In a little more than a decade, the use of biofuels in commercial aircraft has gained critical ground.
By Paul McElroy, Boeing Writer
It began in fall 2006, when a group in the United Kingdom called Plane Stupid staged protests criticizing short-haul flights—part of a chorus of environmental protests across Europe urging people to stop flying.
Boeing heard the message. And against that backdrop, it began developing a comprehensive environmental strategy, which included sustainable aviation fuel as a new way to reduce life-cycle carbon dioxide emissions from airplanes by up to 80 percent.
Aided by Boeing’s technical expertise, Virgin Atlantic flew the world’s first airline biofuel test flight on a 20 percent blend made from coconut and babassu oil in one fuel tank of a 747-400 from London to Amsterdam on Feb. 24, 2008.
Boeing then supported three more test flights with Air New Zealand, Continental and Japan Airlines to gain certification of biofuels for commercial use. The airplanes were equipped with engines from CFM, Pratt & Whitney and Rolls-Royce to gather broader results. The fuel, derived from waste animal fats, was called HEFA (for hydro-processed fatty acid esters and free fatty acids).
Fast-forward a decade, and Boeing began offering customers the option of powering their commercial airplane delivery flights with sustainable aviation fuel to spur its use and support the industry’s drive to protect the environment.
“This is another step in our journey to encourage the adoption of sustainable fuels and help commercial aviation earn its license to keep growing,” said Sheila Remes, who leads Boeing Commercial Airplanes strategy.
When it takes delivery of its first three Boeing 737 MAX airplanes, Alaska Airlines, the first participant in the initiative, plans to fly them on a blend of biofuel and traditional jet fuel to its hub at Seattle-Tacoma International Airport.
Boeing is offering biofuel to customers accepting new airplanes at its delivery centers in Seattle and Everett, Washington, as well as using biofuel for certain flight-test operations at Boeing Field in Seattle.
In January, Etihad Airways became the latest operator to demonstrate the viability of biofuels by flying the world’s first passenger flight using sustainable fuel made from a plant that grows in saltwater. The flight from Abu Dhabi to Amsterdam on a 787-9 Dreamliner culminated a three-year research project supported by Etihad, Boeing and several other organizations.
The United Arab Emirates project seeks to develop aviation biofuel to reduce carbon dioxide emissions and lessen the country’s need to import nearly 85 percent of its food. Fish raised at a unique aquaculture farm in the UAE fertilize the plant and provide food for the desert nation.
“The technology shows significant promise to transform coastal deserts into productive farmland supporting food security and cleaner skies,” said Sean Schwinn, Boeing International vice president of strategy and market development.
Sustainable aviation fuel progressed from the first Virgin Atlantic test flight in 2008 to everyday use in less than a decade—with Boeing playing a leadership role in its birth and growth. Test flights, research and rigorous reviews by airlines, airplane and engine manufacturers, refiners, regulators and others led to HEFA’s certification for commercial use in July 2011.
“It was very challenging because no one had created a biologically based aviation fuel before,” said Jim Kinder, Boeing Senior Technical Fellow, who is an expert in aviation fuels. “But we knew it would work. In fact, biofuel has a higher energy density and performs better than Jet A.”
An early decision by stakeholders proved key, Kinder said. “Biofuels have to be drop-in. That way, they can be blended directly with fossil fuel without modifying the airplane, its engines or airport fueling systems.”
After HEFA’s certification, various airlines began flying passenger flights using a blend of biofuel and traditional fuel to demonstrate their environmental commitment and market interest. Starting in 2015, several operators bought nearly 1.7 billion gallons of biofuel to use over the next five years. Norway’s Oslo Airport became the first in the world to regularly offer it to all departures in 2016—followed by Los Angeles, Stockholm and Bergen, Norway.
Around the time of Virgin’s pioneering flight, industry leaders, including Boeing and Airbus, voluntarily set three goals to reduce commercial aviation’s 2 percent share of global emissions: Improve fuel efficiency by 1.5 percent annually from 2009 to 2020; stop the growth of emissions next year; and cut them to half of what they were in 2005 by 2050.
In the decade following that flight, global air travel doubled to more than 4 billion passengers annually. Airlines have been modernizing their fleets, however, and the industry has taken other steps to improve operational efficiency— enabling aviation to exceed its 1.5 percent goal.
But those 12 million people a day who fly now are expected to double again in 20 years, according to industry estimates. The growth in emissions poses a challenge to achieving the other goals. And as evidence of climate change increases, anti-flying sentiment has surged anew.
As a prelude to its technical work, Boeing started collaborating with industry stakeholders on regional roadmaps to develop biofuel. The first initiative involved partnerships with Alaska Airlines; the ports of Seattle and Spokane, Washington, and Portland, Oregon; Washington State University; and others to create a group called Sustainable Aviation Fuels Northwest.
That effort became a blueprint. Boeing has worked with several dozen partners around the world since then to develop similar roadmaps for processes meeting strict third-party sustainability certifications. Feedstocks have included Brazilian sugarcane, a nicotine-free tobacco plant grown in South Africa and the unique ecosystem in the UAE that creates biofuel from desert plants irrigated with seawater, among others.
“We’re catalyzing supplies tailored to regional resources, which can be scaled commercially at prices competitive with traditional jet fuel,” said Sean Newsum, who directs the environmental strategy for Boeing Commercial Airplanes. “Some production pathways have the added benefit of reducing other types of pollution, such as making biofuel from household waste and carbon captured in industrial off-gassing.”
Boeing is also working to gain certification for HEFA+. Called green diesel in ground transportation, certification would make a price-competitive, sustainable supply available that could meet more than 1 percent of global aviation needs.
“I think we’re nearing a tipping point,” Newsum said.