The average American throws away more than 900 pounds of trash every year. Organic waste degrading in landfills produces methane gas – a gas 21 times more potent as a greenhouse gas than carbon dioxide. Although most landfills vent this gas in the atmosphere, some facilities are exploring how to use it to fuel trash haulers and other vehicles. The Department of Energy’s Clean Cities program recognizes the potential of these new facilities to generate sustainable fuel from methane gas and thus is working to support landfill gas projects across the country.
Landfill gas is a type of biogas, a natural gas produced by biological sources rather than fossil fuels. Other biogas sources include animal manure, agricultural wastes, and sewage. A biogas facility first uses a special plumbing system to capture the gas. It then removes a number of contaminants from the gas, including carbon dioxide, nitrogen, and oxygen. Lastly, because vehicles run on either compressed or liquefied natural gas, the facility pressurizes or cools it as needed.
Using landfill gas in vehicles combines the benefits of traditional natural gas with those of renewable fuels. Both fuels reduce petroleum consumption and produce significantly fewer smog-forming emissions than gasoline or diesel. Landfill gas, however, has the major advantage when it comes to greenhouse gas emissions (GHG). Using landfill gas as fuel prevents methane and other greenhouse gases from being vented to the atmosphere. As a result, running a vehicle on landfill gas can significantly reduce emissions from landfills. You can see a video of this process here:
The potential for these projects is enormous. The U.S. population produces 27 billion cubic feet of landfill gas a year. This volume is enough to reduce gasoline use by 121 million gallons annually – the equivalent of 220,000 light-duty cars being removed from the road! An analysis by Argonne National Laboratory reports that there are currently 6,000 inactive landfills that could be tapped. The technology has already achieved success abroad, as more than half of Sweden’s 11,500 natural gas vehicles run on biogas.
Here in the U.S., a few cutting-edge projects are setting an example. One such project is at the Solid Waste Authority of Ohio in Grove City, in cooperation with Clean Cities coalition Clean Fuels Ohio. Using only 8 percent of its biogas, the facility annually produces the equivalent of 250,000 gallons of gas.
To expand and support this technology, DOE awarded American Recovery and Reinvestment Act funding to two different biogas projects. The first project is a landfill gas project at the DeKalb County Seminole Landfill in Atlanta, Georgia. The landfill will have an on-site filling station that will serve 200 fleet and shuttle vehicles. The second – at a dairy farm in Bellingham, Washington – will gather off-gas from manure, purify it, and fuel buses.
These projects and others demonstrate the potential for biogas, and how much we are wasting when landfills vent or burn methane. Although it may not turn garbage into gold, this technology’s ability to replace “black gold” could be even more valuable.