Biobutanol, better than ethanol

Biobutanol, the plant based fuel similar to ethanol, promises more power and less transport headaches. But can it be done cheaply enough?

By Steve Hargreaves, CNNMoney.com staff writer

April 3 2007: 10:37 AM EDT

NEW YORK (CNNMoney.com) -- All of a sudden, everybody hates ethanol.

Among the criticisms: Ethanol takes more energy to produce than it yields ... it can't be easily shipped ... it's driving up the price of food ... it's perverse to put food in fuel tanks while people starve.

Now a partnership between two corporate heavy weights - BP (Charts) and DuPont (Charts) - aims to commercialize Biobutanol, a fuel similar to ethanol but with a few important advantages. The question is: Can they make it cheap enough?

Biobutanol's first advantage: it packs more power. Conventional corn-based ethanol - the kind most widely produced in the United States - is only about 70 percent as efficient as gasoline. This means consumers have to use more of it to drive the same amount of miles.

Biobutanol, on the other hand, is nearly as efficient as gasoline, according to Reese Tisdale, a project consultant at the Cambridge, Massachusetts-based Emerging Energy Research.

Second, biobutanol doesn't absorb water like ethanol does.

So instead of having to be shipped separately and blended with gasoline closer to the filling station, biobutanol could be added to gasoline right at the refiner and shipped via the same pipeline, and share other infrastructure with petroleum-based fuels.

"[Biobutanol] answers a lot of the questions ethanol can't," said Tisdale. "In my mind, it makes more sense."

The production of biobutanol is nearly identical to ethanol. They both ferment a food crop to yield a fuel. The only difference is the enzyme. And like cellulosic ethanol, which can be made using any plant matter, not just food crops - finding the right enzyme at the right price is the trick.

In a recent interview with the magazine Technology Review, BP's biofuels head Philip New said a pilot program to produce biobutanol economically should be running soon - some have speculated this year - with a wider rollout by the end of the decade.

But New was vague about whether a major technological breakthrough was still needed for the fuel to be commercially viable, saying only "Both BP and DuPont are very positive, committed, and optimistic about the prospects of delivering butanol."

A BP spokeswoman, reached by CNNMoney.com, clarified New's comments, saying "BP doesn't believe there will be one major breakthrough, but a number of breakthroughs that can build upon each other and progress the technology."

A spokeswoman for Valero (Charts), the nation's largest independent refiner and a blender of gasoline, said the company had heard of biobutanol but didn't feel it was economical.

Scientists at the government's National Renewable Energy Laboratory are cautiously optimistic, suggesting a breakthrough with the enzyme is still needed.

"It has potential," said Andy Aden, a senior research engineer at NREL. "But it's hard to say what the timeline might be."

Aden said he supported the development of biobutanol simply to diversify the nation's fuel choice as it seeks to use less gasoline, although he said NREL is still counting on cellulosic ethanol to become the main gasoline substitute.

He did say that it's not like ethanol and biobutanol are really competing, as they both use the same feedstock, can be made it the same factory and can be blended together.

While biobutanol may solve the transportation and efficiency problems with ethanol, it still relies on a food crop for its feed stock.

Using corn to make ethanol has caused corn prices to surge, which in turn can push up the prices of other foods that rely on corn - like meat fed with corn meal or soda made with corn syrup.

If a cheap enzyme can be found to make cellulosic ethanol, then it's hoped a similar enzyme can be found to make biobutanol out of wood chips or switch grass as well.

But until then, "It faces the same food-for-fuel questions," said Tisdale, "and that's definitely a big thing."