Sep-2024

Taking the SAF route to aviation sustainability (RI 2024)

Aviation accounts for 1.9% of overall greenhouse gas (GHG) emissions, making it an important pain point for policymakers and consumers alike in the drive towards decarbonisation

Leigh Abrams
Honeywell UOP

Article Summary

Aviation accounts for 1.9% of overall greenhouse gas (GHG) emissions, making it an important pain point for policymakers and consumers alike in the drive towards decarbonisation.¹ Climate action is becoming more codified by governmental initiatives and regulations.

For example, the European Council released its ReFuelEU Aviation rules as part of the ‘Fit for 55’ package, aiming to increase the sustainable fuels share at EU airports from a minimum of 2% in 2025 to 70% by 2050, with an additional sub-target for eSAF of 1.2% by 2030 and 35% by 2050.²

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), which is part of the United Nations’ International Civil Aviation Organization (ICAO), stipulates SAF as one of its eligible measures.³,⁴ Following technical analysis of lower-carbon aviation fuels, ICAO has stated that “SAF has the greatest potential to reduce CO₂ emissions from International Aviation”.⁵

Investment targets
The US’s Inflation Reduction Act (IRA) reduces the cost of clean hydrogen production by almost half and contributes to almost $369 billion dollars being made available to address energy security.⁶

Echoing the EU’s ‘Fit for 55’ package, the UAE’s Minister of Energy and Infrastructure has set a target of producing 700 million litres of SAF annually by 2030, and sees positive incentives as a critical tactic for achieving that growth.⁷ Meanwhile, in 2021, the Biden Administration announced its Sustainable Aviation Fuel Grand Challenge for the US aviation fuel supply sector to produce at least three billion gallons of SAF per year by 2030 and 35 billion gallons of SAF per year by 2050.⁸

Renewable jet fuel
The Ecofining™ process for renewable jet fuel is based on refinery hydroprocessing technology. The process produces a bio-synthetic paraffinic kerosene (bio-SPK) or renewable diesel, which is then blended with standard jet fuel for use in flight. With incentives available today in the US, even marginal improvements in distillate yield provide a substantial economic benefit.

At a 10,000 BPD feed rate, for example, a 1 wt% yield advantage is worth approximately $6 million in profits annually. Moreover, our experience with many types of sustainable feedstocks means we can guarantee catalyst cycle lengths based on actual operating data. The value of avoiding a five-day shutdown for catalyst reload is worth approximately $8 million in revenue for a 10,000 BPD unit.⁹

Single-stage Ecofining technology, enabling renewable diesel production, is ideal for refinery retrofits. A retrofit initiative typically costs 50-70% less than a greenfield project and can be completed in an average of 12-18 months, setting the stage for a straightforward expansion to two-stage processing for renewable jet fuel, which can be implemented later.¹⁰ With these types of assets, the Honeywell UOP ethanol-to-jet (ETJ) technology has been developed for ethanol producers looking for diversification to satisfy the needs of the aviation market.

Low-carbon SAF
eFining™ technology is a methanol-to-jet fuel (MTJ) processing technology that can convert eMethanol to eSAF reliably and at scale. eSAF belongs to a class of fuels called e-fuels, combining renewably manufactured green hydrogen with CO₂ to produce eMethanol. As a highly integrated design that can process flexible feedstocks using commercially proven processes, the technology results in high-yield eSAF production while reducing GHG emissions by 88% compared to conventional jet fuel.¹¹

Since 2011, millions of gallons of SAF have been produced using Honeywell UOP technology that meets ASTM D7566 specifications. This includes the fuel used for the world’s first transatlantic flight powered entirely by SAF.¹² SAF can be produced from a variety of sustainable feedstocks, including vegetable oils, animal fats, non-food-based fats, second-generation feedstocks such as camelina, jatropha and algae, and low-carbon- intensity alcohols.

GHG reduction by 70%
When blended up to 50% with petroleum-based jet fuel, SAF offers significant advantages over traditional fuel, such as with its higher energy density in flight allows aircraft to fly farther on less fuel. That means it offers a drop-in replacement fuel that requires no changes to aircraft technology or fuel infrastructure.¹³

Honeywell’s Fischer-Tropsch (FT) Unicracking™ technology converts FT liquids and waxes from agricultural, municipal, and forestry waste, in addition to biogas and CO2 combined with H2 to FT Synthetic Paraffinic Kerosene (FT-SPK), which is a form of ASTM D7666-approved SAF.

Honeywell UOP was recently awarded by DG Fuels with the largest announced FT-hydrocracker unit in the world to date, producing 13,000 BPD of SAF. The plant has an expected start-up in 2028 and will be located in Louisiana, USA. This also marks the first joint project with Johnson Matthey and BP’s co-developed Fischer Tropsch (FT) CANS™ technology, serving as a foundation for future joint FT+ hydrocracking projects.

For refiners, FT-Unicracking provides an excellent opportunity for repurposing existing assets to take advantage of the SAF/fossil kerosene spread. Hydroprocessing units can cost-effectively be revamped to 100% FT-Unicracking units or converted via a staged investment by first co-processing, followed by eventual 100% FT-Unicracking.

One of the key benefits of FT liquids and waxes compared to other renewable/lower carbon intensity feedstocks is that these feeds are highly paraffinic and do not contain contaminants like chlorides, sulphur, nitrogen, and high amounts of oxygenates and metals. This is a technology pathway with a high Technology Readiness Level, in combination with a high carbon efficiency and a low, zero or even carbon-negative SAF product, resulting in a high bankability score.

This short article originally appeared in the 2024 Refining India Newspaper, which you can VIEW HERE