In Washington state, ASTM International recently revised ASTM D7566 Annex A5 — the Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons — to add ethanol as an approved feedstock for producing alcohol-to-jet synthetic paraffinic kerosene (ATJ-SPK). The revision of ASTM D7566 Annex A5 clears the way for increased adoption of sustainable aviation fuels because ethanol feedstocks can be made from so many different low-cost sources. Behind this significant advancement is the Department of Energy’s Pacific Northwest National Laboratory technology — eight years in the making — and its industrial partner, LanzaTech.
Using its expertise in chemistry and catalysis, PNNL developed a unique thermocatalytic process for converting ethanol into ATJ-SPK. The first step of the process is to convert the ethanol into ethylene (“dehydration”). During the second step (“oligomerization”), ethylene molecules are chemically combined to build the range of hydrocarbon molecules needed for aviation fuel. These 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, including ethanol produced via LanzaTech’s proprietary gas-to-ethanol process.