Biofuel Future | Flying Magazine

Biofuel Future

Aviation’s mandate is to replace half the global jet fuel supply — 45 billion gallons a year — with sustainable biofuels by 2040. How will we ever pull it off?

Aviation Biofuel

Aviation Biofuel

It wasn't many years ago that the idea of using biofuels for flight was dismissed out of hand as a utopian fantasy. The conventional wisdom said we’d never be able to produce enough aviation biofuel to make a difference, and even if we could it wouldn’t matter — biomass-sourced fuel would wreak havoc on the delicate internal workings of turbofan and piston engines with steep penalties in power and efficiency.

Fast-forward to 2012, and we’re on the verge of an enormous leap ahead as the industry ramps up aviation biofuel production to levels that will indeed have a palpable impact.

How did we come so far so fast, and where are we headed next?

While it’s true that our planet has plenty of oil remaining — vast reserves, in fact, locked deep below the surface to satisfy many decades of demand — the flip side of this narrative is that we’re using the oil we’re producing faster than at any time in our past. Increasingly, oil prices are being driven by the world’s insatiable energy demands, especially in emerging markets in Asia and South America, where consumers are growing accustomed to improved standards of living and craving ever more energy. Indeed, almost two-thirds of the growth in world oil demand in recent years has come from China and other growth economies.

If you’ve ever wondered what a prolonged oil price spike would mean for aviation, you’re not alone. Some of the brightest minds at Boeing and Airbus and inside the boardrooms at the world’s biggest airlines and the Pentagon have been asking that very question. The troubling answer everybody keeps circling back to doesn’t paint a reassuring picture of the future. Over the long term, say many energy experts, the price of a barrel of oil is headed in only one direction: way up. In the shorter term, price instability will stoke fear and uncertainty every time the price of a barrel of crude hits a dizzying new high. You probably don’t need to be told, but it’s the number one worry on the mind of most every airline CFO around the world.

What’s clear is that the days of tapping into reserves of free-flowing “easy” oil are growing shorter. Increasingly, we’re having to drill deeper and get more creative to extract the oil we know is there — much of it stubbornly locked in shale or oil sands. At the same time, world governments concerned about environmental catastrophe from the release of man-made greenhouse gases into the atmosphere are intervening with hefty taxes that will only drive fuel prices higher. Connect the dots, and it’s obvious we’re on a path to ever-higher prices that, if continued unchecked, will eventually lead to the day when we can no longer afford to fill our tanks.

For owners of light, single-engine airplanes, relief could come in the form of battery power and electric motors, which would allow future generations of weekend fliers and flight students the joy of an hour or two of time aloft before the batteries drain and it’s time for a recharge. Without some kind of electric breakthrough, for everybody else, from owners of high-performance singles up through the turbine world, there really aren’t any realistic alternatives to liquid fuel. We’ll never see the day when an Airbus A380 is powered by lithium-ion batteries and sunlight, for example. In short, turbine-powered airplanes need kerosene or its liquid-hydrocarbon equivalent to keep flying.

Faced with the reality that aviation’s demand for energy sourced from liquid fuel cannot be reversed — and that governments will insist airlines abide by a carbon-neutral growth strategy or pay the price — a massive effort is now under way to encourage the formation of an entirely new industry based around production of huge volumes of aviation biofuels made from everything from micro algae and hearty plants and grasses to discarded animal fats and even the garbage you leave by the curb. The aviation industry is laying huge bets that fuel produced from biomass can one day replace 50 percent or more of the world’s jet fuel supply. When you stop to consider that the industry currently burns 70 billion gallons of jet-A each year — a figure that is projected to rise sharply in the decades ahead, by the way — the enormity of the task, and the consequences of failure, begin to sink in.

Fuel vs. Food
Global biofuel production has tripled in the last decade, but it still accounts for less than 3 percent of the world’s transportation fuel supply. Yet the challenge doesn’t lie in our ability to ramp up biofuel production. Rather, the major difficulty will involve creating a sustainable model for the future that doesn’t impact the global food supply. Experts say so-called second-generation biofuels, which use nonfood crop sources and low-water irrigation, are the answer. These feedstocks can be grown on nonfarm land and in arid conditions — even in deserts, some researchers say.

When we think about “biofuels,” the vision that is likely to pop into our heads is of vast green fields being combed over by industrial combines that initiate the cycle of sending freshly plucked greenery off to fuel production facilities for processing. That’s not how it will happen, say the scientists who insist the biomass we collect for aviation fuel must not compete with food supplies. Will it really be possible to furnish the world with billions of gallons of aviation biofuel without driving up food prices in the process? Surprisingly, researchers say yes. In fact, they insist, it’s the only way the aviation biofuel model can exist and flourish over the long term.

“We don’t yet fully understand how much total land will be needed to meet aviation’s future fuel needs, but we’re incredibly positive about the science being pioneered by those at the vanguard of this effort,” said Darren McFadden, director of sustainable fuel strategies at Boeing. “The research is showing us, for example, that we can grow biomass on arid desert lands using seawater for irrigation. That’s really exciting.”

The aviation biofuel industry, for practical argument, is only about six months old. Last July, for the first time ever, the aviation industry approved biofuels for everyday use in turbine airplanes, testing and certifying a 50:50 blend of conventional jet fuel mixed with feedstock-derived biofuel.

In August, President Barack Obama announced a $510 million incentive plan to speed aviation biofuel production by building new refineries or converting existing ones. Early flight trials have shown great promise for this new “drop-in” fuel source, as several airlines have begun using the approved blended biofuels on commercial flights with results that demonstrate no reduction in engine power or efficiency compared with using conventional jet fuel. Safety is unaffected as well.

Produced from plants with lyrical-sounding names like jatropha and camelina, as well as other feedstocks including algae and salt-tolerant halophytes, these drop-in fuels hold the promise of ensuring aviation’s long-term viability and, many believe, are a steppingstone to new generations of biofuels that eventually could completely replace petroleum-based jet-A, and possibly even 100LL aviation gasoline.

While most biofuel research has been focused on developing alternatives to jet-A, there has also been a push to create biofuel-based avgas. Swift Enterprises, which operates out of Purdue University’s research park in Lafayette, Indiana, has developed the 100SF synthetic hydrocarbon fuel alternative to 100LL (aviation-specific low-lead gasoline). The 100SF fuel is produced from biomass, which is then chemically reacted to produce full hydrocarbons. According to Swift Enterprises, commercial production of the 100SF fuel could begin soon. Test flights of the fuel have taken place in a Beechcraft Bonanza G36 as well as a Van’s Aircraft RV-3 and RV-4.

Ethanol’s Missteps
Assuming we can indeed produce billions of gallons of this vital combustible nectar without wiping out entire rainforests or invading the farmland we’ll desperately need for future food production, half the battle will be won. The other half of the challenge, as you might have guessed, involves brining down the price of biofuel until it falls in line with what we pay at the pump for conventional jet fuel. That will be a daunting challenge indeed. We need look no further than the ethanol industry for a cautionary tale of how we might fail in this regard.

Ethanol was supposed to help us kick our oil habit while putting more money in farmers’ pockets and ushering in a new era of guilt-free motoring. Instead, the price of corn has gone up while government subsidies have lined the pockets of agribusiness giants. For more than 30 years, the federal government has offered tax credits and imposed a tariff to stimulate U.S. production of ethanol, nearly all of it from corn. The goal: to reduce the nation’s reliance on foreign oil. Now, Congress is pushing to eliminate billions of dollars in subsidies for the ethanol industry, sending a strong message that the era of big taxpayer support is ending. Few outside the corn-growing industry are lamenting the subsidies’ potential demise.

“Probably the best thing for the aviation biofuel industry was the backlash against ethanol,” McFadden said. “It made the aviation industry take a step away from the subsidies model that hasn’t worked and focus on technology instead.”

Boeing, Airbus and 25 airlines have signed a sustainability pledge through the Sustainable Aviation Fuel User Group ( that promises the aviation industry will develop biofuels that perform equal to or better than petroleum-based fuels, with a carbon-neutral life cycle from production through end use.

So how much does a gallon of aviation biofuel cost? That’s a hard question to answer, but we know it’s currently far more than jet-A’s cost. The Navy recently signed deals to buy 450,000 gallons of biofuel as part of an aim of obtaining half of its fuel from alternative sources by 2020. But at approximately $15 per gallon — nearly four times the price of traditional jet fuel — the new fuels aren’t cheap. The Navy’s $12 million fuel purchase will be used in the Pacific near Hawaii this summer, where F/A-18s powered by fuels fermented from algae will launch from the deck of an aircraft carrier. A destroyer and cruiser, meanwhile, will join the carrier on a voyage across the Pacific using fuel made from waste fats and greases. (The carrier itself runs on nuclear power.) It will be the first demonstration of the so-called “Great Green Fleet” — an entire aircraft-carrier strike group running on alternative energy sources.

Two companies are splitting the Navy’s biofuel order. Dynamic Fuels, half-owned by agribusiness giant Tyson Foods, converts fats and waste greases into biofuels. The other firm, Solazyme, uses algae as a means of fermenting everything from plant matter to municipal waste into fuel. Both are considered leaders in the next-generation biofuel industry. Dynamic Fuels is one of the first companies in the field to bring a commercial-scale refinery online, while Solazyme has already delivered 150,000 gallons of its fuels to the Navy. This new purchase, at first, will cost $26 per gallon, or $1,092 per barrel. The biofuel will then be blended with an equal amount of conventional fuel, producing 900,000 gallons — for a real price of about $15 per gallon for the 50:50 blend. The Navy currently pays less than $4 a gallon for its JP-5 jet fuel, so the price difference is significant. Still, it’s roughly half of what was paid in 2009 by the Navy for an earlier biofuel trial.

Biofuel Breakthroughs
Researchers estimate that 85 percent of biofuel production costs are related to the raw materials — namely, biomass that isn’t yet being produced in high enough quantities. But that’s about to change. In the next two to three years, large biofuel production plants will be built as producers lease the land they will need to grow biomass. Eventually, the hope is that, as production of conventional jet fuel grows more costly and biofuel production increases, the cost lines will intersect and a gallon of biofuel could actually cost less than a corresponding gallon of jet-A.

“Biofuel costs will come down as production increases and these new fuels become a global commodity,” said Jim Rekoske, vice president for renewable energy at Honeywell UOP, which licenses green fuel technologies.

That’s predicted to happen fairly soon as biofuel science makes rapid strides. Rekoske’s team, for example, has been at the forefront of creating new types of renewable jet fuel from a type of alcohol called isobutanol, which can be produced from inedible biomass sources, such as corn stover, bagasse and wood residues. The FAA recently awarded a total of $7.7 million in contracts to eight companies — Honeywell UOP, LanzaTech, Virent Energy Systems, Velocys, Honeywell Aerospace, Metron Aviation, Futurepast Inc. and Life Cycle Associates — to help advance alternative commercial jet fuels, part of the Obama administration’s biofuels push.

Virgin Atlantic flew the very first biofuel test flight in 2008 between London and Amsterdam, using a 20 percent blend of biofuels in one engine of a 747 — a tentative first step, to be sure. Since then, several other airlines, including JAL, KLM, Lufthansa, Finnair and Continental, have flown scores of biofuel test flights, paving the way for the commercial approval of the 50:50 aviation biofuel blend by the ASTM last summer. Why 50:50? Researchers say this ratio is considered a conservative level while engineers study the effects of running biofuel through turbofan engines. So far, biofuel appears to behave much like petroleum-based jet fuel, with no additional wear on parts or gumming up of seals. That’s encouraging for proponents of even higher-ratio biofuel blends.

Virgin founder Sir Richard Branson was an early backer of biofuel research because of his concerns about global warming. For years, aviation interests have noted that the industry’s total contribution to man-made greenhouse gases is a scant 2 percent. However, the predicted rise in global air traffic in the next 25 or so years will lead to a 50 percent increase in that figure — to 3 percent, or around 20 million cubic tons a year. Compared with what our cars and trucks spew, that isn’t a lot — but some scientists believe that carbon dioxide emitted at the flight levels is more harmful to the environment than what’s being created at ground level. This is one reason aviation emissions are included in the highly controversial European Emissions Trading Scheme (ETS), a cap-and-trade program whereby operators of aircraft weighing more than 12,500 pounds will have to buy permits to offset their greenhouse emissions within Europe.

Development of more fuel-efficient jet engines will help appease regulators by keeping the industry’s carbon footprint in check, but without biofuels
the industry will almost certainly face steep ETS-related penalties in the years ahead while also being held hostage to oil price spikes. Whether it’s a concern about oil scarcity and skyrocketing prices or the threat of man-made global warming, the answer to our future energy needs appears to be the birth of an industry to support sustainable biofuels produced in mass quantities with stable costs. By no means will this transformation be easy, but with the full backing of industry, governments and the public — and with a little bit of good fortune — the future for aviation biofuels appears incredibly bright.

View our aviation biofuel photo gallery.


More Stories