Farm Waste for Fuel Tanks

Scientists are always on the lookout for better ways to use clean sources of energy. One alternative is natural gas, a domestically produced, plentiful, and clean-burning fuel. The biggest challenge for natural gas researchers has been meeting the 180-to-1 storage-to-volume target set by the U.S. Department of Energy (D.E.) in 2000. Using corncob waste as a starting material, researchers at the created carbon briquettes with complex nanopores, that should meet the D.E.'s storage goal. Current natural gas vehicles are equipped with bulky, high-pressure (compressed to 3,600 psi) tanks that take up the space of a trunk of a car. This new technology enables natural gas to be stored in smaller, low-pressure (500 psi -- the same pressure found in natural gas pipelines) tanks that can be shaped into a rectangular form and mounted under the floor of a car. The researchers discovered that fractal pore spaces (spaces created by repetition of similar patterns at different scales) efficiently store natural gas. "This is the first time carbon storage materials have been made from corncobs, an abundant waste product in the Midwest," says one researcher. "The state of Missouri alone could supply the raw material for more than 10 million cars per year." A test pickup truck, part of a fleet of more than 200 natural gas vehicles, has been in use since mid-October. Researchers are monitoring mileage range per fill-up, pressure and temperature of the tank during charging/discharging, charging/discharging rates under various fueling/driving conditions, and longevity of the carbon briquettes. The work could hold promise for hydrogen storage. Natural gas is one of the cleanest burning alternative fuels available. Most natural gas used in the U.S. is produced domestically. Natural gas is cheaper than gasoline and diesel on an energy-equivalent basis. Natural gas can be produced from renewable sources like landfills. Natural-gas