Wednesday, August 26, 2009

Butanol Advance

Butanol is the simplest alcohol and is nearly equivalent to gasoline in terms of energy density. It is also a lot less hydroscopic, allowing it to be blended with other fuels and then shipped by pipeline. This is not possible with ethanol for that reason driving corrosion. Ethanol’s energy density is only two thirds that of gasoline while butanolis in the plus eighties.

The problem of course is biological yield. Ethanol will work up to nearly 120 plus gram per litre while this product does 15. Thus an increase to 30 is welcome and impacts the economics hugely.

Of course, both brewing processes need a marvelous unique way to preferentially separate out the product in a continuous manner that wastes little energy. We can all dream.

It might be possible to brew both at the same time and then extract a natural blend that may then be adjusted to spec. That would lift the combined yield and possibly make it easier to concentrate since specific separation becomes unnecessary.

In the event, butanol will continue to resist exploitation, but its value as a convincing alternative replacement for gasoline will drive research.

Researchers Boost Production Of Biofuel That Could Replace Gasoline

by Staff Writers
Columbus OH (SPX) Aug 24, 2009

Engineers at Ohio State University have found a way to double the production of the biofuel butanol, which might someday replace gasoline in automobiles. The process improves on the conventional method for brewing butanol in a bacterial fermentation tank.

Normally, bacteria could only produce a certain amount of butanol - perhaps 15 grams of the
chemical for every liter of water in the tank - before the tank would become too toxic for the bacteria to survive, explained Shang-Tian Yang, professor of chemical and biomolecular engineering at Ohio State.

Yang and his colleagues developed a mutant strain of the bacterium Clostridium beijerinckii in a bioreactor containing bundles of polyester
fibers. In that environment, the mutant bacteria produced up to 30 grams of butanol per liter.

The researchers reported their results at the American Chemical Society meeting Wednesday in Washington, DC.

Right now, butanol is mainly used as a solvent, or in industrial processes that make other chemicals. But experts believe that this form of alcohol holds potential as a biofuel.

Once developed as a fuel, butanol could potentially be used in conventional automobiles in place of gasoline, while producing more energy than another alternative fuel, ethanol.

Yang said that this use of his patented fibrous-bed bioreactor would ultimately save money.

"Today, the recovery and purification of butanol account for about 40 percent 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 $3.00 - 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.

This research is funded by the Ohio Department of Development.

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