ScienceDaily (July 29, 2008) ??? University of Georgia researchers
have developed a new technology that promises to dramatically
increase the yield of ethanol from readily available non-food
crops, such as Bermudagrass, switchgrass, Napiergrass???and even
???Producing ethanol from renewable biomass sources such as
grasses is desirable because they are potentially available in
large quantities,??? said Joy Peterson, professor of microbiology
and chair of UGA???s Bioenergy Task Force. ???Optimizing the
breakdown of the plant fibers is critical to production of liquid
transportation fuel via fermentation.??? Peterson developed the
new technology with former UGA microbiology student Sarah Kate
Brandon, and Mark Eiteman, professor of biological and
The new technology features a fast, mild, acid-free pretreatment
process that increases by at least 10 times the amount of simple
sugars released from inexpensive biomass for conversion to
ethanol. The technology effectively eliminates the use of
expensive and environmentally unsafe chemicals currently used to
The technology is available for licensing from the University of
Georgia Research Foundation, Inc., which has filed a patent
Inexpensive waste products???including corn stover or bagasse, the
waste from corn and sugar cane harvests, fast-growing weeds???and
non-food crops grown for biofuel, such as switchgrass, Napiergrass
and Bermudagrass, are widely viewed as the best sustainable
resources for ethanol made from biofuels.
???Using non-food crops that can be grown on marginal lands, like
grasses, and fibrous waste streams like corn stover, is important
because of the ongoing food-versus-fuel debate,??? said Peterson.
???When agricultural crops, such as corn or potatoes, are grown
for biofuels production, the cost of the starting material may
fluctuate greatly because of competing demands for food and feed.
The trade-off with using a biomass like grasses is that grasses
are harder to break apart than corn or potatoes, and the cost of
making the same fuel, like ethanol, rises.???
Developing an efficient, cost-effective process to convert the
fibrous stalks, leaves, and blades of plant wastes into simple
sugars is the biggest challenge to bio-based ethanol production.
Thick, complex plant cell walls are highly resistant to efforts to
break them down.
Currently, woody biomass requires soaking under high pressure and
temperatures in expensive, environmentally aggressive bases or
acids before it is subjected to enzymes that digest it, producing
simple sugars. The harsh pretreatment solutions subsequently must
be removed and disposed of safely. They also cause formation of
side products that can slow down the conversion of the sugars into
In contrast, the environmentally friendly UGA technology
eliminates the expense of harsh pretreatment chemicals and their
disposal, and the formation of side products is minimal.
???The new technology has commercial application for the biomass
industry, including producers of sugar cane, corn, switchgrass,
Napiergrass and other woody biomass crops,??? said Gennaro Gama,
UGARF technology manager responsible for licensing this
technology. ???It may also help renewable energy and
biofermentation companies???and local governments.
???By allowing for the use of myriad raw materials, this
technology allows more options for ethanol facilities trying to
meet nearby demand by using locally available, inexpensive
starting materials,??? he added. ???This would greatly reduce the
costs and carbon footprint associated with the delivery of raw
materials to fermentation facilities and the subsequent delivery
of ethanol to points of sale. Local production of ethanol may also
protect specific areas against speculative fluctuations in fuel
???It???s easy to imagine that this easy-to-use, inexpensive
technology could be used by local governments, alone or in
partnership with entrepreneurs, to meet local demand for ethanol,
possibly using yard waste as a substrate,??? he said.