John Abbott Sample Algae

Algae: America’s Next Super Fuel?

Sample/excerpt from John Abbott Communications [email protected] 707-765-9868

Pond scum used to have a bad rap. Not anymore. By John P. Abbott

I

n most cases, a sewage plant isn’t the kind of place you’d show off to potential investors, eminent scientists or grant makers with open checkbooks. But the Laguna Treatment Plant in southwest Santa Rosa is attracting the attention of eco-advocates around the country. It’s demonstrating algae’s potential to “polish” wastewater, turn pollutants into resourcerich methane, and—perhaps in the near future—produce biodiesel that could fuel our cars, buses and trucks. 1 NORTHBAY biz

February 2009

For the past 18 months, the City of Santa Rosa has teamed up with researchers from Sonoma State University to study the use of algae to purify wastewater and, at the same time, convert it into biofuel to help run the plant. The Aquatic Biomass to Fuel (ABF) project hopes to demonstrate that converting algae into biofuel is a cost-effective, easily replicated technology that can be used by municipal wastewater facilities throughout the United States. It could be years before the technology can be used on a commercial scale, but so far, the green, leafy globs of high-powered vegetation are doing exactly what their caretakers had hoped they’d do—and more. [Duncan Garrett Photography]

February 2009

NORTHBAY biz 2

“We’re getting good data, but this is really just the start,” says Professor Michael Cohen, a biologist at Sonoma State University who’s been studying aquatic vegetation for nearly 20 years. “We’ll be looking very closely at the lab results and scaling up from there.” With funds from the City of Santa Rosa Utilities Department, Cohen and graduate student Catherine Hare worked with R.S. Duckworth Construction of Sebastopol to build six narrow algae channels next to wastewater clarifying tanks. The “crop” of floating algae is designed to scrub wastewater, which flows through the channels in a serpentine pattern, by essentially “eating” nutrients and harmful components while at the same time producing biomass—carbohydrates, proteins, nucleic acids (including DNA) and lipids (some of which are, basically, vegetable oil). Ultimately, the biomass will be fed to digesters, which are processing machines that work anaerobically (without oxygen) to convert it into methane-rich biogas that will then be used to generate electricity to power the plant. Aided by grants from the Bay Area Air Quality Management District and the California Energy Commission, an experimental digestion facility is under construction at the city’s Laguna treatment plant. The beauty of anaerobic digestion, says Cohen, is that it converts all the biomass substances, not just a portion of the lipids, into a useable energy source (methane). “We’re learning about the operations of the channels and ways to improve the efficiency of removing the residual nutrients to make the water even cleaner,” Cohen explains. “We’re also investigating how useful the scrubbers could be in removing residual pharmaceuticals and personal care products from the water. Rather than just treating the biomass we pull out as garbage, we’re trying to convert it to methane and other products we can use for energy. For instance, we’ve seen that when we put

edge approaches to reducing greenhouse gases at the local level. The project was recognized yet again last October, when it received one of four innovation awards from the Interstate Renewable Energy Council (IREC). “This project combines the best of the best by helping us clean our wastewater in a biological way and produce fuel for our electric vehicle fleet at the plant,” says Dell Tredinnick, project development manager for the City of Santa Rosa. “We’re in a position to advance the science of this for communities across the country.” Although Cohen and Hare can make biodiesel from algae in laboratory beakers, it’s too early to tell if they can produce the same results on a much larger scale. But others are aggressively pursuing that goal, including several companies in the greater Bay Area (see “Bay Area Algae Companies” on page 36). The most optimistic say algae-based biodiesel could hit the streets within the next 18 to 24 months and be available from any retailer that currently sells diesel. But the fact is, almost all of these companies are still in the research and development or demonstration phase and won’t provide specifics about their proprietary processes, technology, production rates or energy costs. Justifying the hype A number of alternative energy sources have offered promises for a cleaner, greener and more energy-secure future, but algae’s potential seems to justify the hype. Because the algae make oil naturally, it can be refined into gasoline, diesel, jet fuel and chemical feedstock [raw material used to produce energy] for plastics and drugs. It can be processed at existing refineries and manufacturing facilities, thereby eliminating the need for investments in new infrastructure. And it can clean up waste by

“We’re in a position to advance the science of this for communities across the country.” —Dell Tredinnick, City of Santa Rosa together certain mixtures—such as dairy and winery waste—we get a synergistic reaction that produces more biogas than if we just added them up individually.” Cohen’s design isn’t revolutionary; the idea of applying algae to treat wastewater has been around for decades and, he’s quick to point out, the cumulative research on the subject is now helping to pull all the kite strings together at the same time. But Cohen’s use of floating mats of aquatic vegetation is a unique approach to the process—and one of the things that makes the Laguna project self-sufficient and, thus, more practical and economical than other alternative energy initiatives. The county’s collaboration with Sonoma State has propelled it into the national spotlight. In May 2008, the ABF project won the National Climate Innovation Invitational Award, which Professor Michael Cohen in the laboratory at Sonoma State University [Duncan Garrett Photography] showcases cutting3 NorthBay biz

processing nitrogen from wastewater and carbon dioxide from power plants—an especially attractive proposition given the growing interest in carbon tax credits. Algae—rootless, stemless, leafless plants found in pond scum, seaweed and water—use photosynthesis to transform carbon dioxide and sunlight into energy. In the process, some species can theoretically produce up to 30 times or more oil per acre than other plants used to make biofuels. They grow much faster than plants like soybeans and corn, in some cases doubling their weight many times in a single day, and can be harvested in coastal or desert areas, where groundwater conditions are less than ideal. They can eat just about anything, including wood chips, corn stalks, sugarcane, even agricultural and industrial waste. Wastewater from domestic and industrial sources contains rich organic compounds that actually accelerate algae’s growth, essentially turning a waste stream into a valuable resource. There are some obstacles to widespread production of algae for biofuels, however. One is finding the right type of algae, which has high lipid content—the percentage of its cells that yield oil—a fast growth rate and that isn’t too difficult to harvest. Scientists have found some types of microalgae can produce as much as 60 percent of their weight in oil—some can even double their mass several times in a single day—but only when they’re starved for nutrients. Unfortunately, when they’re starved for nutrients, their ability to grow and reproduce slows down. (These microalgae, Cohen stresses, are very distinct from the algae used in the ABF system.) Another challenge is developing a cost-effective, controlled Reprint from February 2009