Decarbonisation Technology August 2025 Issue

Alcohol-to-Jet technology process

Step

Input

Output

Purpose

Dehydration

Ethanol Ethylene

Ethylene

Remove water to create reactive olefins Build jet-fuel-range hydrocarbons Stabilise and saturate hydrocarbons Isolate SAF and renewable diesel

Oligomerisation Hydrogenation Fractionation

Long-chain olefins Paraffins (alkanes)

Olefins

Hydrocarbons

Fuel

Table 1 ATJ technology process draws on principles from traditional oil and gas refining, such as catalytic conversion, distillation, and hydrogenation, to transform alcohols into jet-range hydrocarbons

the airline industry’s emission reduction strategy is largely dependent on a suite of green, breakthrough, first-of-a-kind (FOAK) technologies to deliver its all-important net-zero 2050 goal. In turn, the industry has been on the lookout for pioneering companies seeking to successfully deliver the next commercially scaled SAF production pathway. LanzaJet’s Alcohol-to-Jet (ATJ) solution is a fully certified SAF pathway, leveraging ethanol as its input, which can be produced from virtually any form of non-fossil, hydrocarbon waste stream. From laboratory innovation to commercial reality The inception of LanzaJet’s ATJ technology dates back to a collaboration between LanzaTech, the US Department of Energy, and the Pacific Northwest National Laboratory in 2010. This partnership yielded a catalytic process capable of converting ethanol into SAF, representing a pivotal advancement in aviation’s energy transition aspirations. Given its similarity to the process of producing alcohol, the industry accredited the ethanol pathway with the official name of ‘Alcohol-to-Jet’ or ‘ATJ’. Building upon this foundational technology, LanzaJet was spun out of LanzaTech in 2020 as an independent company, with the specific aim of specialising in, commercialising, and globally scaling the ATJ SAF pathway. The company’s first major milestone was in August 2024, when LanzaJet’s Freedom Pines Fuels facility in Soperton, Georgia (USA) celebrated its mechanical completion (see Figure 2 ). In doing so, the 37 million litre (10 million gallon) plant also became the world’s first refinery to position itself as a non-oil-based drop-in fuel solution for the airline industry. This facility seeks to demonstrate the practical application of ATJ

technology by utilising a range of low-carbon ethanol sources and converting these into SAF. Alcohol-to-Jet technology LanzaJet’s technology is split into four discrete processes, which enable the end-to-end conversion of any ethanol source into a drop-in commercial SAF blending component.  Dehydration What happens: Ethanol (C₂H₅OH) is dehydrated over a catalyst to form ethylene (C₂H₄). This serves as the foundational step, producing a hydrocarbon from which longer carbon chains suitable for jet fuel application can be formed. Water is also formed in this process as a byproduct. Chemical reaction: C₂H₅OH → C₂H₄ + H₂O  Oligomerisation What happens: The ethylene molecules (C₂H₄) are then brought into contact under conditions that build olefins in the C8-C16 range needed for jet fuel. Catalyst reaction (simplified): C₂H₄ → C₄H₈, C₆H₁₂, C₈H₁₆, etc.  Hydrogenation What happens: These longer chain olefins (alkenes) are then treated with hydrogen over catalyst, which saturates the olefins to form paraffins (alkanes). This helps to improve stability, reduce reactivity, and meet jet fuel specifications. Chemical reaction: CnH₂n (alkene) + H₂ → CnH₂n+2 (alkane)  Fractionation What happens: The alkanes, now in the form of a hydrocarbon mixture of varying chain