[C Tech Now] SAF's "Turtle Pace," "Increase Production by 1000 Times"

Highest Carbon Emissions from Aircraft Transport
IATA, 21.2GT Reduction with Sustainable Aviation Fuel
EU Mandates 70% Sustainable Aviation Fuel
Limitations in Raw Material Supply Using Waste Cooking Oil
Insufficient Technology for Using Agricultural and Forestry Byproducts
Facility Costs and High Prices Also Obstacles
Need for New Production Methods Through Technology Investment

Korean Air conducted the first domestic demonstration flight using Sustainable Aviation Fuel (SAF) in September 2023. This demonstration flight utilized SAF supplied by GS Caltex from Neste in Finland. The photo shows an official holding the SAF used during the demonstration flight. Photo by Korean Air

Fulcrum BioEnergy has attracted about $1 billion (approximately 1.38 trillion KRW) in investment for its technology that produces eco-friendly aviation fuel from household waste. Major global oil companies and airlines such as BP, United Airlines, Cathay Pacific Airways, and Japan Airlines have funded this company. Domestically, SK Innovation also invested 26 billion KRW, promoting that it secured waste resource recycling technology. However, the company laid off about 100 employees in May and has effectively ceased operations.

Founded in 2007, the company announced an ambitious plan to extract gas from shredded landfill waste and then liquefy it into aviation fuel but faced difficulties in mass production. Bloomberg cited insiders saying, "Fulcrum, which raised $1 billion, is on the brink of collapse," calling it "one example of setbacks in the aviation industry's efforts to secure clean fuel." SK Innovation wrote off its entire investment in Fulcrum in April.

Aircraft emit the most carbon dioxide among transportation modes. According to the UK Department for Business, Energy & Industrial Strategy, a short-haul flight emits 255g of carbon per passenger per kilometer, significantly more than buses (105g) and diesel mid-sized cars (171g). The aviation industry is estimated to account for 2-3% of global carbon emissions. According to the International Air Transport Association (IATA), in 2019, the aviation industry's carbon emissions were 1.02 GT (gigatons), representing about 2.8% of global carbon emissions and 13.4% of transportation sector emissions.

SAF Contributes 65% to Aviation Industry Carbon Neutrality

To achieve carbon neutrality by 2050, it is inevitable to reduce carbon emissions from aircraft. Related international organizations have been announcing regulations consecutively. The International Civil Aviation Organization (ICAO), under the United Nations (UN), has implemented the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) since 2021 to achieve carbon neutrality in the aviation sector. CORSIA requires airlines that exceed carbon emission limits to purchase emission allowances in the carbon market to offset their emissions. After a voluntary participation period from 2021 to 2026, it will become mandatory from 2027.

As of January 2024, 126 countries worldwide, including South Korea, participate in CORSIA. IATA also adopted a resolution at its 77th General Assembly in 2021, declaring carbon neutrality for the aviation industry by reducing 21.2 GT of carbon emissions from 2020 to 2050.

However, reducing carbon emissions in the aviation sector is a very challenging task. Internal combustion engine vehicles on land, such as passenger cars and trucks, are utilizing electric vehicles powered by batteries or hydrogen fuel cells. Shipbuilding is developing propulsion vessels using hydrogen or ammonia. However, electrification of aircraft is difficult due to heavy batteries. To achieve efficiency comparable to conventional jet fuel, an energy density of 1000 Wh/kg by weight is required. Currently, lithium-ion batteries have an energy density of about 250 Wh/kg. Hydrogen fuel cells require about four times the volume compared to conventional jet fuel.

The most realistic method to reduce carbon in the aviation industry emerging is Sustainable Aviation Fuel (SAF). SAF is produced using waste resources such as used cooking oil, sugarcane, biomass, and seaweed. Using SAF can reduce carbon emissions by up to 80% compared to conventional aviation fuel. Notably, it can be blended with conventional jet fuel up to 50% and can be applied to all existing aircraft, which is an advantage. IATA forecasts that SAF will contribute about 65% to achieving carbon neutrality in the aviation sector by 2050.

EU to Mandate 70% SAF Use by 2050

Internationally, there is a trend to mandate SAF usage. The European Union (EU) reached a final agreement on the ‘REFuel EU Aviation Law’ last April. According to this law, from 2025, airports across 27 countries must blend at least 2% SAF when refueling aircraft. The mandatory blending ratio will gradually increase to 6% by 2030, 20% by 2035, and 70% by 2050. France has enforced a mandate since 2022 requiring at least 1% SAF blending for flights departing from the country.

The United States announced the ‘2022 September SAF Grand Challenge Roadmap’ with the goal of replacing 10% of fuel for domestic and international flights with SAF by 2030 and 100% by 2050. To support this, the US offers tax credits of $1.25 to $1.75 per gallon for SAF produced and sold domestically through the Inflation Reduction Act (IRA). Japan announced a policy to mandate that 10% of fuel consumption by Japanese airlines be replaced with SAF by 2030.

Currently, SAF technology remains in its early stages. Production volume is low, and prices are very high, presenting many challenges ahead. At the annual meeting held in Dubai in June, IATA presented a total SAF demand of 51 million tons by 2030, significantly down from the 63 million tons announced in December last year.

The aviation industry is concerned that current technology and production levels will not supply sufficient SAF to meet demand. IATA expects SAF production to triple to 1.5 million tons this year compared to last year. However, this accounts for only 0.53% of total aviation fuel demand. IATA stated that production must increase by 1000 times by 2050.

◇ HEFA Leading Commercialization, but Raw Material Supply Limited = SAF must meet stringent quality standards because it is blended drop-in with conventional jet fuel. The most widely accepted SAF quality standards are ASTM D7566 and D1655 by the American Society for Testing and Materials (ASTM). Currently, 11 technologies across 9 processes have received ASTM approval, with additional technologies under evaluation. The four technologies attracting industry attention are Hydroprocessed Esters and Fatty Acids (HEFA), Alcohol to Jet (ATJ), Gasification (FT), and Power to Liquid (PTL).

The most commercially advanced is HEFA (Hydroprocessed Esters and Fatty Acids). This technology converts waste cooking oil, fats, and other animal and vegetable oils into fuel through hydrogen processing. It can utilize existing refinery infrastructure and is more economical compared to other methods. However, its drawbacks include limited raw material supply and the need for hydrogen. Despite being closest to commercialization, it is expected to produce only about 5% of total aviation fuel demand due to difficulty in securing sufficient waste cooking oil.

ATJ (Alcohol to Jet) ferments agricultural byproducts, forestry residues, and municipal waste to produce alcohol, which is then converted into hydrocarbons. It can utilize a wider variety of raw materials than HEFA but is still underdeveloped technologically. Corn and sugarcane can be used as feedstocks, but competition with food resources is an issue.

Gasification, like ATJ, uses residues and waste. It heats and decomposes raw materials to generate synthesis gas (a mixture of carbon monoxide and hydrogen), which is then converted into hydrocarbons through the Fischer-Tropsch process. While raw material costs are low, the process is complex and equipment costs are high.

PTL (Power to Liquid), also known as e-Fuel, synthesizes hydrocarbons from green hydrogen and carbon dioxide. Green hydrogen is produced using renewable energy sources such as solar and wind power, and carbon dioxide is captured, making it the most environmentally friendly. PTL is in the early stages of development and is more expensive than other processes. Fuel produced using PTL costs about eight times more than conventional fossil fuels.

To sufficiently supply the SAF needed in the aviation sector, investment in technologies other than HEFA must be expanded. IATA emphasized, "HEFA will account for 80% of SAF in the next five years," and urged accelerating SAF production by utilizing other certified technologies such as agricultural and forestry residues and municipal waste.