Aug-2021

Sustainable aviation fuel comes of age

Sustainable aviation fuels have been under development for more than a decade at Neste, and the company believes an uptick in demand is imminent

Arne Padt
Neste

Article Summary

Aviation is an industry built on cooperation and responsibility. Its actors have a history of coming together to agree on standards and procedures that keep passengers and freight moving safely around the world.

In recent years, the industry has taken some important shared steps to address its environmental impact. At pre-pandemic levels, aviation produced some 2.5% of all carbon dioxide (CO2) emissions. Acknowledging this, the aviation industry has committed to carbon-neutral growth from 2020, and a 50% reduction in net emissions by 2050 (from 2005 levels).

A key element in achieving these targets is the wider introduction of sustainable aviation fuel (SAF) made from waste and residue raw materials. These sustainable fuels are blended with traditional jet fuels for a lower environmental footprint per flight.

The SAF industry has been quietly growing since the late 2000s through infrastructure investment and hundreds of test flights. More recently, critical changes in national regulations have given the industry a significant boost.

Early standards, first movers
The SAF industry was born around 2006 with the formation of the Commercial Aviation Alternative Fuels Initiative (CAAFI) in the United States. Today, CAAFI is one of the industry’s main bodies, a public-private partnership that drives the development of alternative jet fuels through its member airlines, aircraft and engine manufacturers, policymakers and companies like Neste.

The first SAF standard was approved in 2009 through the international standards organisation ASTM. Today, there are seven ASTM-certified pathways available for SAF production. Depending on the pathway, the fuels may be made from a variety of raw materials, including used cooking oils, animal waste fats, and different agricultural and forestry residues. Standardisation rules require that sustainable jet fuel can be blended with conventional jet fuel at a ratio of up to 50%.

Henrik Erämetsä, Neste Senior Advisor for Renewable Aviation Regulation, has been involved since the industry’s early days.

“In the beginning, nobody knew how to approach the issue of standardizing sustainable aviation fuel,” says Erämetsä.

“Through ASTM, the industry was able to agree that it needs to be a ‘drop-in fuel’. In other words, all legacy airliners need to be able to use the fuel — it cannot be developed only with future aircraft in mind. Neste participated in this standardization development work from the start.”

There are environmental benefits to SAF that go beyond the reduction in carbon emissions. Exhaust fumes from traditional jet fuel also include non-CO2 emissions such as nitrogen oxides and particulates. But sustainable jet fuel contains no sulphur or aromatics and therefore burns in a cleaner way with fewer sulphur oxides and particle emissions. This also means a reduction in aircraft contrails — the white wake we sometimes see behind aircraft as they pass high overhead. Estimates indicate that as much as two-thirds of a flight’s environmental impact is caused by non-CO2 emissions, such as the soot particles in contrails.

Vision-driven investment
Neste produced its initial SAF in 2011, delivering to Lufthansa for the world’s first long-term test. SAF from Neste was used more than 1200 times on twin-turbine aircraft between Frankfurt and Hamburg.

“Lufthansa used regular jet fuel in one of the engines and our fuel in the other. Their main finding was that there is no difference other than the energy content of the fuel. Everything worked the same as with fossil jet fuel,” says Erämetsä.

Since those early days — through dedicated investment and persistence — Neste now has the capacity to refine 100,000 t/y of SAF at its Porvoo site in Finland. With an expansion of its Singapore refinery already under way and an extra investment in its Rotterdam site, the company will have the capacity to produce some 1.5 million t/y of SAF by the end of 2023.

In addition to Lufthansa, the company’s customers now include Alaska Airlines, American Airlines, ANA, Finnair, KLM, and several other airlines. Neste SAF is available at multiple major international airports, such as San Francisco and Schiphol. The company is also working with Shell, BP and others to expand its reach further.

“It’s been a long journey for Neste,” says Sami Jauhiainen, Vice President Renewable Aviation.

“Getting the waste and residue raw material for biofuels requires partnerships and a large aggregation network. It’s very fragmented, so we’ve done a lot of work on sourcing the material. We’ve also been continuously investing in our pre-treatment processes so that we have the capability to refine lower and lower quality raw materials into SAF.”

Last year, Neste acquired US-company Mahoney Environmental — a leading collector and recycler of used cooking oil. The acquisition follows that of Dutch animal-fat trader IH Demeter in 2018.

Jauhiainen says a big milestone for the industry came around 2015 through an EU-funded project called the Initiative Towards sustAinable Kerosene for Aviation (ITAKA). The project brought about the first use of an underground hydrant system — instead of a truck — to bring SAF to aircraft at Oslo’s Gardermoen Airport.
“The standards have set a 50% maximum for SAF, so it always needs to be mixed with fossil jet fuel before being brought to the airport,” says Jauhiainen.

“Fundamentally, though, there are no limitations to using SAF in higher quantities in modern aircraft, so this is a focus area for many leading OEMs. Boeing has even set a target that in 2030 its planes will be able to use only sustainable fuel.”

Neste has also teamed up with Airbus, German research centre DLR and jet-engine manufacturer Rolls-Royce to start the pioneering ‘Emission and Climate Impact of Alternative Fuels’ (ECLIF3) project, looking into the effect of using 100% SAF.

New regulations drive change
Although standards for aviation biofuels have been in place for more than a decade, the SAF industry has progressed at a much slower pace than the transition to biofuels in road transportation. Jauhiainen says this is due to limited pressure and incentives from policy that would move the industry in the right direction.