Another Path to Biofuels

Source: By MATTHEW L. WALD, New York Times • Posted: Monday, November 26, 2012

After its water is removed, this algae is destined to excrete biofuels.
SEE AlgaeAfter its water is removed, this algae is destined to excrete biofuels.

Last week I wrote about two companies that are racing to be first in commercial-scale production of motor fuel from nonfood sources. A large group of other companies is pursuing various other strategies, one or two steps behind. One of those companies is planning to use algae.

The company, SEE Algae Technology of Austria, is building a 2.5-acre factory on a sugar plantation near Recife, Brazil, that will use genetically modified algae that can eat carbon dioxide from the sugar. Adding urea and some nutrients, the algae excrete ethanol.

The path to profitability, according to the company, is raising the amount of algae produced per unit of area. Algae grows in ponds, but that turns out to require a lot of space: sunlight does not penetrate more than a couple of inches, so the ponds must have big surfaces. The problem is that the carbon dioxide injected to promote algae growth tends to escape from a big surface.

SEE Algae’s solution is a silo that is 16 feet tall and has a volume of 177 cubic feet. Sunlight is directed all over the inside of the silo by optical fiber technology. Because the light is coming from multiple directions, the hardware can produce algae at a density up to 20 times greater than can be generated on a pond, according to Joachim Grill, the company’s chief executive.

The carbon dioxide source is a small electricity-producing plant that burns the part of the sugar cane that remains after the sugar has been extracted. (Brazilian sugar plantations have a second source of carbon dioxide: sugar is often used to make ethanol, and the yeast that digests the sugar and yields the ethanol also gives off a pure stream of carbon dioxide as well. Still, that carbon dioxide has more value when sold for edible uses like producing carbonated beverages, Dr. Grill said.)

The pilot plant, which is scheduled to be complete in May, will produce about 370,000 gallons of ethanol a year, Dr. Grill said. If it runs as planned, SEE Algae’s customer, Grupo JB, will add 14 more, all the same size. Even that would be small by the standards of commercial oil refineries, but it could turn out to be the first serious commercial production of ethanol from algae.

Using genetically altered algae to make ethanol is one route to biofuels, but SEE Algae has a second route in mind. Ordinary algae develops an oil as it grows, and this can be processed into a diesel substitute. The procedure involves removing the water and adding a solvent, generally hexane, that dissolves the cell wall so that the oil can be purified and processed.

But for the time being, Dr. Grill said, customers who follow that pathway do not bother making fuel from the oil. The reason is that the oil can also be processed into products with a higher profit margin, notably cosmetics and nutritional supplements, including Omega-3. “It’s a big rage,” he said of the latter.

Turning algae into fuel or other chemicals that are now made from oil could have commercial benefits when oil prices are high. But it could also make financial sense in countries that have put a price on carbon dioxide emissions to combat global warming, since the algae consume the carbon and reuse it in their product

(If that product is fuel, the carbon will be released when the ethanol or biodiesel is burned. But environmentally, that is better than releasing carbon that had been sequestered deep underground as oil.)