In the U.S., the U.S. Department of Agriculture’s Forest Products Research Laboratories and several leading universities are advancing hardwood to bioethanol conversion, emphasizing willow and other low-density hardwoods, including poplar, aspen, and cottonwood. In these woods, the lignin is less cross-linked and there is a higher hemi-cellulose content, which make it easier for enzymes to degrade it. (Softwood, in contrast, has highly cross-linked lignin, long fibers, and recalcitrant cellulose crystals, all of which make it hard to degrade.)
Algae may offer an alternative to cellulosic biomass or grain. “Algae is easy to break down and less energy is spent growing it” than other crops, analyst Alexander says. It also provides a ready use for the CO2 generated by coal-fired power plants, helping them become carbon neutral.
The National Renewable Energy Laboratory indicated that, theoretically, growing the equivalent of 15,000 gallons of oil per acre per year was possible in open ponds. That’s about 30 times more oil than land-based plants, according to the U.S. Department of Energy’s Aquatic Species Program: Biodiesel from Algae.
Global Green Solutions (www.globalgreensolutionsinc.com) believes it can produce 180,000 gallons of oil per acre per year by using vertical bioreactors in greenhouses to increase the density per acre and to better control such issues as contamination, evaporation, heating, and cooling. Craig Harting, COO, suggests the costs of the algae oil, scaled to hundreds of thousands of gallons, would be 30% less than the cost of other crop-based feedstocks.
Global Green Solutions is in the R&D phase, installing a small, quarter-acre pilot plant. The operating plan is to produce and harvest algae, extract oil from that, and sell the oil to biodiesel refineries. Biorefineries would like a guarantee of 10 million gallons per year—a 50- to 55-acre facility.
“The process is continuous and completely self-contained,” according to Harting. Water and air are filtered, and the algae replicates four to six times per day. Thanks to the tight controls, Global Green Solutions can select and cultivate individual cells based upon their attributes. “We’re trying to optimize our oil around carbon 13 or carbon 14 chains,” Harting says, noting that there are thousands of strains of algae and many different product opportunities. The native strains Global Green Solutions uses yield about 50% of their weight in oil, with the remainder having value as fertilizer.
The open pond method is favored by LiveFuels (www.lifefuels.com). Plans include growing the algae, which thrives at 23°C, in ponds, first in southern California and later in north central California, according to Lissa Morganthaler-Jones, CEO.
LiveFuels plans to genetically modify native algae to increase lipids and other valuable attributes, working with Sandia National Laboratory, the National Renewable Energy Laboratory, and academic institutions. Current, early work focuses on Botryococcus braunii, which, she says, has 20- to 40-carbon long chains. Other researchers indicate hydrocarbons constitute between about 30–75% of its dry mass. The goal, Morganthaler-Jones says, is “to provide intermediate feedstock.”
Blue Sun (www.gobluesun.com) is taking a different tack, working to hybridize oil seeds to produce more oil. The company is working with winter and spring canola and, for dry land, canelina. “We’ve had about two years of field trials,” researcher Charlie Rife, Ph.D., says, and are seeing increases. CEO and president Jeff Probst expects it to take more than 10 years to develop a few commercial feeder seeds. Once the seeds are optimized, they’ll be planted and much of their seeds will be crushed by Blue Sun for B-100 and B-20 biodiesels. “The cost is about the same as for diesel fuel,” Probst says.