Air travel is rapidly returning to pre-pandemic norms. Nearly 3.4 billion people are expected to fly this year, almost double the number in 2020. Those who thought COVID-19 might lead to a drastic and permanent decline in air travel were simply underestimating its importance in modern life.
Yet a rebound in air travel also brings challenges – and not just because Russia’s invasion of Ukraine has sent jet-fuel prices soaring. In 2020, the drop in air traffic cut carbon emissions by several hundred million tons. With air travel taking off again, so, too, will emissions.
Fortunately, greener air travel is on the horizon. Biofuels will play an increasing role in powering it. And in addition to their environmental benefits, these new sources of fuel will make the world less reliant on countries like Russia to meet energy needs.
New technology has already made flight more fuel-efficient. Since 1990, fuel burn per passenger-kilometer has dropped by more than 50% due to such innovations as high-performing wing technologies and AI-optimized flight paths. But those hard-won gains still weren’t enough to keep up with growing demand for air travel. So scientists sought to transform jet fuel itself – from fossil-derived kerosene to renewable, plant-based energy.
Early biofuels were produced from crops, such as corn and soybeans. The newest biofuels don’t compete with food sources, instead producing energy from inedible plants like switch grass or algae. Others divert food waste, like cooking oil, from landfills to convert to jet fuel. And unlike fossil fuels, which release into the atmosphere carbon that has been stored underground for millions of years, plants used for biofuels absorb carbon from the air as they grow, offsetting the carbon emitted when a biofuel burns.
The most advanced biofuels – known as sustainable aviation fuels (SAFs) – generate up to 80% fewer carbon emissions than kerosene. They can even reduce engine soot and contrails, which heighten the effect of global warming. SAFs can be used in any aircraft that currently burns jet fuel, without modification to the engine or plane.
In December, United Airlines carried 100 passengers on a flight across the United States in a plane powered solely by a sustainable fuel produced by Virent, made from vegetable oil and sugar water. This first-in-aviation moment further demonstrated the potential of biofuels to revolutionize air travel. But limited supply has hindered adoption, such that SAFs currently account for only 0.01% of global jet fuel use.
That’s poised to change. In September, the Biden administration set an ambitious goal of replacing all jet fuel with sustainable alternatives by 2050. In response, biotech companies are partnering with airlines and others to scale up production of biofuels.
Last fall, Delta Air Lines signed a deal with renewables company Aemetis to supply 250 million gallons of SAF over the next decade. Startup LanzaJet, with an investment from Microsoft, has started construction on a new biorefinery in Georgia to produce 10 million gallons of SAF per year. Chevron has teamed up with biofuel company Gevo to build two Midwest plants, where Gevo will convert 900 million gallons of ethanol to SAF.
Leaders here in Washington have spearheaded their own efforts to promote sustainable aviation fuels.
The Port of Seattle that manages Seattle-Tacoma International Airport was the first airport operation in the nation to lay out a specific timeline for a transition to sustainable fuels, with a goal of all flights to include a blend of at least 10% sustainable fuels by 2028.
US Sens. Maria Cantwell and Patty Murray have repeatedly pushed for more incentives for SAF, including a SAF-specific blender’s tax credit and increased federal funding for investments and research. And Gov. Jay Inslee and the state Legislature have jointly convened a Sustainable Aviation Biofuels Work Group – composed of dozens of universities, airlines and other companies, including Boeing – to promote development and adoption of these fuels.
These efforts and others will bring us closer to President Biden’s near-term goal of producing three billion gallons of biofuel a year by 2030. But that’s still less than one-thirtieth of annual consumption at the pre-pandemic peak. Much more investment and policy support will be necessary for the biofuel revolution to get off the ground.
As travelers return to airports, putting aviation on a more sustainable environmental course is imperative. Biofuels can help us find a way to a greener flying future.