Renewable Aviation Fuel: A Sustainable Path for Aviation
Aviation is a cornerstone of global transportation, connecting people and goods across continents. However, it is also a significant contributor to greenhouse gas emissions, with commercial aircraft responsible for approximately 2–3% of global CO₂ emissions. In response to the growing environmental concerns, the aviation industry is increasingly exploring Renewable Aviation Fuel (RAF) as a sustainable alternative to conventional jet fuel.
What is Renewable Aviation Fuel?
Renewable Aviation Fuel, often referred to as sustainable aviation fuel (SAF), is produced from renewable resources rather than fossil fuels. These resources include plant oils, agricultural residues, algae, and even certain types of municipal waste. Unlike conventional jet fuel, RAF is designed to reduce carbon emissions across its lifecycle—from production to combustion in aircraft engines. The primary aim is to create a fuel that is chemically similar to traditional jet fuel, enabling it to be used in existing aircraft engines and infrastructure without modifications.
Types of Renewable Aviation Fuel
There are several pathways for producing RAF, each with distinct feedstocks and processing methods:
Hydroprocessed Esters and Fatty Acids (HEFA):
This is currently the most widely used method. Oils from plants, such as camelina, jatropha, or used cooking oil, are processed with hydrogen to produce a high-quality jet fuel. HEFA fuels can typically be blended with conventional jet fuel up to 50% without requiring engine modifications.
Fischer-Tropsch Synthetic Paraffinic Kerosene (FT-SPK):
Biomass such as wood chips, agricultural residues, or municipal solid waste can be converted into synthetic fuel through a chemical process called the Fischer-Tropsch method. FT-SPK fuels offer excellent energy density and combustion properties.
Alcohol-to-Jet (ATJ):
In this process, alcohols like ethanol or butanol are chemically converted into jet fuel. ATJ fuels are gaining attention due to the availability of bioethanol from crops like sugarcane or corn.
Power-to-Liquid (PtL) or Electrofuels:
This cutting-edge approach uses renewable electricity to produce hydrogen, which is then combined with captured CO₂ to create synthetic jet fuel. This method has the potential to achieve near-zero net carbon emissions.
