Environment

Winemaking waste could be raw material for biofuel

Winemaking waste could be raw ...
Mounds of grape marc could be made into litres of biofuel
Mounds of grape marc could be made into litres of biofuel
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Mounds of grape marc could be made into litres of biofuel
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Mounds of grape marc could be made into litres of biofuel

Researchers are already developing methods of making biofuel from cellulosic waste, such as corn stover and wood fibers, offering reduced environmental impact and no competition with food crops. Now, new research is investigating the possibility of turning waste from the winemaking industry into biofuel, not requiring the planting of any new crops.

This alternative is being explored by PhD student Kendall Corbin at the School of Agriculture, Food and Wine at the University of Adelaide, Australia. She analyzed the composition of grape marc, the term used to describe solid leftovers such as skins, seeds and stalks.

The research found that in dry weight, between 31 to 54 percent of grape marc consisted of carbohydrate. Of this total, between 47 and 80 percent was soluble in water.

Corbin looked at cabernet sauvignon and sauvignon blanc grapes. She also investigated how to pre-treat grape marc with acid and enzymes in order to boost efficiency.

Using acids and enzymes, a tonne (1.1 tons) of grape marc could be converted into up to 400 liters (106 US gal) of bioethanol. Without those additives, most of the carbohydrates found in grape marc could be converted directly to ethanol through fermentation, with a yield of up to 270 liters from that same amount. The remaining part could be used as fertilizer or animal feed.

"Using plant biomass for the production of liquid biofuels can be difficult because of it structurally complex nature that is not always easily broken down," says Corbin. "Grape marc is readily available, can be sourced cheaply and is rich in the type of carbohydrates that are easily fermented."

Details of the research are published in the journal Bioresource Technology.

Source: University of Adelaide

6 comments
Robert Walther
Spread across thousands of locations across the entire planet, there are 13,000,000 tons of grape waste each year(2011 est.) At 106 gallons per ton, this is equivalent to between 45 MIllion and 80, million barrels of oil(there are several ways to calculate oil equivalency). This total output is no more than a one day supply of world oil utilization. The total number of vineyards is unknown, but estimates put the number at one million. Actual wineries in the 10's of thousands globally. How would this huge, geographically extended source be collected and processed at a financial and ecologic profit? Some larger vineyards or a collection in close proximity could make a break even impact or better. It is a cute idea, but massive, successful implementation is a logistical and economic nightmare.
Gavin Roe
compost it dig it in, turn it into bricks, fire logs, fish food
Stephen N Russell
Job base for CA Wine Region: Santa Barbara-Napa area alone, Be huge
Robert in Vancouver
No doubt the cost of electricty from grape waste will be 10 times more than normal. So that means the Ontario gov't will waste billions of dollars building grape waste power plants, then selling the power to the USA at a loss. One thing the Ontario gov't is really good at is wasting tax dollars.
DFrancis
Instead of using the waste from the ethanol process as fertiliser or animal feed, could it used in an anaerobic digester to produce methane? After that further process, any remaining waste could be used as feed or fertiliser.
svengali49
In Scotland they're already working on the same deal with the leftovers from distilling Whisky. Very soon my car will get 12 years to the McGallon!!! And my tank will be breathalysed on Tuesday and Saturday nights.