It sometimes seems that researchers will try to turn anything into biofuels these days. One new feedstock being tested, in Spain, is the leftover pits from olives after the fruit is pressed into olive oil or, (gasp) de-stoned before being sold to eat. As the pit takes up about a quarter of the total fruit, and some 4 million tons of them are generated each year, the hope is that this waste product can be made into something more useful, like ethanol.
Here’s how the researchers are transforming olive pits into biofuel:
100 Kilograms Olive Waste = 5.7 Kilograms Ethanol
The team pre-treated olive stones using high-pressure hot water (essentially a pressure cooker) then added enzymes which degrade plant matter and generate sugars. The hydrolysate obtained from this process was then fermented with yeasts to produce ethanol. Yields of 5.7kg of ethanol per 100kg of olive stones have been reached. (PhysOrg.com)
As the PhysOrg piece points out, the quantity of olive pits available for ethanol production is small compared to the sum of all the agricultural waste and wood waste in the world, but this research shows that yet another waste product could be repurposed for fuel.
via: PhysOrg.com and Renewable Energy World
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