Carbon-di-oxide emissions can be highly reduced if conventional fuels like petrol and diesel are replaced by biofuels that are produced from a fast growing grass. A recent research suggests that Switchgrass could be the next-generation ethanol feedstock, yields about five times more energy than it takes to grow it, making the plant a far more efficient fuel source than corn.
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A team of researchers in the United States has found that switchgrass-derived ethanol produced 540 per cent more energy than was required to produce the fuel.
One acre (0.4 hectares) of the grassland could, on average, deliver 320 gallons of bioethanol, said the researchers.
The whole procedure of growing the crop, making the fuel, and burning it in vehicles emits 94 per cent less amount of planet-warming gases when compared to gasoline.
During the production of crops, energy inputs were required in the form of nitrogen fertilizer, herbicides, diesel and seed production. Since, at present any large-scale biorefinery was not in operation, the team projected how much bioethanol such a plant would be able to produce in order to calculate the net energy gain.
"Right now, the Department of Energy is co-funding the construction of six biorefineries in the US. These plants will be completed around 2010, and will be above the pilot plant scale."
Switchgrass could be the main feedstock for cellulosic ethanol, a new type of substitute fuel made from breaking down the woody bits of plants. It grew naturally across wide swaths of the United States but talks are on to grow switchgrass on marginal crop land using far fewer energy-intensive inputs like fertilizer than corn needs. And since it does not double as a feed crop, it will not lead to higher grain prices.
"Switchgrass is a good crop for marginal crop lands," said Ken Vogel, a co-author of the study, called ‘Net Energy of Cellulosic Ethanol from Switchgrass’. "Corn is still going to be grown to make ethanol; whether it ever takes a chunk of crop land away from corn is all going to come down to economics," said Vogel, a researcher for the U.S. Department of Agriculture.