At Ralphs, one of the oldest and largest supermarket chains on the West Coast, it helps keep the power on.
In a sprawling Compton distribution center that the company shares with its fellow Kroger Co. subsidiary Food 4 Less, organic matter otherwise destined for a landfill is rerouted instead into the facility's energy grid. Though many grocery stores have tried to cut down on food waste and experiment with alternative energy, Kroger says it's the first supermarket company in the country to do both simultaneously.
The technology that helps transform moldy chicken and stale bread into clean electricity is known as an anaerobic digester system. At the 59-acre Compton site, which serves 359 Southern California stores, more than 100 onlookers gathered Wednesday to watch the system go to work.
Several chest-high trash bins containing a feast of limp waffles, wilting flowers, bruised mangoes and plastic-wrapped steak sat in an airy space laced with piping. Stores send food unable to be donated or sold to the facility, where it is dumped into a massive grinder — cardboard and plastic packaging included.
After being pulverized, the mass is sent to a pulping machine, which filters out inorganic materials such as glass and metal and mixes in hot wastewater from a nearby dairy creamery to create a sludgy substance.
Mike Vriens, Ralphs vice president of industrial engineering, describes the goop as a "juicy milkshake" of trash.
From there, the mulch is piped into a 250,000-gallon staging tank before being steadily fed into a 2-million-gallon silo. The contraption essentially functions as a multi-story stomach.
by Tiffany Hsu, LA Times | Read more:
Image: Christina House, For The Times
