Algae Holds Promise as Renewable Fuel — Just Not Yet
For algae to move into commercial production more quickly, the industry needs more start-up financing, and regulatory certainty, such as existing federal renewable fuels standards.
Legislation providing tax credits to the biodiesel industry passed last December, but legislation to broaden the definition of the cellulosic ethanol producer tax credit to include feedstocks like algae didn’t make it.
”The challenge is making sure there are long-term incentives or mandates provided by government and regulatory bodies, and to make sure those don’t change on a yearly basis,” Rekokse said.
One reason Valero’s Diamond Green Diesel project is moving ahead is that the joint venture received a $241-million loan guarantee from the U.S. Department of Agriculture and the Department of Energy, he said.
Another hurdle is cost. Tallow and camelina, the two non-food plant oils available in the highest quantities, cost between $4 and $5 a gallon, he said, while algae costs far more.
One reason Solix is using wastewater to make algae at its demonstration plant is to see if it can help bring the costs down.
“We have a clear road map toward driving down the cost, and each year to show technological improvements and yield improvements,” Money says.
Butanol from algae
Another strategy for converting algae to fuel is to start small. The University of Arkansas is working on a project converting algae — with low levels of lipids, but high levels of sugars — into butanol, an alcohol-based fuel (like ethanol), which could be used in automobiles.
The project came about after the university began working with companies who were using algae to clean up nitrogen and phosphorous from the Chesapeake Bay tributary system, says Jamie Hestekin, assistant professor of chemical engineering at the university, who is leading the effort.
Hestekin and his team of students have developed a more efficient means of fermenting the algae, and separating out the sugars that can be converted to butanol.
One group of honors students has created a small unit that can take dry algae and convert it to fuel-grade butanol, Hestekin says. The idea is that a farmer can grow algae on up to an acre of land, turn that algae into fuel (one acre of algae would make about 10 gallons of fuel), and then use the fuel to run farm equipment. The algae waste that’s not turned into fuel can be used as fertilizer, he says.
“What’s 10 gallons a week, really?" Hestekin asks. "There are two million farms of 100 acres or more. What if 10 percent made 10 gallons a week?”
The real impact of the technology, however, will come about if algae can be used to power automobiles. But how do you get from small-scale, single-units that power farm vehicles to passenger cars?
“If you can get the costs right, you could build a plant to do this,” Hestekin says, estimating it would take five to 10 years to achieve that. “We are Americans, we are concerned about the world we are leaving for our children. If we can get costs in the right ballpark, more people may be interested.”