You may have come across reports about Cebu Pacific deploying Sustainable Aviation Fuel (SAF) for their latest aircraft deliveries. It’s also likely that you’ve seen articles about various airlines buying specific quantities of SAF. These actions might not seem relevant to us directly, but they carry profound implications for our environment’s well-being. Indeed, the International Air Transport Association (IATA) has set a goal of achieving net-zero carbon emissions by 2050, and the deployment of SAF is one step towards this goal. But what exactly does SAF entail, and how does it function?
Sustainable Aviation Fuel, or SAF, has been gaining attention as a greener alternative to conventional jet fuel. Derived from renewable resources such as agricultural waste, alcohol, and animal fat, SAF presents a promising solution to the environmental concerns associated with traditional aviation fuel. These sustainable feedstocks, unlike the non-renewable sources used in conventional jet fuel, allow for significant reduction in carbon emissions, offering a way forward for an industry keen on reducing its carbon footprint.
Understanding the SAF Varieties
One way to categorize SAF is into blended and unblended types. Blended SAF, as the name suggests, is a mix of traditional jet fuel and sustainable aviation fuel. The proportion of the two fuels varies, with a common blend being 70% SAF and 30% conventional jet fuel. This blend allows operators to diminish their emissions while still aligning with existing fuel infrastructure. Unblended SAF, on the other hand, is pure SAF with zero or sometimes negative carbon emissions.
Breaking Down the Processes
There are various processes involved in the production of SAF. For instance, Hydroprocessed Esters and Fatty Acids (HEFA) is a type of SAF derived from fat-based feedstocks. These feedstocks go through a chemical process known as hydroprocessing to produce hydrocarbons that are similar to conventional jet fuel.
Fischer-Tropsch (FT) SAF uses biomass, coal, or natural gas as feedstock. This process involves exposure to high temperatures and limited oxygen, producing a synthetic gas that is further processed into liquid hydrocarbons.
Alcohol-to-Jet (ATJ) is the most prevalent type of SAF. It uses alcohol, typically in the form of ethanol or butanol. The alcohol is first dehydrated, then combined with hydrogen gas to form longer hydrocarbon chains.
Lastly, Catalytic Hydrothermolysis (CH) SAF, although still experimental, is produced by reacting biomass feedstock in high-pressure environments and extreme temperatures.
Evaluating the Costs
As of mid-2023, SAF is costlier than conventional jet fuel. This price difference, along with the current high fuel costs, has made some airlines hesitant to switch to SAF. However, strategies such as taxing traditional aviation fuel or subsidizing SAF have been proposed to encourage airlines to make the transition. As SAF becomes more prevalent, its price is expected to become more competitive.
The Environmental Impact of SAF
SAF does emit carbon dioxide when burned, but at 80% less than traditional jet fuel, making it a more environmentally friendly option. Unlike conventional jet fuel, SAF’s carbon emissions occur in two stages: during the conversion of base products into SAF, and during combustion. The CO2 emissions are further offset by the absorption of carbon dioxide during the growth or production of the feedstocks, further reducing SAF’s carbon footprint.
While SAF is greener than traditional jet fuel, it has faced criticism for being a superficial solution to the significant carbon footprints of airlines. Despite this, the potential to reduce aviation’s annual CO2 emissions significantly just by switching fuel sources cannot be overlooked. It’s also important to consider that SAF might just be a temporary solution until electric aircraft technology develops enough to replace conventional combustion engine-powered aircraft.
Production
In 2023, major SAF producers include Neste in Finland, Alder Fuels in the UK, World Energy in the US, and SkyNRG in the Netherlands.
There’s no denying that the path to a greener aviation industry will be paved with numerous challenges and opportunities. However, with the increasing prominence of Sustainable Aviation Fuel, the goal seems more attainable than ever before.
First love never dies. I fell in love with airplanes and aviation when I was a kid. My dream was to become a pilot, but destiny led me to another path: to be an aviation digital media content creator and a small business owner. My passion for aviation inspires me to bring you quality content through my website and social accounts. Aviation is indeed in my blood and blog!
