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# Carbon Neutral Fuels Unveils FlexSAF, Raising Project Starling’s Output 70% to 42,000 Tonnes a Year
- URL: https://review.iffw.sg/carbon-neutral-fuels-unveils-flexsaf-raising-project-starlings-output-70-to-42-000-tonnes-a-year/
- Published: 2026-10-19T00:30:00.000Z
- Updated: 2026-10-19T00:30:00.000Z
- Description: Carbon Neutral Fuels unveiled FlexSAF, a design producing both eSAF and advanced bioSAF on one Fischer-Tropsch line at Project Starling in West Cumbria, raising output 70% to about 42,000 tonnes a year. A planning application is due in 2028, with first fuel in Q4 2031.
- Author: Editor
- Tags: News, Aviation

Carbon Neutral Fuels (CNF) has unveiled "FlexSAF," a plant design that produces both eSAF and advanced bioSAF at a single facility, debuting at its Project Starling site in Workington, West Cumbria. The redesign raises the project's target output by 70%, from 25,000 to about 42,000 tonnes of SAF a year, which CNF says reduces production cost per tonne.

### How the Design Works 

FlexSAF combines two feedstock pathways: eSAF made from biogenic CO2, water and renewable electricity, and advanced bioSAF made from biomethane. Both routes feed into a single shared Fischer-Tropsch synthesis and upgrading line, so the project gets two pathways without building two separate plants. CNF says the shared infrastructure is expected to lower the cost per tonne of fuel and lets the plant adjust its production mix, within the limits of the equipment, in response to feedstock availability and market demand.

### Where the Extra Output Comes From 

Process optimisation work accounts for the increase. By recycling the naphtha and tail gas by-products back into the syngas stream, virtually all output is converted directly into aviation-grade jet fuel. CNF expects the commercial-scale hybrid design to be a UK first.

### The Supply Argument 

CNF positions the design against a concern that statutory UK and EU SAF mandates are rising faster than dedicated production capacity can be built. It notes the UK imports more than 70% of its aviation fuel, and says the project will turn an underused 40-acre brownfield site into a domestic energy asset, creating more than 500 construction jobs and more than 150 skilled operational roles.

### Timeline 

Engineering is under way with io consulting. CNF signed a Planning Performance Agreement with Cumberland Council in June 2026 and is holding a public drop-in session for the local community on 15 October 2026\. A full planning application is due in Spring 2028, with first fuel targeted for Q4 2031.

### What Remains Undisclosed

The release gives no financing arrangements, offtake agreements or capital cost, and no cost-per-tonne figures. It also does not name the sources of biogenic CO2, biomethane or renewable electricity, or say how the 42,000 tonnes would split between eSAF and bioSAF.

*Source:* [*Carbon Neutral Fuels*](https://www.carbonneutralfuels.com/news/flex-saf-redesign-at-starling?ref=review.iffw.sg)*, 13 October 2026.*