Al Bryant, a veteran Boeing engineer, moved to Beijing shortly after the Olympics to oversee the company’s R&D effort in China. He became famous in aviation circles for his role as a traveling proselytizer for the importance of biofuels in general and algae in particular. His presentation centers around a graph that projects likely emissions from airline travel through the year 2050. This chart has been the premise for Boeing’s argument that it is time for an all-out push for practical biofuels, especially from algae. The chart’s green wedge, showing the hoped-for carbon improvements from biofuels, would not simply keep the aviation industry from grossly increasing CO2 emissions as traffic goes up but actually reduce them to less than their 2009 level.
When an engine burns fuel from algae, it emits CO2 just as if it were burning fuel pumped straight from the Persian Gulf. But the algae would have removed at least as much CO2 from the atmosphere while it was growing. So in principle, and with allowances for inefficiencies and fuel costs in the production process, algae-based fuel could allow airplanes to fly on something much closer to a “carbon-neutral” basis, also sometimes called operating on a “current carbon cycle” (versus the “fossil carbon cycle” of burning coal or oil).
The aerospace argument for new biofuels takes full account of America’s ethanol disaster in the 2000s. In one of the worst policy mistakes of modern times, the U.S. government subsidized farmers to grow crops, mainly corn, that could be converted into ethanol and blended into gasoline supplies. This made no sense in energy-efficiency terms. (It took more energy to plant, fertilize, harvest, and process the corn than the ethanol yielded.) It made no sense in economic terms, except as a subsidy to the farmers and agribusiness. It made no sense in moral terms, since it diverted crops that could be used for human or animal feed into transportation fuel. So the aerospace standard is to find biofuels that don’t directly or indirectly compete with the human food supply; that represent true carbon savings as corn-based ethanol never could; and that can be sustainably grown and harvested without depleting water supplies or doing other long-term damage.
Whatever biofuel the aviation industry creates must have the same “energy content” as current fuels, so that aircraft as big and heavy as today’s can fly at comparable speeds. It must be compatible with the design and technology of current jet engines. It must be compatible with the existing worldwide infrastructure of fuel storage and distribution. And—trickiest of all—it must be interchangeable with today’s jet fuel, which is stockpiled at airports around the world. “You need to be able to leave Beijing with a tank full of biofuel, go to Lima, Peru, refuel there with normal fuel, and fly back,” Bryant told me in Beijing. “You can’t have an airplane stuck in Lima because it can’t use regular fuel.”
By process of elimination, these criteria have led mainly to algae. In principle it can produce five to 10 times as much fuel, per acre of surface area, as oil palms (which are largely grown on land where tropical forests have been clear-cut), soybeans, corn or other crops that can be used for biofuels. It grows and produces the oil many times as fast as more-complex plants—an algae crop cycle is a matter of days rather than weeks or months. It can be grown on land that is otherwise too barren or unusable, and in water that is too polluted or brackish for any other human or agricultural purpose. “The world’s entire aviation-fuel needs could be taken care of by algae facilities the size of Belgium,” Bryant said. (He waited for me to make the requisite joke about the highest and best use of Belgium’s landmass, which I did.) Other American and Chinese scientists I interviewed were skeptical that algae farming could become practical that quickly, or affordably, or at the needed scale. Nonetheless, Boeing’s calculations assume that a sustained world oil price of $90 per barrel or above would make algae-based fuel economically practical, once production techniques are improved. World oil prices peaked at above $140 per barrel just before the world financial collapse of late 2008. During the crash they fell to as low as the mid-$30s, then climbed above $80 by early 2010 and remained there through 2011.
Boeing is now working with a variety of state-owned research facilities across China on sustainable-fuel projects, especially involving algae. Chinese universities and technical institutes are among the world’s leaders in algae research, especially the descriptively named Chinese Academy of Sciences Qingdao Institute of Bioenergy and Bioprocess Technology. Here is where the world’s hopes for making aviation more environmentally sustainable may lie. Much of the worst—and best—news about the world’s environment is coming out of China. It’s worth noticing the good.single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.