Using food waste to create alternative fuel is old news at this point, but a San Francisco company is changing the game.
South San Francisco Scavenger Company is the first in the U.S. to turn food waste into compressed natural gas (CNG). They use a technique called anaerobic digestion. Most anaerobic digesters turn organic matter into methane, but Scavenger Company uses dry anaerobig digestion to produce CNG, which burns cleaner.
The company, along with partners Blue Line Transfer, collect compost in the south San Francisco area, and now they’ll be able to power its fleet of trucks using the food waste that they collect. Company president Doug Button is proud of what he called “a truly closed loop system” for turning waste into alternative fuel.
Our sister site Sustainablog reports that “the Blue Line Transfer anaerobic digester produces up to 500 diesel gallon equivalents (DGE) each day of carbon negative, renewable CNG.” Even better? The byproduct of this process creates something called “digestate,” which can be used as certified organic compost.
Harvesting natural gas to create conventional CNG involves harmful chemicals that pollute drinking water. Creating CNG from food waste means relying less on dirty natural gas to power CNG vehicles.
Scavenger Company projects that they’ll be able to turn 11,200 tons of food waste and paper food packaging into alternative fuel every single year.
What struck me about the program is that not only are they able to use food waste, but they can turn food-soiled paper into alternative fuel. That’s huge. Paper that’s soaked with grease from food isn’t recyclable, so all of that organic materially tends to end up in the landfill. Some paper waste can go into the compost bin, but packaging like fast food wrappers contains chemicals that you don’t want mixing in with your compost.
