As the aviation industry looks to a net-zero carbon future, much of the focus is on new fuel sources and more efficient aircraft, but how can we reduce emissions of current aircraft that rely on traditional jet fuel?
One such option is Sustainable Aviation Fuel (SAF).
This series of posts will look at how it will impact the aviation industry and its goal of carbon net-zero emissions by 2050, starting with an introductory look at SAF.
What is Sustainable Aviation Fuel?
SAF is simply JET A/A-1 that is not refined from Fossil Fuels.
SAF is instead synthetically derived from renewable sources, called feedstocks, that are defined as being continually and repeatedly resourced from plant oils, sugars, municipal waste (black bag stock), forestry and agricultural residues, even algae, to name a few.
It all ends up as JET A/A-1 (kerosene).
SAF must meet stringent standards in respect of land water and energy use. I.e., avoiding deforestation or competition with food crops and having a positive socio-economic impact.
Feedstocks are processed into fuel before being blended with traditional jet fuel.
It is an essential development for several reasons.
Firstly, it creates a hugely improved carbon net carbon emissions supply chain for aviation fuel.
It achieves this by recycling the carbon emitted back to the source or repurposing hydrocarbons that would otherwise result in composting schemes or find their way into landfills.
Using SAF can reduce carbon emissions by up to 80 per cent over its lifecycle compared to traditional jet fuel.
Although not a complete reduction in carbon emissions, this is a significant difference from a relatively minor change.
How Does it Work?
SAF is an exact replacement for traditionally refined JET A1.
Any SAF that meets the ASTM D7566 synthetic fuel standard is already accepted by GE and CFM engine manufacturers and does not need additional maintenance and service requirements for the engine.
The OEM aircraft fuel system, which includes tanks, sensors, pumps, valves, vents, filters and software, must be assessed for SAF compatibility on a component-by-component basis.
OEMs are currently assessing fuel systems across all civil aircraft platforms for use with 100% SAF, but currently, SAF is mixed at a 1:1 ratio with standard jet fuel before being re-certified as Jet A or Jet A-1.
After the overall fuel system has been evaluated and certified for SAF, the Airlines can use SAF just like traditional jet fuel, meaning there is no need to adjust supply chains and aircraft.
SAF Reception and Integration
The adoption of SAF has taken off quickly; there are currently 45 airlines using it.
Airbus recently tested its A319neo to run on 100 per cent, unblended SAF.
The SAF tested consisted of waste fats, specifically paraffinic hydrocarbons, which, when evaluated, showed fewer soot particles and, by extension, greater efficiency, and reduced contrails.
So, why are there not more airlines jumping on board with SAF?
It is currently more expensive to produce than traditional jet fuel and production capacity is much lower.
However, road maps to 2050 define as much as 100% capacity for aviation SAF use.
From a financial perspective, companies like Shell and PB are working to increase production capacity, and governments are growing incentives for civil aircraft.
However, the recent COP26 summit will likely change that perspective.
Signatories made special mention of the aviation industry and their commitment to a greener and more sustainable future.
KDC Project’s involvement in SAF
Divisions of KDC Projects are involved in fuel systems design certification and testing with major suppliers across the UK that are investing in Sustainable Aviation Fuel programmes.
We are currently searching for skilled engineers with Hydrogen expertise in the aviation industry. We are working on some major ongoing projects.
Get in touch with us by emailing email@example.com or calling 01202 596 095.