Compton.
FEED designed and currently operates an anaerobic conversion system for Kroger at the retailer’s distribution facility in Compton, California.
The unsold food from the stores are collected into sanitary containers and fed into a blending system. The blending system removes the inorganic materials like metal and glass. Wastewater from a nearby creamery is heated up and passed into the blending system to create what FEED calls an ‘organic milkshake.’ This milkshake is then introduced into the anaerobic digester, an oxygen-free environment where the organic components are broken down into biogas. Excess water from the digester goes through a purification process. The biogas produced in the digester is sent into two places–the microturbines and the boilers. The boilers produce heat used for the creamery and leftover materials from the digester are turned into fertilizer.
Kroger’s recovery system reduces the company’s waste by 150 tons a day and produces 13 million kilowatt-hours of electricity, which can power up to 2,000 homes in a given period. The system processes over 300,000 pounds of organic materials per day and eliminates over 500,000 diesel truck miles annually. The clean energy produced from the system offsets around 20% of the energy consumption of Kroger’s Compton distribution center.
You can watch a video about the project via the FEED website.