- Category: Bioenergy
26 Aug 2009
- Published on Wednesday, 26 August 2009 07:51
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Professor of chemical and biomolecular engineering at
Shang-Tian Yang and his colleagues at the university have developed a mutant strain of the bacterium. Photo from the Ohio State University
Engineers at Ohio State University have found a way to double the production of the biofuel butanol using a new strain of bacteria.
Butanol for fuel is currently produced by brewing it in a bacterial fermentation tank. Normally, bacteria can only produce a certain amount of butanol before the tank will become too toxic for the bacteria to survive.
Professor of chemical and biomolecular engineering at Shang-Tian Yang and his colleagues at the university have developed a mutant strain of the bacterium Clostridium beijerinckii which they used in a bioreactor containing bundles of polyester fibers.
In contrast to the 15 or so grams of butanol per liter of water with ordinary bacteria, the mutant strain produced up to 30 grams of butanol per liter.
“Today, the recovery and purification of butanol account for about 40% of the total production cost,” explained Yang. “Because we are able to create butanol at higher concentrations, we believe we can lower those recovery and purification costs and make biofuel production more economical.”
Currently, a gallon of butanol costs approximately US $3—a little more than the current price for a gallon of gasoline.
The engineers are applying for a patent on the mutant bacterium and the butanol production methodology, and will work with industry to develop the technology.
Butanol is a 4-carbon alcohol that is considered a potential biofuel when produced from biomass feedstocks. Like ethanol, biobutanol is a liquid alcohol fuel that can be used in today’s gasoline-powered internal combustion engines.
Biobutanol can be blended with gasoline and ethanol and is said to be capable of improving the blending of ethanol with gasoline. The energy content of biobutanol is only 10-20% lower than regular gasoline.
Currently, under US environmental regulations, biobutanol can be blended with gasoline in concentrations up to 11.5% by volume. Blends of 85% or more with gasoline are required to qualify as an alternative fuel.
ButylFuel, LLC is one of the first producers of biobutanol in the US using an Energy department Small Business Technology Transfer grant to develop a process aimed at making production economical. They are planning to market it as a solvent first before marketing it as a fuel.
Meanwhile, DuPont and BP are making biobutanol the first product of their joint effort to develop, produce and market next-generation biofuels.
- Katrice R. Jalbuena