Making jet fuel in your fields; runway not included

By Dick Hagen
The Land Staff Writer

November 23, 2007 11:15 am

— A relatively unknown American crop called cuphea might eventually work its way into your crop rotation — as a new jet fuel source.
Cuphea’s purplish flowers produce seeds with 30 to 35 percent oil (soybeans are 20 percent) and hydrocarbon molecules 8 to 14 carbons long, virtually the same carbon chain used in JP8, the moniker for today’s military jet fuels.
Ted Aulich, senior research manager at the Energy & Environmental Research Center in Grand Forks, is a process chemist working on alternative fuels for the aviation world. Speaking earlier this year at a field day at the U.S. Department of Agriculture-Agricultural Research Service’s 130-acre Swan Lake Research Farm at Morris, Aulich said U.S. military forces are using upwards of 10 billion gallons of liquid fuel annually. Nationwide, America’s annual consumption is about 135 billion gallons gasoline and 50 billion gallons diesel fuel.
“The push is on to come up with fuel sources other than crude oil,” Aulich said. “At our Research Center, we have a staff of 300 people, a $27-million-per-year budget, and a research mission to find answers to our energy issues.
“Currently about 60 percent of our research efforts are coal oriented. We have 600-plus years of coal reserves here in America. But we’re also plugging into renewables such as this interesting crop called cuphea,” he said.
Driving the mission of the Grand Forks research center is the military’s ambition of a “single battlefield fuel concept” rather than the logistical challenge of providing gasoline, diesel fuel and jet fuels.
Technology is already in place for converting coal to fuel, but it is three times more energy-intensive than converting crop oils into fuels, especially from sources such as cuphea. Aulich said they are just a few months into an 18-month project, potentially involving cuphea. Performance chemistry of these new fuels is challenging. Jet fuel, for example, withstands temps of 120 F to minus 50 F. “But because cuphea has about the same carbon chain as jet fuel, it certainly has promise.”
Now for the agronomic realities.
ARS scientist Russ Gesch has been studying cuphea for seven years at the Swan Lake station. He said about 260 different species, or lines, of cuphea have been identified to date, even though the crop was domesticated only 25 years ago. Gesch, a research plant physiologist, shared some basic facts about cuphea:
• Cuphea seeds are small, only about 3 millimeters.
• It has an indeterminate growth so flowering extends over a long time period.
• Seed shattering occurs as the plant matures.
• The seed cluster tends to be somewhat sticky.
• It requires timely management to get 1,000-pound yields.
• Because of its shallow roots, it is susceptible to drought, and is also heat sensitive.
Gesch estimated only about 700 acres of cuphea were grown in 2006. Technology Crops International of Winston-Salem, N.C., currently licenses growers, mostly in Minnesota and North Dakota. Used primarily in the cosmetic industry, cuphea is a high-dollar market.
He said that because of its special carbon chain molecules, it might work as a fuel similar to No. 2 diesel without modification. It could also be used as a special lubricant. “It stays liquid down to minus 43.6 F so it also has potential as an engine lubricant,” said Gesch.
Plot work at Swan Lake indicates cuphea production costs are comparable with soybeans. Swathing helps overcome the indeterminate flowering challenge. Use of a desiccant lessens combining problems.
Though it appears cuphea is at best a “dark horse” candidate as a new renewable fuel resource, some common weeds could get on the research agenda, such as pennycress and camelina. Gesch said that in Illinois trials, fall-seeded pennycress, then soybeans seeded shortly after harvesting the pennycress in late spring, have produced 2,000-pounds-per-acre pennycress, plus the soybean crop.
A male sterile line of cuphea might result in new hybrids in the future. Gesch said selective breeding and more research can improve cuphea, much as soybeans have dramatically improved over the past several years. Archer Daniels Midland has done pilot work on cuphea oil extraction. General Electric and Honeywell also are doing research on alternative crops for future fuels.
“This is still a very young industry,” said Aulich. “What we are learning today may be dwarfed by new science, new technologies just around the corner. Will cuphea be part of that future? Stay tuned.”

Copyright © 1999-2008 cnhi, inc.