Energy, Water, and Fuel are three of the world’s most pressing needs. Algal biofuel can have a major impact on all three observed Dr. Michael Webber in opening the recent American Association for Advancing Science (AAAS) workshop about the future of fuel from algae.
Algae seems to grow everywhere except in commercial fuel processing plants. Algae grow unwanted in our showers and swimming pools. There are over 30,000 species living on land and in water. Algae include seaweed and pond scum. Scientists are actively searching for the ideal forms of algae to convert our waste and CO2 into fuel. The idea is simple: grow algae, separate the fatty lipids from water, then refine the lipids into biofuel. Producing high volumes of algae biofuel at low cost, however, is anything but simple.
Algae multiply rapidly with up to 50 percent of their weight being lipids, or triacylglycerols, which can be extracted and converted into fuel. Yes, biodiesel and other transportation fuels can be made from algae, but after decades of effort the fuel is still expensive and only made in lab-scale quantities. There are many obstacles to replacing petroleum with algal fuel in this decade. As I took notes at this three hour workshop that includes top experts in algal fuel, I had hoped to deliver a more optimistic report, but no optimism was gushing in the room.
Even if 10 million of the 240 million vehicles in the U.S. are replaced with plug-ins in this decade, that leaves 230 million vehicles needing petroleum fuel, often sourced from countries that don’t like us, or from sources such as tar sands with massive carbon emissions. Biofuel could reduce our dependency on oil. Fuel from algae can include ethanol, biodiesel, bio-jet fuel, and even bio-crude which could be refined and blended at existing oil refineries.
Currently, biofuel from corn, soy, and palm competes with food, uses large inputs of water, ammonia, petroleum, and land. Demand for food goes up; rainforests that supply our oxygen get destroyed.
“If we were to replace all of the diesel that we use in the United States” with an algae derivative, says Solix CEO Douglas Henston, “we could do it on an area of land that’s about one-half of one percent of the current farm land that we use now.”
Scientists at the AAAS conference seem to agree that 4,350 to 5,700 gallons of fuel per acre of algae per year is realistic. This is 10 to 100 times the potential of other fuel sources ranging from soy to jatropha. Land use is not an issue. Algae thrives on CO2, creating the dream of co-locating algal production at power plants and cement plants.
The DOE states, “Despite their huge potential, the state of technology for producing algal biofuels is regarded by many in the field to be in its infancy. There is a general consensus that a considerable amount of research, development, and demonstration (RD&D) needs to be carried out to provide the fundamental understanding and scale-up technologies required before algal-based fuels can be produced sustainably and economically enough to be cost-competitive with petroleum-based fuels.” Now available is a 214-page draft PDF of the National Algal Biofuels Technology Roadmap.
Thousands of strains of algae are being tested by private companies, universities, and research institutions. To achieve higher sustained production of triglycerides, hundreds of variables are being tested including natural strains, GMO strains (many patented), water, light intensity, nutrients, and nitrogen starvation.
Oil must be “brewed” with the right solution, light, mixing, and stirring. Cost-effective photobioreactors must be developed. Dr. Bob Hebner, University of Texas at Austin, has produced 6,000 gallons of algae in one day. Low cost targets appear achievable – $2 per gallon to produce algal oil and another $2 per gallon to process. Yet these are only achievable if the right organisms can be kept alive, water input reduced, energy costs reduced, and lipids can be separated at much lower cost. Costs must be removed at each of these steps:
1. Growing the desired strain. Major problems include predators, competing strains, and death of the needed strain.
2. Harvesting – removing water at low cost
3. Lysing to produce a lipid concentrate
4. Separations – oil from water from biomass
To achieve low cost and volume production, different pathways are being explored including anaerobic digestion, supercritical fluids, pyrolysis, and gasification.
Although algal fuel does not compete with food, it currently does compete with water. For large scale processing use of water will need to be drastically reduced to be economical with the energy cost of pumping water. Waste water or salt water will be needed, not water needed for agriculture. Optimization can likely drastically reduce needed water which can then be recycled.
Genetically modified organisms are controversial. To date, no consistent output from natural algal systems has been achieved. At the AAAS conference, Dr. Dan Kammen, U.C. Berkeley and IPCC lead author, discussed how natural strains of algae could be possible in global small scale production. He expressed concern that although GMO can cause highly productive algae, their inevitable release into other biosystems could be highly destructive.
With its ability to sequester CO2, algal fuel production will benefit from cap-and-trade legislation that exists in many states. Algal fuel can be produced in all 50 U.S. states.
Although the challenges are many, the potential of algal fuel is enormous. Exxon is investing $300 million in Craig Ventor’s Synthetic Genomics with plans to produce fuel from algae. Mexico’s BioFields is investing $850 million in an Algenol Biofuels plant for ethanol from microalgae; Dow is adding $50 million to the venture.
Greg Horowitt, T2 Venture Capital, reports that hundreds of millions are being invested in algal fuel companies such as Sapphire Energy, Aurora BioFuels, BARD, Solix, GreenFuel, and Solazyme. From Boeing to BP, from DARPA to DOE, and from Arch Venture Partners to Bill Gates, serious money is betting that algae will someday be a major biofuel source for our trucks, ships, and planes.