Alcohol-to-Jet (ATJ): The SAF Pathway Built for the US Ethanol Advantage
- Jun 1
- 4 min read
Updated: Jun 2
How engineering directors and plant owners can leverage America's 17-billion-gallon ethanol industry to produce certified sustainable aviation fuel through the ATJ pathway.
Key Takeaway
Alcohol-to-Jet (ATJ) converts ethanol or isobutanol into certified SAF through dehydration, oligomerization, and hydroprocessing. It is the most practical pathway for US plant owners with access to the domestic ethanol supply chain. LanzaJet's Georgia plant proved out commercial scale ATJ in 2024. Production cost runs slightly above HEFA today but the feedstock ceiling that limits HEFA does not apply.
The Alcohol-to-jet (ATJ) Process: How Alcohol becomes Jet fuel
The alcohol-to-jet pathway starts with a fermentation-derived alcohol feedstock and converts it into jet range hydrocarbons through four main process steps. The pathway is certified under ASTM D7566 Annex A5.
Step | What Happens | Key Engineering Considerations |
1. Alcohol feed preparation | Ethanol or isobutanol is received, stored, and conditioned | Water content specification is critical; dehydration unit sizing |
2. Dehydration | Alcohol is dehydrated over a catalyst to produce olefins (ethylene or isobutylene) | Reactor temperature and pressure selection; catalyst lifetime management |
3. Oligomerization | Short chain olefins are linked together into jet range hydrocarbons (C8 to C16) | Selectivity to jet versus naphtha is determined here; licensor selection matters |
4. Hydrotreatment and fractionation | Olefins are hydrogenated to paraffins and fractionated into SAF, naphtha, and LPG cuts | Hydrogen consumption; heat integration; product yield optimization |
The Alcohol-to-jet (ATJ) Feedstock: Why the US Gulf coast has an advantage supplying SAF
The United States produces approximately 17 billion gallons of corn ethanol per year, making it the world's largest ethanol producer. Texas, Louisiana, and other Gulf Coast states have convenient access to Midwest ethanol via pipeline, rail, and barge. For a Gulf Coast ATJ plant, ethanol feedstock logistics are well understood and supply chains are mature.
Second generation cellulosic ethanol from agricultural residues such as corn stover, sugarcane bagasse, and energy crops offers even better carbon intensity scores under US 45Z rules and EU RED III, because the feedstock does not compete with food. Several US cellulosic ethanol producers are actively seeking ATJ co-development partners in 2026.
17Bn Gal | US corn ethanol production per year, making the US the largest ethanol producer globally. Source: USDA ERS. |
1.60-2.10 | USD per kg production cost for ATJ SAF in 2026, slightly above HEFA. Source: OIES December 2025. |
~70% | Energy yield from ethanol feedstock to jet fuel product in a typical ATJ plant. |
ATJ CAPEX and key cost drivers
Parameter | Typical Range | Notes |
CAPEX per tonne SAF capacity | 800 to 1,400 USD/tonne/year | Greenfield; co-location with ethanol plant reduces this |
Production cost | 1.60 to 2.10 USD/kg SAF | Feedstock cost is the primary variable; hydrogen is secondary |
Feedstock cost sensitivity | High | Every 50 USD/tonne change in ethanol price shifts production cost by roughly 0.10 USD/kg SAF |
Hydrogen consumption | 100 to 200 kg H2 per tonne SAF | Lower than HEFA because feedstock is already partially deoxygenated |
Typical FEED duration | 8 to 12 months | Longer than HEFA due to oligomerization reactor design complexity |
SAF yield from ethanol | Around 70 percent energy basis | Naphtha and LPG are valuable co-products |
ATJ Licensor Landscape in 2026?
Technology licensor selection is one of the most important decisions in an ATJ pre-FEED. The licensor provides the process guarantee that underpins lender confidence. Three technology providers have active ATJ licensing programs as of 2026.
LanzaJet has the most operating data from its Freedom Pines facility in Georgia and licenses the full ATJ process including oligomerization.
Honeywell UOP licenses the Ethanol-to-Jet process based on its established olefin processing technology portfolio.
Axens offers ATJ technology through its partnership with Total and has active licensing discussions in Europe and Asia.
How ATJ compares to HEFA for a Gulf Coast plant owner
Factor` | HEFA | ATJ |
Feedstock ceiling | Hard ceiling: UCO is scarce | Softer ceiling: ethanol market is large |
Feedstock cost sensitivity | High and rising | High but more stable |
Capital cost | Lower (esp. for revamps) | Moderate to high |
Carbon intensity scoring | Depends heavily on UCO origin | Better with cellulosic ethanol |
45Z credit eligibility | Yes, with traceable feedstock | Yes, especially with low CI ethanol |
FEED timeline | 6 to 9 months | 8 to 12 months |
Technology maturity | Very high | Early commercial but growing fast |
What the ATJ FEED scope typically covers?
RVN provides ATJ FEED and pre-FEED engineering from Houston, Texas, covering process simulation, heat and material balance, technology licensor evaluation, equipment sizing, and AACE Class 3 cost estimation. Our sustainable aviation fuel services page covers the full scope. ATJ projects that involve integration with an existing ethanol plant also draw on our petrochemical process engineering experience.
Frequently Asked Questions
Can any ethanol be used as ATJ feedstock?
Technically yes, but the choice of ethanol type significantly affects carbon intensity scoring and credit eligibility. Conventional corn ethanol meets the minimum threshold for ASTM D7566 Annex A5 certification. Cellulosic ethanol from agricultural residue or waste streams achieves better lifecycle carbon intensity scores, which matters for US 45Z and EU RED III qualification.
What is the minimum plant scale for an ATJ SAF plant?
Most ATJ plants are designed at 30,000 to 200,000 tonnes per year of SAF output. Below 30,000 tonnes, the capital cost per tonne becomes hard to justify. Co-location with an ethanol plant can improve economics at smaller scales by sharing utilities and reducing feedstock handling costs.
Is ATJ SAF accepted by all major airlines?
Yes. All SAF certified under ASTM D7566 Annex A5 is accepted by all commercial airlines operating Boeing and Airbus aircraft. The fuel is blended at the airport terminal and is transparent to aircraft operations.
About Author: Ragavan Vaidyanathan is a Chemical Engineer (Ph.D., Auburn University) with 25+ years leading capital projects up to $3B TIC across Power, Petrochemical, Refining, and Renewable Fuels. Former Sr. Director of Process Engineering at Jacobs/Worley, he now leads RVN Inc., delivering high-value engineering solutions from Houston, TX. About RVN: RVN Inc. is a Houston-based engineering firm specializing in pre-FEED, FEED, detailed engineering, and AACE Class 3 cost estimation for capital projects across the Power, Petrochemical, Polymer, Refining, and Renewable Fuels industries. With a global network of high-value engineering centers, RVN delivers rigorous technical execution — from process design through commissioning — for clients navigating complex, large-scale energy transitions including Sustainable Aviation Fuel. 📩 To learn more or discuss your SAF project, contact us at admin@rvninc.com |
Sources
OIES. Drop In Decarbonization: SAF Techno-Economic Benchmark. December 2025.
IATA. SAF Handbook. May 2024. iata.org
US DOE Bioenergy Technologies Office. SAF Grand Challenge. energy.gov
ResourceWise. 2026 SAF Market Outlook. resourcewise.com