Colorado Project Generates Methane Gas, Then Electricity, From Food Waste

Landfills are piled high with rotting food that emits methane gas. But a Colorado project is turning the methane gas produced by cattle dung and discarded food into electricity. The Heartland Biogas Project uses six holding tanks to store 1.7 million gallons of either food waste or manure slurry. “Digesters” turn the mess into a water-based sludge, some of which becomes compost. But the more interesting byproduct is methane gas, produced by anaerobic digestion of spoiled milk, old pet food and vats of grease mixed with beneficial bacteria. The gas is transported to an interstate pipeline and used to make electricity. Several problems are tackled in the process: putting a greenhouse gas to work generating renewable energy; diverting food waste from landfills, reducing harmful emissions; and creating jobs.