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Cellulosic Ethanol Better Than Expected |
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Monday, 11 February 2008 |
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Tuesday, January 08, 2008
By Kevin Bullis
There's some more good news
about cellulosic ethanol, a fuel derived from grasses and other nonfood
sources. It's long been estimated that the amount of energy in such
fuels will be much more than the energy required to make them--which is
not the case with corn-grain-based ethanol. Now experimental results are in,
and the ratio of energy produced to energy used is even better than
expected. The renewable energy produced was 540 percent more than the
nonrenewable energy used to make it. Previous studies estimated that
the number would be more like 340 percent. The improvement comes,
basically, from farmers using less energy than researchers thought they
would to grow switchgrass, one of the proposed cellulosic sources.
The better ratio means that cellulosic ethanol could do more to
reduce greenhouse-gas emissions than previously thought. That's
particularly good news, since new legislation will require that some 21
billion gallons of fuel be made from such non-corn-grain sources. The
trick now is to improve methods for converting switchgrass into
ethanol--making the processes cheaper--and to get farmers to start
growing switchgrass in large amounts.
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