Sustainable fuel sources

United eco-skies United eco-skies United eco-skies

While aviation accounts for only two percent of global CO2 emissions, we recognize that climate change is a significant global concern. We’ve improved our fuel efficiency by 45 percent since 1990, but that’s only the first step.

Chart – Our commitment to biofuels United has 55 percent of the airline industry’s current biofuel commitments with our partnerships with AltAir Fuels and Fulcrum BioEnergy. Cathay Pacific follows with their partnership with Fulcrum BioEnergy with about one quarter of the industry’s current biofuel commitments, followed by all other airlines. Chart – Our commitment to biofuels United has 55 percent of the airline industry’s current biofuel commitments with our partnerships with AltAir Fuels and Fulcrum BioEnergy. Cathay Pacific follows with their partnership with Fulcrum BioEnergy with about one quarter of the industry’s current biofuel commitments, followed by all other airlines. Chart – Our commitment to biofuels United has 55 percent of the airline industry’s current biofuel commitments with our partnerships with AltAir Fuels and Fulcrum BioEnergy. Cathay Pacific follows with their partnership with Fulcrum BioEnergy with about one quarter of the industry’s current biofuel commitments, followed by all other airlines.
Together with other airlines, engine and airframe manufacturers, fuel suppliers, airports and governments, we’re working towards a collective industry goal of 1.5 percent average improvement of annual fuel efficiency through 2020, carbon neutral growth beginning in 2020 and a 50 percent reduction in airline CO2 emissions by 2050.


While aviation accounts for only two percent of global CO2 emissions, we recognize that climate change is a significant global concern. We’ve improved our fuel efficiency by 45 percent since 1990, but that’s only the first step.

Together with other airlines, engine and airframe manufacturers, fuel suppliers, airports and governments, we’re working towards a collective industry goal of 1.5 percent average improvement of annual fuel efficiency through 2020, carbon neutral growth beginning in 2020 and a 50 percent reduction in airline CO2 emissions by 2050.

Investing in sustainable aviation fuels is our way of continuing to operate a more sustainable airline. This investment is not only good for the environment, but also has the potential to guard against future oil price instability while creating clean energy jobs in the communities we serve.

Learn more

Our partners

At United, we're excited about the innovation that sustainable aviation fuels bring to the airline industry. As a leader in advancing these fuels, we’re actively working with strategic partners to generate sustainable aviation fuels capable of reducing our CO2 emissions and providing energy diversification.

In recognition of our work in this area, United was named a “Leading Airline” by the Natural Resources Defense Council (NRDC) for having a strong range of commitments and supply chain implementation.

A timeline of firsts

Over the past decade, United has led the U.S. airline industry in sustainable aviation fuels. Here are some of our firsts:

Infographic, a timeline of firsts. 2009, United ran the first alternative fuel test flight using fuel derived from algae. 2011, The first commercial flight powered by advanced biofuel takes off with United. 2013, United partakes in the first commercial-scale supply agreement for sustainable aviation biofuel 2015, United invests in Fulcrum BioEnergy, becoming the first U.S. airline to invest in a biofuels company. 2016, United becomes the first U.S. airline to use renewable biofuel for regularly scheduled flights. Infographic, a timeline of firsts. 2009, United ran the first alternative fuel test flight using fuel derived from algae. 2011, The first commercial flight powered by advanced biofuel takes off with United. 2013, United partakes in the first commercial-scale supply agreement for sustainable aviation biofuel 2015, United invests in Fulcrum BioEnergy, becoming the first U.S. airline to invest in a biofuels company. 2016, United becomes the first U.S. airline to use renewable biofuel for regularly scheduled flights. Infographic, a timeline of firsts. 2009, United ran the first alternative fuel test flight using fuel derived from algae. 2011, The first commercial flight powered by advanced biofuel takes off with United. 2013, United partakes in the first commercial-scale supply agreement for sustainable aviation biofuel 2015, United invests in Fulcrum BioEnergy, becoming the first U.S. airline to invest in a biofuels company. 2016, United becomes the first U.S. airline to use renewable biofuel for regularly scheduled flights.

AltAir Fuels

In 2016 United became the first airline globally to fly on sustainable aviation fuel on an ongoing, daily basis. The fuel is supplied to our Los Angeles hub by AltAir Fuels. Using technology from Honeywell UOP, AltAir retrofitted a refinery in Paramount, California, into an advanced biofuel facility that converts feedstock, such as agricultural wastes and non-edible natural oils into low-carbon advanced biofuels

In early 2018, AltAir’s fuel obtained sustainability certification from the Roundtable for Sustainable Biomaterials. AltAir’s fuel meets the same industry standard as petroleum-based products while reducing greenhouse gas (GHG) emissions by greater than 60 percent. In addition, the use of waste and residue materials are a crucial part of AltAir’s feedstock mix as their use reduces the pressure on land and natural resources which are pivotal factors in the development of a truly sustainable bioeconomy.

Infographic – AltAir and United: By the numbers 15 million, gallons of biofuel United will purchase from AltAir over a three-year period. 2016, United made history in March 2016 with the first, ongoing supply of biofuels from AltAir Fuels 65, the number of jobs created in Paramount, California, by the opening of the AltAir refinery 60 plus, the percent reduction in greenhouse gas emissions that AltAir biofuel provides when compared to traditional jet fuel. 30, percentage of biofuel that’s mixed with traditional jet fuel. Infographic – AltAir and United: By the numbers 15 million, gallons of biofuel United will purchase from AltAir over a three-year period. 2016, United made history in March 2016 with the first, ongoing supply of biofuels from AltAir Fuels 65, the number of jobs created in Paramount, California, by the opening of the AltAir refinery 60 plus, the percent reduction in greenhouse gas emissions that AltAir biofuel provides when compared to traditional jet fuel. 30, percentage of biofuel that’s mixed with traditional jet fuel. Infographic – AltAir and United: By the numbers 15 million, gallons of biofuel United will purchase from AltAir over a three-year period. 2016, United made history in March 2016 with the first, ongoing supply of biofuels from AltAir Fuels 65, the number of jobs created in Paramount, California, by the opening of the AltAir refinery 60 plus, the percent reduction in greenhouse gas emissions that AltAir biofuel provides when compared to traditional jet fuel. 30, percentage of biofuel that’s mixed with traditional jet fuel.

Fulcrum BioEnergy

In 2015, United signed the largest sustainable aviation fuel commitment in aviation history when we partnered with Fulcrum BioEnergy, a company that has pioneered technology for converting waste and household trash into low-cost, sustainable aviation fuel.

We are working with Fulcrum to develop sustainable aviation fuel refineries located near our U.S. hubs. When built, these refineries will produce nearly one billion gallons of sustainable aviation fuel for United in their first ten years of operation. That’s nearly three times the amount of fuel United uses every year.

Our agreement with Fulcrum will reduce our carbon footprint, divert waste from landfills and create new jobs at the Fulcrum facilities located in the communities that support our hubs.

From trash to takeoff

Here’s how your ordinary household trash will avoid the landfill and power our planes.

Infographic – from trash to takeoff Step 1, trash collection. Trash is collected and delivered to a Fulcrum facility. Step 2, trash processed. The trash is processed, recyclables are removed and the rest goes to the refinery. Step 3, Fulcrum BioEnergy. The refinery converts trash to a drop-in sustainable aviation biofuel meeting United’s technical requirements. Step 4, Clean fuel. Biofuel is transported to the airport supply where it is blended with traditional jet fuel. Step 5, in the air. Sustainable aviation biofuel from Fulcrum produces 80 percent fewer greenhouse gas emission than traditional fuel on a lifecycle basis. Infographic – from trash to takeoff Step 1, trash collection. Trash is collected and delivered to a Fulcrum facility. Step 2, trash processed. The trash is processed, recyclables are removed and the rest goes to the refinery. Step 3, Fulcrum BioEnergy. The refinery converts trash to a drop-in sustainable aviation biofuel meeting United’s technical requirements. Step 4, Clean fuel. Biofuel is transported to the airport supply where it is blended with traditional jet fuel. Step 5, in the air. Sustainable aviation biofuel from Fulcrum produces 80 percent fewer greenhouse gas emission than traditional fuel on a lifecycle basis. Infographic – from trash to takeoff Step 1, trash collection. Trash is collected and delivered to a Fulcrum facility. Step 2, trash processed. The trash is processed, recyclables are removed and the rest goes to the refinery. Step 3, Fulcrum BioEnergy. The refinery converts trash to a drop-in sustainable aviation biofuel meeting United’s technical requirements. Step 4, Clean fuel. Biofuel is transported to the airport supply where it is blended with traditional jet fuel. Step 5, in the air. Sustainable aviation biofuel from Fulcrum produces 80 percent fewer greenhouse gas emission than traditional fuel on a lifecycle basis.

Biofuels FAQs

  • The difference is in the source material, or feedstock. Whereas conventional jet fuel is derived from crude oil, sustainable aviation biofuels can be derived from sources like non-edible natural oils and agricultural wastes. The Federal Aviation Administration has deemed this fuel as acceptable for use on aircraft, provided it meets ASTM specifications. AltAir is pursuing certification under the Roundtable on Sustainable Biomaterials (RSB) - a global sustainability standard and certification system that recognizes biomass and biofuel producers that adhere to strict social responsibility and environmental criteria.

  • Sustainable aviation biofuels can benefit the environment by significantly reducing the amount of CO2 emissions produced during the "lifecycle" of that fuel compared to conventional jet fuel. "Lifecycle" refers to all emissions produced during the entire process, from extracting or collecting the feedstock to refining, transporting and using the fuel.

  • Yes, there have been thousands of flights using biofuel like that produced by AltAir, including flights using the same Honeywell UOP's Green Jet Fuel™ process. The fuel from AltAir meets the same stringent international fuel certification as conventional jet fuel (ASTM Standard D-1655), and the Federal Aviation Administration has deemed this fuel as acceptable for use on aircraft provided it meets ASTM specifications. Because this fuel is considered a "drop in" fuel, no infrastructure or aircraft engine modifications are necessary. Passengers won't notice any difference when flying on an aircraft using 100 percent petroleum fuel or one using a biofuel blend, as both types meet the same technical and safety requirements.

  • This launch is a milestone in the U.S. commercial aviation industry because it moves biofuel use beyond demonstration flights and pilot programs and into our ongoing commercial operations. The 15 million gallons of biofuel we plan to purchase from AltAir is integrated with our total fuel supply chain at Los Angeles. It’s enough fuel to power the equivalent of 12,500 flights from Los Angeles to San Francisco.

  • There is currently no way to purchase tickets specifically for a flight powered by biofuel. Our long-term goal is to expand the use of cost-competitive, commercial-scale aviation biofuel to many other locations. We anticipate that our agreements with AltAir Fuels and Fulcrum Bioenergy will bring millions of gallons of sustainable aviation biofuel to more of the airports that we serve in the years to come.

  • First, you can travel with airlines like United that are working to reduce the carbon intensity of flying by making significant fuel efficiency improvements and by increasing their use of biofuels. United customers can purchase carbon offsets or donate miles towards the purchase of carbon offsets through our Eco-Skies CarbonChoice program, which also enables our customers to offset their United air travel and cargo shipments for their entire enterprise.