How ethanol derived jet fuel won approval

The US Department of Energy’s Pacific Northwest National Laboratory (PNNL) and its industrial partner LanzaTech claim that their new technology is helping clear the way to ethanol derived jet fuel.

In April, the ASTM International revised ASTM D7566 Annex 15 – the Standard Specification for Aviation Turbine Fuel Containing Synthesised Hydrocarbons – to add ethanol as an approved feedstock for producing alcohol-to-jet synthetic paraffinic kerosene (ATJ-SPK).

According to a statement, combined research between PNNL and LanzaTech was vital to securing this approval for jet fuel from ethanol.

Through an eight year research project, PNNL developed a thermocatalytic process for converting ethanol into ATJ-SPK. The multistage process starts with the conversion of ethanol into ethylene (dehydration). The second stage (oligomerization) chemically combines ethylene molecules to build the range of hydrocarbon molecules needed for aviation fuel. The hydrocarbons are then hydrogenated, followed by fractionation to produce alcohol-to-jet synthetic paraffinic kerosene with the desired properties.

The process can use ethanol from any source.

PNNL and LanzeTech worked together to scale up the catalyst, with the US company successfully producing 4,000 gallons of ethanol-derived ATJ-SPK. LanzaTech compiled data from extensive analysis and testing of the ATJ-SPK, which was submitted to the Federal Aviation Administration for a review, a process that culminated in the revisions to ASTM standards.

"Commercial airlines consume a lot of fuel, and it is a major contributor to their costs. Sustainable aviation fuel offers airlines another option, which has benefits for the environment and offers a hedge against swings in oil prices," said Corinne Drennan, sector lead for bioenergy technologies at PNNL.

"ASTM qualification of ATJ-SPK at a 50 percent blend ratio is a significant step forward. In theory, half the fuel powering commercial airlines could come from ethanol-derived fuel. We look forward to advancing the technology to bring down production costs and further improve the carbon intensity of sustainable aviation fuels from ethanol."

ASTM International develops standards across the globe for a variety of industries, including aviation.

“ASTM qualification of ethanol derived jet fuel means that where there is sustainable ethanol we have the potential to produce low carbon jet fuel" said Jennifer Holmgren, chief executive officer of LanzaTech.

"The scale of production is what matters, and the inclusion of ethanol in ASTM D7566 Annex A5 is, therefore, hugely significant as it means we can access large volumes of sustainable ethanol feedstock globally to support the aviation sector's decarbonisation targets."