EarthSpin

Corn, switchgrass, sugar cane, and poplar trees – each has been suggested as potential feedstock options for biofuel production. Using these feedstocks efficiently is hampered by identifying the right bug to break down the plant biomass, locating land to grow these crops, and finding the huge volume of water needed to produce the ethanol. Scientists in the heartland have bypassed plants and moved to an alternate feedstock–algae.

Algae are small single-celled organisms that, like plants on land, capture the energy from the sun and store it as chemical energy during photosynthesis. Unlike plants on land, algae do not have the more complicated biomass that makes corn, switchgrass, and all of the other feedstocks difficult to break down.

The chemical energy captured by algae during photosynthesis is stored in oil. These tiny organisms can generate 15 times more oil per acre than other plant feedstock. It is estimated that one acre of algae could produce up to 10,000 gallons of oil. Shifting from petroleum fuel to an algal-based fuel for ground transportation would require harvest of algae covering an area 15,000 square miles, or half the size of South Carolina

Algae are not picky about where they live either; they survive quite happily in fresh water, salt water, and even contaminated water.

“Actually we wouldn’t have to convert any of our arable land,” said Jim Sears, founder of Solix Biofuels. “We could use desert land to grow this algae. It doesn’t require good soil – just flat land, carbon dioxide, and sunlight.”

This new feedstock option is not without difficulties. Past research on algae biofuels focused on harvesting the algal ‘crop’ to extract the oil. Unfortunately, this process kills the algae, so, a new batch of algae must be grown after each harvest increasing expense and time.

A group of scientists at Ames National Laboratory in Ames, IA and Iowa State University developed a groundbreaking ‘nanofarming’ technology that safely harvests oil from the algae so the pond-based ‘crop’ can keep producing.

Nanofarming is a process where sponge-like nanoparticles are used to soak up the oil from the algae. The process does not harm the algae like other methods reducing both production costs and the production cycle.

Once the algal oil is extracted, it is then mixed with a catalyst to produce a biodiesel that meets the American Society for Testing and Materials standards for biofuel.

Victor Lin, director of Ames Laboratory Chemical and Biological Sciences program, has been leading research on using nanotechnology to dramatically change the production process of biodiesel.

“By combining nanotechnology, chemistry and catalysis, we have been able to find solutions that have not been considered to date,” said Lin.

Identifying the best algae for biofuel production and perfecting the oil extraction process will be the main emphasis of the first and second phases of the project.  Phase three will focus on scaling-up the process in a pilot plant for the large-scale conversion of algae oil to biodiesel.