New biomass technology dramatically increases ethanol yield from grasses and yard waste

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 yard waste.

"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 agricultural engineering.

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 pretreat biomass.

The technology is available for licensing from the University of Georgia Research Foundation, Inc., which has filed a patent application.

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 ethanol.

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 prices.

"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.

Source: University of Georgia

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Citation: New biomass technology dramatically increases ethanol yield from grasses and yard waste (2008, July 28) retrieved 25 August 2019 from
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Jul 28, 2008
If this process can convert kudzu into ethanol, the South could become the Saudi Arabia of ethanol.

Jul 28, 2008
Unfortunately, the end product is so inefficient. There just isn't enough firepower produced in the burning of ethanol. We might need to see a 100-fold increase over current methods to put a real dent in gasoline. Additionally, ethanol is only priced as it is now because of subsidies. I think a smarter move is algae-based biodiesel which iws readily available now. Diesel engines get 30% better fuel economy than gasoline-based engines . Furthermore, using bluetec technology we can filter out 90% of the particulate polution.

Jul 28, 2008
Biodiesel production produces glycerol which can be converted via certain strains of E. coli to ethanol and/or other more valuable chemicals that are currently created by consuming petroleum. But while ethanol might or might not be the new transportation fuel, (biodiesel may not either) it is still an important industrial chemical and might be used as a non-transportation energy source in some instances.

Jul 28, 2008
Have they indeed not invented a new kind of schnaps?

Jul 28, 2008
whoever pushed for biofuels is an idiot.

Jul 28, 2008
Yes makotech222, lets make blanket statements and forget about reason, logic or anything else including politeness.

Jul 29, 2008
Well i thought i would spare my logic since its common sense practically. Sure lets burn up our food so we can power our cars. put those in poverty even farther away from affordable food. i think their lives are more important than our cars, dont you? There are much more viable means to power our cars, such as electricity or hydrogen. Hopefully mccain gets elected and we can start putting up nuclear reactors (ABOUT FRIKKEN TIME, stupid enviromentalists dont know what they want) and make electricity much cheaper, making it even better as a fuel.

Jul 29, 2008
Why are politics ignoring research like this?

If they're funding research like this they can hardly be said to ignore it.

Producing ethanol from corn is obvious pandering to corn farmers and has very little to do with biofuels. It works and will continue to work only as long as advocating corn ethanol seems to generate more votes from farmers than it loses from everyone else.

Jul 29, 2008
Why are we even putting valuable time and money in this type of technologies?
It's like betting on a cripple horse at a horse track...
Biofuels have NO future. We would need more land than the Earth has to offer us, to meet up to our (growing) fuel demand! Meaning we would have to cut down more forests to clear land for agriculture. These crops will need fresh water, which will put even more stress on the resources we have now. Deforestation will also have a huge impact on biodiversity and will make CO2 levels rise!
The latter is not just because we will have fewer forests, but also because biofuels still emit greenhouse gasses!

So wake up world!!!

If we want to improve our air quality, battle climate change and efficiently use our resources we should let this type of research rest and invest our time and money in electric cars (NO hydrogen fuel cells), solar energy, wind energy and nuclear fusion/fission instead.

Jul 29, 2008
whoever pushed for biofuels is an idiot.


Also /agree with above statement

Jul 30, 2008
^^ true, but hydrogen fuel cells could work as well too? I would rather secure our foods for eating and use alternatives when necessary.

Jul 30, 2008
there will always be a need for fuel on boats because the water is so corrosive to batteries

Couldn't we just make sure that the battery can't get in contact with the water? There already are electric and solar boats which use batteries to store their energy..

^^ true, but hydrogen fuel cells could work as well too?

Hydrogen fuel cells work as a battery (they store energy), but they are less efficient. It also takes energy to create hydrogen. So using hydrogen fuel cells takes two steps, while electric batteries need only one step.

Hydrogen car: Energy > Hydrogen > Fuel cell
Electric car: Energy > Battery

There always is a loss when converting energy (heat, friction). Meaning electric batteries will always have more potential than hydrogen fuel cells. Another plus is that electric cars can use regenerative brakes to reload the battery. So there will be less energy lost when you hit the brakes. Electric vehicles also have less moving parts, so they will produce less sound and break down less often.

Aug 09, 2008
> We would need more land than the Earth has to offer us... These crops will need fresh water, which will put even more stress on the resources we have now.

Both of these statements are inaccurate. Algae and Micro algae used in the production of biofuels can be grown using sea water and/or sewage water. Sea water rich in phosphates in some of the growing dead zones in the ocean could even be used. Algae could be grown and harvested from the ocean.

Also, the production of micro algae can be done in plastic pouches filled with water that actually go up. These algae crops can produce up to 30 times more vegetable oil than the best existing food crops.

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