Sustainable aviation fuel (SAF)

Sustainable aviation fuel (SAF) is a biofuel for aircraft, aimed at cutting greenhouse gas emissions compared to traditional jet fuel. Made from renewable or waste sources like used cooking oil, agricultural residues, or captured CO2, it meets strict sustainability standards to avoid food crop competition or deforestation. SAF can reduce lifecycle CO2 emissions by up to 80% (potentially 100% later) and works as a “drop-in” fuel, blending with conventional jet fuel up to 50% in existing aircraft and infrastructure. The aviation industry views SAF as key to net-zero emissions by 2050, potentially covering 65% of needed reductions.

Key Points:

• Production: Made via processes like Hydrotreated Esters and Fatty Acids, Alcohol-to-Jet, or Fischer-Tropsch, using waste oils, biomass, or synthetic CO2-hydrogen combos.
• Usage: As of 2024, SAF is just 0.53% of global jet fuel (1.9 billion liters), with production set to hit 3 billion gallons by 2030 and 35 billion by 2050. Over 450,000 flights have used SAF blends since 2008.
• Challenges:
  • Feedstocks: Limited sustainable sources risk food security or ecosystem harm. Corn ethanol-based SAF may raise emissions and food prices.
  • Cost: SAF costs 3-4 times more than jet fuel, needing policy and investment to scale.
  • Scalability: Few production facilities exist, and infrastructure needs major expansion.
• Criticism: Some call SAF’s benefits overstated, with crop-based fuels potentially increasing emissions and acting as subsidized schemes with minimal climate impact.
• Policy: Regulations like ReFuelEU (2% SAF by 2025, 70% by 2050) and U.S. tax credits push adoption, but sustainability fraud concerns linger.

Opportunities:

• SAF could create 14 million jobs globally, especially in regions growing non-food feedstocks like jatropha or camelina.
• E-fuels (from CO2 and green hydrogen) and waste-to-fuel tech could cut emissions further.
• SAF reduces non-CO2 emissions like particulates (up to 90%) and sulfur (100%), boosting air quality.

SAF’s high cost and low supply limit its impact now. Other solutions like efficient aircraft, hydrogen propulsion, and operational tweaks are also needed for decarbonization.

If “duel” meant “fuel,” this answers it. If you meant a comparison or conflict, please clarify for a focused response!