Of course, making algae oil in quantity remains a huge challenge, from perfecting the algae’s growth to extracting the oil cost-effectively. According to Zenk, the company hopes to produce 300 barrels of oil from algae grown in brackish ponds at its test facility in New Mexico by 2011. In five years the output should reach 10,000 barrels a day, costing “between 60 and 80 dollars per barrel,” he says. “That’s with very conservative numbers in terms of oil produced per acre.” Other players are also at work in this area: Science Applications International Corporation in San Diego has a contract with the U.S. Department of Defense to develop fuels from algae, and the San Francisco–based start-up Solazyme has made jet fuel from algae that meets commercial standards.
Where to Grow
In the meantime, efforts to grow jatropha—already planted in quantity in Africa and India—may be scaled up while camelina is improved as a rotation crop with wheat. Jet fuel from camelina and jatropha should be at the correct price point—$80 per barrel or less—within three to five years and fuel from algae in eight to 10 years, according to Holmgren. Boeing’s Glover adds that “different parts of the world will source differently.” To that end, chemical engineers at the University of North Dakota’s Energy & Environmental Research Center have successfully turned oil from canola, coconuts and soybeans into jet fuel that rivals the conventional liquid, U.S. government tests show.
Sourcing would indeed be a big question. Critics question whether enough land would be available to meet demand. An article in the industry journal Petroleum Review claimed that supplying 240 million gallons of jatropha fuel—roughly the equivalent to the demand for Jet A—would require planting an area twice the size of France. Others warn that jatropha yields are unreliable and that harvesting seeds from the inedible fruit is labor-intensive. Genetic advances in biofuel plants could make them more productive [see “The Next Generation of Biofuels]. Nevertheless, if petroleum oil stays below $80 a barrel, none of the alternative fuels may pay.
Even if hurdles are overcome, bio-jet fuel in the near term is likely to be blended with Jet A because the biofuels lack aromatics—hydrocarbon rings that interact with the seals in current engines, helping to swell them shut. “We fully expect that the first fuels will be 50–50 blends or less,” Glover says. The recent flights—as well as earlier ones by Air New Zealand and Virgin Atlantic—prove that such blends can be effective. By 2017 the International Air Transport Association, an industry group that represents 93 percent of the world’s carriers, hopes to source 10 percent of all aviation fuel from sustainable plant sources, both to ease the volatility of fuel prices and to cut emissions of greenhouse gases. Boeing is optimistic, too. “Three years ago we started out saying this doesn’t look like it’s possible,” Glover says. “But every day we become more and more convinced it’s not only possible, it has huge benefits for industry and the public.”
Note: This article was originally printed with the title, "Green Fuels for Jets".