Green Slime Slides into Biofuels Arena: How Algal Biofuels May Be the Next Alternative

By Seanica Reineke

Despite skepticism from biofuels critics, a University of Nebraska-Lincoln researcher and associate professor of biochemistry believes as more research is applied, advanced biofuels will continue to develop- and at a faster pace.

"It is in our nation's interest to invest in that committed research to allow our country to be oil independent so that political upheavals in the Mideast or offshore oil rigs in the Gulf of Mexico, while they are going to be a factor far into the future, don't have as much potential to upset our economy and national security as they do now. That requires investments that may take five, 10, 20 years to reach their fruition; but without them, we don't have any chance of avoiding the catastrophes that greater dependence on oil will bring," said Dr. George Oyler.

Algal biofuels research is quickly expanding, and the University of Nebraska-Lincoln has become a research hub for this type of biofuels, involving between 12 and 16 principal

Dr. George Oyler

investigators and funding from the United States Department of Energy and the National Science Foundation. Oyler, UNL algae research facilitator, calls the University of Nebraska "a haven for world-class algae research," adding that although it makes up a small portion of the national and international efforts in algal biofuels, UNL holds a "prominent position in those groups."

"It was a little unexpected when I entered algae to find, in the heartland of the United States, such a successful group of researchers involved in something that grows in water," said Oyler, "but as it turns out, this is an excellent place to be addressing the problems of our bioenergy needs through algae." He said UNL already is a major contributor of energy necessary to support the world population through agriculture, including ethanol production, and believes the state is well-positioned in the food and energy sectors to help advance the nation's goals.

How is Algae Different from Other Advanced Biofuels?
Algae brings to mind green pond scum on top of water, but this research uses a fast-growing microalgae. Oyler said microalgae are capable of growing 10 times faster than earthly plants on a per-acre basis. Oil can make up 30 to 50 percent of algae's weight, compared to just 15 or 20 percent oil from a soybean, Oyler said. This means algae has the potential to produce more oil than crops traditionally grown for biodiesel. Even though ethanol has been successful, it can't replace all oil uses completely, such as jet fuels, but algae can replace those uses. "The potential's there to make much more fuel per acre with algae," Oyler said.

With the right systems in place to allow algae to reach just half of its maximum production capabilities, Oyler said the United States' requirements for transportation oils could be replaced with algae using 1/20th of the acreage necessary with ethanol. One example of an efficient algae oil production system includes a photo bioreactor, which is a self-contained device providing a controlled environment for algae to grow. Oyler said it can be as simple as plastic enclosed clear tubes, but the system is very expensive.

Another approach to growing algae is in raceway ponds, which are open ponds shaped like ovals, that are stirred with paddlewheels. However, with the raceway ponds being open- not enclosed, like the photo bioreactor- the algae is exposed to the environment and can become contaminated from outside elements.

Beside issues of appropriate systems for growth, there are other factors slowing the advancement of algal biofuels.

Challenges Confronting Algal Biofuel Production
Cost is the biggest barrier to expanding production of algal biofuels, Oyler said. Not only are costs high for setting up systems to grow algae, but so is the cost of a barrel of algae oil. In the mid 1990s, researchers estimated algae oil could be made at $60 to $80 per barrel. Now, the estimated cost per barrel of algae oil is at least $300. Oyler said the current research will lower that price, though it may take five years or more to happen. Even so, he said algae will represent a "substantial contribution to the biofuels mix."

Another challenge is how to harvest algae and extract the oil. Currently, once algae reach a certain density, water must be removed from it. Then, once the algae become a certain consistency, like that of a semi-solid paste, the oil must be extracted. Oyler said "one of the biggest breakthroughs in the future will come when the algae actually secrete the oil or other biofuels right into the liquid media." Then, theoretically, he said the oil could be skimmed from the top of the water and converted, solving the problem of efficiently harvesting and extracting the oil.

Still another issue is the fact that algae uses sunlight and removes carbon dioxide from the air. Oyler said high-productivity systems are necessary to allow algae to reach its full potential, which would also reuse carbon dioxide, not waste it. He said algae can be grown on under-utilized land and can use water in a way that doesn't compete with other agricultural uses. "All the way around, algae can benefit the ecosystem and reduce the nation's energy security issues," Oyler said. It has taken thousands of years in agriculture and agronomy development for other crops, but that spread of time cannot be taken with algae, according to Oyler.

"We need to compress those thousands of years of technology advancements and farming achievements into a decade or so with the algae," said Oyler. "It's doable. It will require resources. We're well-suited to do that here in Nebraska along with other universities and companies throughout the United States," he said.

Bright Future for Algae
In the future, Oyler expects to see biotechnology and bioenergy develop quickly, much like medical applications of biotechnology in the 1980s and 1990s which resulted from research with the National Institute of Health. That growth won't be limited just to biotechnology, Oyler said. "It will be engineering, nanotechnology, genetic modification, a whole range of issues that will allow us to address bioenergy issues." Both the opportunities and challenges are great in scale, he said, but they are also exciting.

The future may also include steps in one of Oyler's research goals: how to develop an integrated system in Nebraska that works, incorporating algae and animal waste. Cattle waste would be used in anaerobic digestion fluids, which are alternative solutions to livestock waste management. The waste would then be used to fertilize the algae, which would be used not only for biofuels, but also for animal feed and proteins and chemicals for various biotechnologies. "This provides an integrated system between animal agriculture, bioenergy from the anaerobic digestion to algae and how to use algae most beneficially in Nebraska," Oyler said.