Ethanol, the long-time front-runner among gasoline alternatives, might have to step aside for a new technology from British energy company BP. As early as this spring, gasoline stations in Britain could begin offering butanol, an easily transportable and more energy-efficient substitute to ethanol. It will be distributed as part of a trial period that will determine public response to the new fuel and its marketability.
The process by which butanol is created is very similar to that of ethanol. “[It] is a type of alcohol that’s made by fermenting sugars with microbes, such as bacteria or yeast,” said Popular Science magazine. “Most ethanol is produced from corn, wheat and sugarcane.” It’s important to note the similarities between the two, but the differences are what make butanol a more plausible fuel alternative.
Butanol is a more viable energy source than ethanol in part because of its superior energy density. Philip New, president of BP Biofuels, explains that ethanol only provides about two-thirds the energy density of gasoline compared to the upper 80 percent that butanol provides. This means that one gallon of butanol will provide only 10-15 percent less energy than one gallon of gasoline – a huge achievement in a world that isn’t quick to sacrifice performance for a cleaner environment.
Another considerable benefit is the easy storage of butanol. “It isn’t as corrosive [as ethanol], so we don’t have issues with it at higher concentrations beginning to eat at aluminum or polymer components in fuel systems and dispensing systems,” New said. The inability to store a volatile substance could easily affect its practicality as a gasoline replacement.
Additionally, butanol can be transported using existing gasoline pipes. Water gets in pipes with any fuel system; gasoline and butanol allow the water to settle out of the bottom. Ethanol, however, mixes with the water, causing potential problems with the integrity of the final product. New said the big problem, though, is that if the same fuel line used to transport ethanol is then used for aviation fuel, there is the potential of water contamination of the aviation fuel, which could be a very serious problem.
Although butanol has many advantages over the more commonly known ethanol, it is not flawless. According to Popular Science, butanol is far less-efficient to make than ethanol largely because it is more toxic to the microbes that ferment it. Because of this, every bushel of corn produces less than two percent butanol in comparison to 12 percent ethanol.
This variation in the amount of fuel yielded is bringing the affordability of butanol into question. The less butanol extracted from a particular feedstock, the more resources required to produce a certain quantity of butanol. Technology Review said ethanol relies heavily on government subsidies and questions the affordability of butanol if they do not receive any. In response, New said he is unsure if butanol will need subsidies from the government. He thinks that it is important, however, to change the way subsidies are offered. “A transition away from subsidizing biofuels on the basis of volume towards subsidizing on the basis of energy content would represent a level playing field,” he said. “By subsidizing volume, you’re effectively supporting less-energy-efficient alternatives.” It is a valid point considering the high energy efficiency of butanol as compared to ethanol.
Steps, however, are being taken to improve butanol’s fermentation yields. BP has enlisted the help of chemical company DuPont to help engineer microbes that can better sustain themselves in the fermentation process. According to Popular Science, “John Ranieri, head of biofuels development for DuPont, [said] this will drastically improve butanol’s yield, clearing the way for what is potentially a much more useful fuel.”
Though the primary, short-term goal of butanol use is providing alternative fuel to the automotive industry, it is not limited to that. Boeing has teamed up with Virgin Green Fund, a sub-brand of Richard Branson’s Virgin Group conglomerate, to explore the use of alternative fuels, including butanol blends, in aviation, said Popular Science. With increased efficiency through the work of DuPont, there are better chances that butanol use in aviation could become a reality.
Butanol and ethanol both have significant potential as permanent alternatives to gasoline. Although ethanol has provided an excellent renewable source of energy, butanol promises to be a much more reasonable substitute. Its superiority in energy output far outweighs its issues with low yields from feedstock. Further, the collaboration between BP and DuPont will undoubtedly minimize its production problems. With improved efficiency, butanol might become an important player in the future of biofuel.
John Gerbich is the Staff Writer for IdeaBuyer.com, a marketplace for new technology and products that allows inventors to showcase their intellectual property to consumer product companies, entrepreneurs, retailers, and manufacturers. Visit the site by clicking here > Patents for Sale.