Flying Green: The Rise of Sustainable Aviation Fuel (SAF)

Fossil jet fuel can be replaced with renewable Sustainable Aviation Fuel (SAF), which is made from renewable resources, to reduce emissions. Because it is a “drop-in” fuel, using it doesn’t require any changes to the infrastructure or the aircraft.

Sustainable Aviation Fuel (SAF)

What is sustainable aviation fuel? When compared to conventional jet fuel, Sustainable Aviation Fuel (SAF), an alternative jet fuel derived from renewable, non-petroleum sources such as waste oils, fats, plant-based materials, and captured carbon, is intended to drastically lower lifecycle greenhouse gas emissions.  

Without requiring engine changes, Sustainable Aviation Fuel (SAF) is a “drop-in” fuel that can be mixed with fossil jet fuel and utilized in already-existing aircraft and infrastructure.

Composition of Sustainable Aviation Fuel

What is sustainable fuel for aviation? Sustainable Aviation Fuel (SAF) is a group of fuels created from several renewable feedstocks, such as used cooking oil, agricultural waste, and even collected carbon dioxide and hydrogen. 

The mixture of isoalkanes, normal-alkanes, aromatics, and cycloalkanes found in SAFs changes according to the synthesis method. Through mixing, SAFs are designed to be compatible with current aircraft and infrastructure because of their comparable chemical and physical makeup to traditional jet fuel (kerosene).

Raw materials: bio-based, waste-based, synthetic sources

The “drop-in” fuel known as Sustainable Aviation Fuel (SAF) may be mixed with regular jet fuel and is produced from renewable raw materials such as used cooking oil, agricultural waste, and forest waste, or by producing hydrogen and carbon that has been collected. 

Depending on the feedstock and conversion process, the composition varies, but it comprises waste-based resources like animal fats and municipal solid waste, bio-based materials like vegetable oils and fats, and power-to-liquids (synthetic) sources.

Bio-based and Waste-based Sources

These fuels come from organic sources: 

• Oils and fats: The HEFA (Hydro-Processed Esters and Fatty Acids) route, a widely used process for the manufacture of SAF, frequently uses used cooking oil, animal fats, and vegetable oils as feedstocks. 
• Municipal Solid Waste (MSW): 
• Sustainable Aviation Fuel (SAF) may be made from the food and yard waste components of MSW. Crop leftovers, wood mill byproducts, and forestry trash are examples of agricultural and forestry wastes. 
• Algae: Some kinds of algae may potentially be used as a sustainable source of food. 

Synthetic sources

• These are made with collected carbon and renewable electricity: 
• PtL, or power-to-liquids:  This technology, often called e-fuels, creates liquid hydrocarbons that may be used as aviation fuel by combining hydrogen—which is made from water using renewable electricity—with carbon dioxide (CO2).

What is the composition of sustainable aviation fuel?

Although it includes hydrocarbons and is chemically comparable to conventional jet fuel, Sustainable Aviation Fuel (SAF) is made from renewable, non-fossil feedstocks such as used cooking oil, household garbage, and agricultural waste.  

SAFs can also be made synthetically by combining hydrogen and captured carbon using renewable energy, or from waste-derived materials utilizing methods like Fischer-Tropsch (FT), Alcohol-to-Jet (ATJ), or HEFA (Hydroprocessed Esters and Fatty Acids).  

It always satisfies the same exacting physical requirements as traditional jet fuel, albeit its composition can change depending on the feedstock and manufacturing process.

Difference between SAF and fossil jet fuel

When we ask, for What is the best sustainable aviation fuel? The primary distinction is the source and carbon impact: SAF is produced from a variety of sustainable sources, such as waste oils, residues, or synthetic processes driven by renewable energy, greatly reducing lifecycle greenhouse gas emissions, whereas fossil jet fuel is derived from long-buried crude oil and releases stored carbon when burned.  

Due to the identical chemical makeup of the two fuels, SAF may be mixed and utilized in current aircraft engines without requiring any changes. 

What is fossil fuel?

• Origin: Derived from subterranean crude petroleum. 
• Carbon Impact: Adding fresh CO2 to the atmosphere by releasing carbon that has been stored for millions of years. 
• Emissions: Upon burning, soot, carbon monoxide, sulfate ions, volatile organic compounds (VOCs), and CO2 are released.

Sustainable Aviation Fuel (SAF)

• Source: Biofuels made from organic resources, including used cooking oil and fats (HEFA route). 
• Wastes and residues: agricultural residues and municipal solid garbage. 
• Carbon dioxide that has been collected and zero-carbon power are used to create synthetic routes (Power to Liquid). 
• Carbon Impact: Utilizes carbon already present in the urban or natural carbon cycle to lower overall carbon emissions. 
• Emissions: Compared to fossil fuels, it can cut CO2 emissions by up to 80% during its lifetime. It can also cut emissions of sulfur and particulate matter. 
• Compatibility: Blended with regular jet fuel, it doesn’t require any changes to operate in existing aircraft engines.

Types and Best Sustainable Aviation Fuels

There are several varieties of Sustainable Aviation Fuel (SAF), rather than just one “best” one. The most advanced and widely accessible possibilities at the moment are ATJ (alcohol-to-jet) made from plant waste and HEFA (hydroprocessed esters and fatty acids) made from waste oils and animal fats.  

The feedstock utilized and the particular manufacturing method determine the efficacy and “best” option; certain techniques show notable life-cycle reductions in greenhouse gas emissions of up to 80% or more when compared to fossil jet fuel.

Important Sustainable Aviation Fuel (SAF) Types

•  HEFA, or hydroprocessed fatty acids and esters, are: Waste oils, animal fats, and certain plant oils are transformed into SAF by this procedure.  Leading manufacturers of SAF based on HEFA include Neste. 
• Alcohol-to-Jet, or ATJ: This process creates SAF by using alcohols produced from plant waste, such as maize.  With the opening of the first ATJ manufacturing facility in 2024, interest in this field is expanding. 
• Alternative Routes: Additional SAF methods include alternative Fischer-Tropsch (FT) procedures that employ distinct feedstocks and CH-SK (Catalytic Hydrothermolysis Synthesized Kerosene).

Conclusion 

By substituting fuels made from renewable resources like biomass and waste for traditional jet fuel, Sustainable Aviation Fuel (SAF) delivers substantial greenhouse gas (GHG) emission reductions of up to 80–94%, making it one of the main drivers of a greener sky.                  

SAF can be used immediately and provides a short-term option to decarbonize the aviation sector as it seeks more sophisticated technologies for longer-term net-zero targets, since it is compatible with as an interchangeable fuel for aircraft engines and current infrastructure.

Since Sustainable Aviation Fuel (SAF) can drastically cut aviation’s carbon emissions, it’s a vital tool for reaching Net Zero targets by 2050. 

You should look into SAF potential at IDCE 2025.  To accelerate SAF implementation and scale up production to meet rising demand, IDCE 2025 provides a rare opportunity to network with industry pioneers, learn about state-of-the-art production technology, and comprehend changing laws and policies.