- Category: Technology
08 Nov 2012
- Published on Thursday, 08 November 2012 09:36
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An old bacterial fermentation process – abandoned as impractical decades ago – has found new favor with scientists who say it’s great for producing renewable diesel fuel.
Chemists and chemical engineers at the University of California, Berkeley have retooled a process discovered nearly 100 years ago by Chaim Weizmann (who was also the first president of Israel) to produce a high-energy, low-emitting transportation fuel.
In 1914, Mr. Weizmann found that the bacterium Clostridium acetobutylicum can be used to ferment sugars into acetone, butanol and ethanol – dubbed the “ABE process.”
Now, the UC Berkeley team is extracting the acetone and butanol from the mixture, to leave only most of the ethanol behind.
They then added another, newly developed catalyst that converted the mixture into long-chain hydrocarbons that resemble those found in diesel.
Tests showed that the fuel created this way burned as efficiently as typical petroleum-based diesel. It can also be blended, like diesel, to suit summer or winter driving conditions.
According to the chemists, the extractive fermentation process uses less than 10 percent of the energy used in conventional distillation measures to separate the ethanol from the other chemicals.
The ABE process was discovered near the start of World War I when it was employed to extract acetone, not ethanol, for making cordite. Cordite is a powder that was used as a replacement for gunpowder. Petroleum soon replaced acetone, however, and the ABE process fell out of favor.
While the renewable fuel’s cost is still higher than those made from fossil fuels, the scientists believe the new fuel can be commercialized within five to 10 years, with the adoption of renewable fuel standards in states like California. – EcoSeed Staff