Aviation is one of the least sustainable and hard to decarbonise activities. It accounts for 2.5% of global CO₂ emissions and has contributed around 4% to global warming to date. Sustainable Airline Fuel (SAF) can reduce emissions upto 80% but will it help decarbonise the aviation industry now?
With the announcement that Power2X and Advario are developing a world-scale production and storage hub in the Port of Rotterdam, SAF developments get a new boost. The Power2X production facility for sustainable aviation fuel (e-SAF) and synthetic, ultra-low carbon fuels in the Port of Rotterdam will have the capacity to produce over 250,000 tonnes/year. It will therefore be the largest e-SAF facility announced to date.
This follows the news from last month, where VARO Energy has unveiled plans to construct a substantial SAF manufacturing facility at the Gunvor Energy Rotterdam site. This facility, wholly owned by VARO, will feature a pretreatment unit, ensuring flexibility in utilizing renewable feedstock and optimizing production capabilities. The facility’s overall SAF production capacity will be 245,000 tonnes/year.
What is SAF?
SAF is the main term used by the aviation industry to describe a non- conventional (fossil derived) aviation fuel. SAF consists of three main elements:
1. Sustainability: in this context sustainability is defined as something that can be continually and repeatedly resourced in a manner consistent with economic, social and environmental aims, and conserves an ecological balance by avoiding depletion of natural resources.
2. Feedstock: It is a fuel for aviation with an alternative feedstock (raw material from which fuels are produced) to crude oil. Feedstocks for SAF are varied; ranging from cooking oil, plant oils, municipal waste, waste gases, and agricultural residues – to name a few
3. Fuel: This means jet fuel that meets the technical and certification requirements for use in commercial aircraft. The chemical and physical characteristics are almost identical to those of conventional jet fuel and it can be safely mixed with the latter to varying degrees, use the same supply infrastructure and do not require the adaptation of aircraft or engines.
The use of SAF has been shown to provide significant reductions in overall CO2 lifecycle emissions compared to fossil fuels, up to 80% in some cases. Furthermore, SAF contains fewer impurities (such as sulphur), which enables an even greater reduction in sulphur dioxide and particulate matter emissions than present technology has achieved. But can SAF Decarbonise aviation now?
Life-cycle carbon saving
SAFs come in two main varieties based on sourcing: Liquid biofuels are made from algae, food crops and food waste (including used vegetable oils and even sewage), while synthetic fuels include green hydrogen or synthetic kerosene. Both biofuels and synthetic fuels could be key routes to cutting the aviation industry’s heavy climate footprint, though big challenges loom.
A major challenge SAFs face is that, like fossil fuels, they still must be burned for a plane to fly, so they release carbon dioxide when ignited. As a result, maximizing benefits depends on cutting carbon emissions along the entire SAF supply chain and throughout their entire life cycle (so called life-cycle carbon saving). For example, crop-based biofuels have an advantage over traditional fuels because they absorb atmospheric carbon as they grow, advocates say.
However, not all SAFs offer equivalent lower life-cycle carbon benefits, and many pose other environmental threats. Earlier this year, the Royal Society, the U.K.’s national academy of sciences, published a report assessing a variety of alternative fuels, including biofuels, and found that availability and accessibility are key problems, among a litany of others. “What we saw is that there’s a huge range of uncertainty in terms of the environmental impact of these fuels,” said Marcelle McManus, an author of the report and professor of energy and environmental engineering at the U.K.’s University of Bath.
Another “quite stark” finding, she explains: Some proposed fuels don’t meet the carbon-reduction targets set by some governments, such as the EU and the U.S., the latter of which is aiming for 50% life-cycle reductions from fuels. As things stand only a “very few” fit the bill, according to McManus: “Biofuels made from oil crops, with their current processes, don’t meet the targets,” she notes.
Can SAF decarbonise aviation now?
Experts largely agree that if SAFs are produced sustainably. using appropriate feedstocks, then they can help reduce aviation’s heavy emissions burden. But to do so, 449 billion liters would need to be produced every year, according to the IATA. That’s a far cry from the hundreds of thousands made annually now.
An earlier review by the University of Florence found that the need for the massive scale-up of production, investment and guaranteed availability of a variety of SAF feedstocks — particularly those waste streams already in use by other industries — remain challenges to growth; sticking points on which other experts agree. An interim goal of 10% of aviation fuel from SAFs by 2030 has been set by the industry and national governments, but would already require construction of some 300 production plants globally.
No matter SAF progress over the next few years, analysts agree that pegging the aviation sector’s sustainable hopes and carbon cuts entirely on SAFs is impractical. Other solutions are necessary, particularly in the short term, to drive down aviation’s emissions.
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This post is based on a publication by Mongabay
