The Future of Flying
At the edge of town in Klamath Falls, above a landscape of fertile fields and
wetlands, the roar of military jets punctuates the sky.
Jet fuel keeps those planes aloft. And rubber tires land them safely on the ground.
Both jet fuel and natural rubber have significant strategic value to national defense, and
that’s why the U.S. government is eager to find a domestic source for these materials.
Part of that search is happening right across the street from the Air National Guard’s
runway, at the Klamath Basin Research and Extension Center.
F-15s fly over fields growing plants for making jet fuel and aviation tires. From ground level, some of the experimental plots might look like a crop of weeds. In fact, they are weeds, of a sort. They are Russian dandelions, and although they look nearly identical to the common yellow blossoms that frustrate gardeners, these dandelions contain an abundance of stretchy latex that could become a homegrown source of natural rubber.
Although cars can run on tires made of a blend of synthetic rubber, aircraft require natural plant-based latex rubber with the right molecular structure to stand up to the extremes of aviation. And currently, the major sources of natural rubber grow only in the tropics, mostly in southeast Asia.
In Klamath Falls, Oregon State University agronomist Rich Roseberg is leading the study of Russian dandelion. But Roseberg’s not the first one to notice the potential value of such a humble plant. Josef Stalin understood the importance of securing a domestic supply of rubber, and during the 1930s he ordered his Soviet scientists to examine the potential of their domestic dandelion, whose carrot-like roots hold up to 10 percent of their dry weight in latex.
“When Josef Stalin tells you to do something, you do it,” Roseberg laughed. And soon American researchers took notice of the plant, too, when the war with Japan cut off western access to Asian supplies of rubber. “During World War II, Russian dandelion was grown in several parts of the U.S., including the Klamath Basin, where it was reported to have fared well,” Roseberg said. But interest in the yellow flower soon faded when the war ended and the world regained access to Asia’s rubber. Equally important was that petroleum for synthetic rubber was suddenly cheap and plentiful.
Fast forward to 2012. Demand for natural rubber again outstrips supply, as prices for both rubber and petroleum are reaching record highs. The worldwide value of natural rubber is now estimated at $3.8 billion, and the search resumes for an alternative to the tropical rubber tree.
Roseberg’s work builds on studies begun years ago by OSU researcher Daryl Ehrensing, who passed away in 2009. Funded in part by Sun Grant, Roseberg is currently collaborating with researchers from Ohio State University who have been studying the manufacturing qualities of latex from Russian dandelions, which performs like latex from the tropical rubber tree, but without the proteins that cause latex allergies.
“Here at Klamath Falls, we’re figuring out the germination and growing requirements of these plants,” Roseberg said. “Being a hardy annual, you’d think you could just throw out the seeds and they’d grow. It’s actually more challenging than we thought to direct-seed Russian dandelion and get a good crop.”
Once established, Russian dandelion requires relatively little water and fertilizer, and it can be grown on marginal land or in rotation with other crops. The plant grows well in cooler parts of the country, so Eastern Oregon—where root crops such as potatoes and sugar beets thrive—could be a suitable place to grow the rubber-rich roots. Equally important, Oregon’s well established seed industry could cultivate seed here to use for planting in other parts of the country, Roseberg said.
The National Guard jets continue their touch-and-go maneuvers across the street from Roseberg’s research plots. Those aircraft not only require a higher quality of rubber in their tires, they require a higher quality of fuel in their tanks. And although cars can run on electric batteries, aircraft require fuel.
“Aviation uses an incredible amount of fuel,” said John Talbott, director of the Western Region Sun Grant, based at Oregon State. “The industry’s biggest uncertainty is not ridership, but fuel prices.” Of all the factors impacting fuel prices, many are unpredictable, such as Middle East politics or hurricanes in the Gulf. One way to stabilize long-term prices would be to find alternative fuel sources that can be produced renewably and domestically.
The U.S. military is particularly interested in finding an alternative, renewable source of fuel for its tactical and weapons systems, according to a 2011 study by the U.S. Department of Defense, entitled “Opportunities for DoD Use of Alternative and Renewable Fuels” (FY10 NDAA Sec 334 Congressional Study). The report estimates that current combat missions in Afghanistan require 22 gallons of fuel per service member per day. And because fuel makes up 80 percent of military supplies carried by convoys in the region, an overreliance on petroleum puts American soldiers at risk and military budgets in the grip of global oil markets.
“Currently, fuel for the Afghan war has to go through Pakistan at a cost of about $400 a gallon. Imagine if we were growing camelina in Afghanistan,” Talbott said. “We could have fuel made on the spot.”
Camelina was highlighted in the Defense Department report as a particularly promising source for producing jet fuel. Although it, too, was widely grown in Russia and parts of Europe until the 1940s, camelina was largely displaced by higher-value food crops after World War II. Because its oil is relatively high in omega-3 fatty acids and low in saturated fatty acids, camelina is considered a high-quality edible oil as well as a source for jet fuel. OSU agronomists at KBREC and elsewhere have put camelina to the test and found that it can be grown with few input costs and under marginal conditions, so it has potential both as a dryland crop in Eastern Oregon and as a rotation crop with grass seed in the Willamette Valley
Camelina is on the radar screen of the Sustainable Aviation Fuels Northwest (SAFN), the nation’s first stakeholder partnership to explore the possibilities of growing a regional supply of aviation fuels. “Oregon State has been involved with SAFN from its inception and work continues to develop a sustainable and economically competitive source of renewable aviation fuels,” Talbott said. “We’re looking at oilseed crops like camelina and lignocellulosic sources such as hybrid poplar and wheat straw as potential feedstock for jet fuel.”
Another promising source of biofuels identified by both the Department of Defense and SAFN is among the most humble of plants: algae. “Microalgae are among the most efficient plants in converting solar energy to chemical energy,” said Ganti Murthy, a biological engineer at OSU who studies the energy potential of microalgae. “Some strains of microalgae contain as much as 50 percent oil in dry biomass, compared to 20 percent in soybeans, and they require far less land and water than terrestrial crops.”
Although the Defense Department report acknowledges that the availability of biofuels to meet the scale of military needs is still many years away, the U.S. Air Force, the Pentagon’s largest consumer of jet fuel, plans to acquire 50 percent of its fuel from biosources by 2016. Clearly, the search for bio-based flight has taken off.