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Neste and American Airlines collaborate to explore opportunities for renewable fuel use; High Freeze Point HEFA

Neste, the world’s leading producer of renewable diesel, and American Airlines, the world’s largest airline, have entered into an agreement to explore opportunities to further reduce American’s environmental footprint through the use of Neste’s renewable fuels. One goal of the cooperation will be complementary efforts to facilitate acceptance and commercialization of High Freeze Point HEFA (HFP-HEFA) renewable jet fuel (Also called HEFA+), which is currently under consideration for approval by ASTM International.

In 2015, Neste and Boeing announced they would work together toward ASTM International fuel standard approval allowing the commercial use of HFP-HEFA renewable aviation fuel by airlines, with the ultimate goal of accelerating adoption of renewable aviation fuel by establishing a standard that, while reducing the maximum blend level acceptable, also relaxes the processing requirements and increases the yield of the renewable fuel. (Earlier post.)

ASTM’s specification for aviation fuel containing synthesize hydrocarbons (ASTM D7566) includes annexes dealing with different types of synthetic jet fuel. Annex A1 handles Fischer-Tropsch (FT) synthesized paraffinic kerosene (SPK) (50% max blend); Annex A2, hydroprocessed fatty acid esters and fatty acids (HEFA) (50% max blend); Annex 3, SIP (synthesized isoparaffins) (10% max blend); Annex 4, Fischer Tropsch synthesized paraffinic kerosene with aromatics (SPK/A) (50% max blend); and Annex 5, alcohol to jet (ATJ) (30% max blend).

In a 2016 open-access paper published in the journal Oil & Gas Science and Technology, Starck et al. explain the attraction of HFP HEFA:

One of the major steps limiting the process yield for HEFA remains the isomerisation that allows production of a biofuel with very good cold flow properties. But this step introduces a substantial decrease of the overall yield (fuel component per kg of starting material) due to the production of light compounds, unsuitable for conventional jet fuel. In this work relaxing the freezing point requirement for the neat HEFA component (by decreasing the severity of the isomerisation step) is proposed in order to minimize the production of less valuable light compounds. This strategy could lead to a significant additional biofuel yield with respect to the oil compared to a process making a better freeze point component. This allows the land surface area necessary for HEFA feedstock cultivation to be reduced for a given amount of bio-jet fuel produced.

Boeing has successfully tested Neste’s HFP HEFA in a 15% blend in Boeing’s 787 ecoDemonstrator. Fifteen percent is the estimated blend maximum for HFP HEFA, as compared to 50% for HEFA.

Together, Neste and American Airlines are evaluating in-flight and on-the-ground opportunities for mutually beneficial cooperation and collaboration. We share a common view that innovative low-carbon solutions are needed to help the aviation industry meet its greenhouse gas emission reduction goals, and renewable jet fuel is an important part of the solution.

—Kaisa Hietala, Neste's Executive Vice President of Renewable Products

The aviation industry has set targets to mitigate greenhouse gas emissions from air transportation, including carbon-neutral growth from 2020 and beyond, and a 50% reduction of net aviation CO2 emissions by 2050. Currently, sustainable renewable jet fuel offers the only viable alternative to fossil liquid fuels for powering commercial aircraft.

American Airlines has already taken steps to reduce its carbon footprint with its ambitious fleet renewal program. By the end of 2017, American will have invested more than $18 billion and introduced 496 new aircraft into its fleet since the merger with US Airways, while retiring 469 older aircraft—giving American the youngest fleet of the US network carriers.


  • Laurie Starck, Ludivine Pidol, Nicolas Jeuland, Thierry Chapus, Paul Bogers and Joanna Bauldreay (2016) “Production of Hydroprocessed Esters and Fatty Acids (HEFA) – Optimisation of Process Yield” Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles doi: 10.2516/ogst/2014007



The real news in the airline industry is Airbus' continuing development of electric and hybrid powered aircraft. Small aircraft right now; but, their plans for the future include point to point passenger aircraft. The down side is Airbus predicts they will require batteries with at least 400 Wh/Kg density. We all would love to have that and many are looking at Lithium metal batteries as opposed to lithium ion batteries as the solution.

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