Miscanthus grows in thick stands up to 13 feet tall in test plots in Illinois. It does well on marginal land without being fertilized, so using it as a biofuel feedstock instead of corn would eliminate a major source of air and water pollution, Davis said. Nitrous oxide, a byproduct of the fertilizers used on cornfields, "is actually a more potent greenhouse gas than carbon dioxide," she said.
"Both switchgrass and miscanthus are perennial grasses, which means that you don't have to till every year, you don't have to plant every year, so there's much less soil disturbance happening than with corn," Davis said. "And because the root system remains in place year after year, there's more carbon going into the soil."
Several hurdles remain before the transition from corn to cellulosic ethanol production can occur on a commercial scale, the researchers said. Converting the sugars in corn to ethanol is easier than releasing the energy locked in plant stems and leaves.
Currently, one commercial-scale lignocellulose biorefinery is under construction in the U.S. in Florida, the researchers said, and other facilities are in the planning stages. More research must be done to increase the efficiency of the process, the researchers said.
"We know that these grasses are enormously productive; we know the agronomy works; we know the ecology works," DeLucia said. "So the next step is to break down the economic barriers by making an efficient conversion chain from lignocellulosics to ethanol."
DeLucia said most scientists in the field expect this to be achieved within a decade.
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign