The Aviation Industry Journey to Sustainability – Beyond SAF Sustainable Aviation Fuels

What is Sustainable Aviation Fuel (SAF)?

Sustainable Aviation Fuel, or SAF, is a renewable and environmentally friendly alternative to conventional jet fuel. It is derived from sustainable feedstocks such as agricultural residues, waste oils, and dedicated energy crops.

Airlines belonging to the International Air Transport Association (IATA) have made a commitment to reach carbon neutrality in their operational activities by 2050. They have identified Sustainable Aviation Fuel (SAF) as a viable solution that could potentially reduce their emissions by up to 65%.

SAF has the potential to achieve this because it belongs to the category of biofuels, which are derived from plant or animal materials instead of fossil fuels. BP produces SAF by utilizing cooking oil and animal waste fat as raw materials. Additionally, alternative options for SAF production include utilizing agricultural and forestry waste, as well as municipal waste.

Types of Sustainable Aviation Fuels (SAF)

There are several types of Sustainable Aviation Fuels (SAF) available, each with its own production process and properties. Some of the most common types of SAF include:

1. Hydroprocessed Esters and Fatty Acids (HEFA)

This type of SAF is produced from vegetable oils, animal fats, and used cooking oil through a process called hydroprocessing. HEFA SAF is the most commonly produced and used SAF today.

2. Fischer-Tropsch (FT)

FT SAF is produced from biomass or natural gas using a process called gas-to-liquid conversion. FT SAF has high energy density and is considered a drop-in fuel that can be used in existing engines without modification.

3. Alcohol-to-Jet (ATJ)

ATJ SAF is produced from sugar, corn, or other feedstocks through fermentation and conversion to alcohol, which is then processed into sustainable jet fuel.

4. Pyrolysis

Pyrolysis SAF is produced from the thermal decomposition of biomass. The process breaks down the feedstock into a gas that is then converted into liquid fuel.

5. Biomass-to-Liquid (BTL)

BTL SAF is produced from a variety of feedstocks, such as wood chips, agricultural waste, and straw, through gasification and conversion to liquid fuel.

How is SAF Currently Produced?

Traditional jet fuel is made from carbon-rich crude oil that is extracted from the ground. When it is burned in aircraft engines, that carbon is released into the atmosphere. Sustainable aviation fuel, however, is made from animal byproducts or agricultural waste, oils from plants and other biomass. When SAF is made from mustard seeds, for example, new mustard plants absorb and store the carbon molecules released in its combustion, making it renewable.

SAF can be manufactured using renewable feedstocks that are not derived from petroleum sources. These feedstocks include, but are not limited to, the organic waste from municipal solid waste, woody biomass, fats, greases, oils, and other similar materials. The production of SAF is still in its early stages, but there are currently three known commercial producers:

1. World Energy initiated SAF production in 2016 at its facility in Paramount, California. Initially, they supplied fuel to Los Angeles International Airport and later expanded their supply to other airports in California.
2. Neste, an international producer, began supplying SAF to San Francisco International Airport in 2020. They subsequently expanded their supply to other airports in California in 2021 and 2022. Additionally, they started supplying SAF to Aspen/Pitkin County Airport and Telluride Regional Airport, both located in Colorado.
3. Montana Renewables LLC partnered with Shell to commence SAF production in 2023. They utilize an existing petroleum production plant and supply fuel to several partner airlines.

The production of approved fuels for aviation purposes, as outlined by the ASTM (American Society for Testing and Materials), involves various technology pathways and blending limitations. The ASTM D7566 Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons sets forth quality standards for non-petroleum-based jet fuel. It specifies the approved SAF-based fuels and the maximum allowable percentage of these fuels in a blend with Jet A fuel. All three existing plants utilize the hydro processed esters and fatty acids pathway, as indicated in the table on this page. Furthermore, it is anticipated that new domestic plants will emerge, employing the alcohol-to-jet pathway with ethanol as a feedstock.

The ASTM D1655 Standard Specification for Aviation Turbine Fuels permits the co-processing of biomass feedstocks at petroleum refineries, allowing blends of up to 5%. This standard governs the quality specifications for conventional petroleum-based aviation turbine fuels.

How Sustainable Aviation Fuel Works ?

SAF works in a similar way to traditional jet fuel, powering aircraft engines and enabling them to generate thrust. The key difference lies in the reduced greenhouse gas emissions associated with SAF. When SAF is burned, it releases significantly fewer carbon dioxide (CO2) emissions compared to conventional jet fuel. This reduction in emissions plays a crucial role in mitigating the impact of aviation on climate change.

How is SAF Different From Traditional Jet Fuel?

SAF stands apart from traditional jet fuel due to its renewable nature and lower carbon footprint. While conventional jet fuel is derived from fossil fuels, SAF is produced from sustainable feedstocks. Additionally, SAF has the potential to reduce greenhouse gas emissions by up to 80% compared to traditional jet fuel. This significant reduction makes SAF a vital component in the aviation industry’s efforts to achieve carbon neutrality.

Sustainable Aviation Fuel Benefits

SAF offers a range of benefits that make it an attractive option for the aviation industry:

Environmental Impact: The use of SAF can help reduce aviation’s carbon footprint, contributing to global efforts to combat climate change.

Energy Security: By diversifying fuel sources, SAF reduces dependence on fossil fuels, enhancing energy security.

Air Quality Improvement: SAF produces fewer emissions of pollutants like sulfur and particulate matter, leading to cleaner air around airports and communities.

Technological Compatibility: SAF can be used in existing aircraft engines without requiring any modifications, making it a viable option for the current aviation fleet.

Job Creation: The development and production of SAF create new opportunities for job growth in the renewable energy sector.

Why Should We Switch To Sustainable Aviation Fuel “SAF”?

The aviation industry plays a significant role in global carbon emissions, and the adoption of SAF is a crucial step towards achieving sustainability. By switching to SAF, we can:

• Reduce greenhouse gas emissions: SAF has the potential to significantly reduce CO2 emissions, helping mitigate the impact of aviation on climate change.
• Enhance environmental stewardship: The use of SAF demonstrates a commitment to preserving the environment and reducing the ecological footprint of the industry.
• Drive innovation: Investing in SAF encourages research and development of new technologies, creating a pathway for cleaner and more sustainable aviation practices.
• Meet regulatory requirements: As governments and international organizations set stricter emission standards, adopting SAF becomes essential for compliance.

Frequently Asked Questions

How much can SAF reduce greenhouse gas emissions?

SAF has the potential to reduce greenhouse gas emissions by up to 80% compared to traditional jet fuel. This significant reduction in emissions plays a vital role in mitigating the impact of aviation on climate change.

Are there any drawbacks to using SAF?

While SAF offers numerous benefits, there are some challenges to its widespread adoption. One of the primary concerns is the limited availability and high production costs, which can make SAF more expensive than traditional jet fuel. Additionally, the infrastructure required for the production and distribution of SAF needs further development to support its widespread use.

How does SAF impact airplane performance?

From a performance perspective, SAF has been proven to be compatible with existing aircraft engines without requiring any modifications. This means that airplanes can operate smoothly and efficiently using SAF, ensuring no compromise in performance or safety.

How much SAF is currently used in commercial aviation?

Currently, the use of SAF in commercial aviation is relatively limited. However, there is a growing interest and commitment from airlines and governments to increase its usage. Several airlines have already started incorporating SAF into their fuel blends, and initiatives are underway to expand its availability in the market.

What are the future prospects for SAF adoption in aviation?

The future prospects for SAF adoption in aviation are promising. The International Air Transport Association (IATA) has set ambitious goals to achieve carbon-neutral growth in the industry by 2050. To achieve this, the widespread use of SAF will be crucial. Governments, industry stakeholders, and research organizations are actively working together to develop sustainable feedstocks, improve production processes, and create a supportive regulatory framework to accelerate the adoption of SAF.

What are the expected costs of SAF compared to traditional jet fuel in the future?

Currently, SAF production costs are higher than traditional jet fuel due to factors such as limited production capacity and feedstock availability. However, as technology advances and production scales up, it is expected that the costs of SAF will decrease, making it more competitive with traditional jet fuel in the future. Additionally, government incentives and market demand can further drive down the costs of SAF.

How can government policies and regulations encourage the use of SAF?

Government policies and regulations play a vital role in encouraging the use of SAF. Some strategies include:

• Implementing incentives and subsidies to reduce the cost of SAF production and increase its availability in the market.
• Setting carbon pricing mechanisms that create economic incentives for airlines to switch to SAF.
• Establishing long-term targets and commitments for reducing greenhouse gas emissions in the aviation sector.
• Supporting research and development efforts to improve SAF production processes and develop advanced technologies.
• Collaborating with international organizations and other governments to create harmonized regulations and standards for SAF.

By implementing these measures, governments can create an enabling environment for the widespread adoption of SAF and accelerate the transition to a more sustainable aviation industry.