Sustainable Aviation Fuels: Powering the Airline Industry's Net-Zero Goals
Aviation is one of the most rapidly increasing sources of greenhouse gas emissions that are driving global climate change. If global aviation as whole were a country, it would rank among the top 10 polluters of the world.
The global aviation sector is gradually changing direction to adopt a more sustainable flightpath today and one area that is showing promise is the development of sustainable aviation fuels or SAF.
What is SAF?
SAFs are liquid fuels - being used even today - in commercial aviation that reduce CO2 emissions by up to 80%.
These fuels can be produced from a number of sources including waste fats, oils and greases, municipal solid waste, agricultural and forestry residues, wet wastes, as well as non-food crops cultivated on marginal land.
They can also be produced synthetically via a process that captures carbon directly from the air. SAFs can be considered ‘sustainable’, as their feedstocks do not compete with food crops or output, nor require incremental resource usage such as water or land clearing.
The first flight using biojet fuel was undertaken by Virgin Atlantic in 2008. Subsequently, between 2011 and 2015, 22 airlines across the world performed over 2,500 commercial flights with blends of up to 50% SAF from natural feedstock.
Oslo Airport was the first airport in the world to set up a regular sustainable fuel supply for aircraft with the installation of a common hydrant system. Later that same year, United became the first airline in the world to use SAF in normal business operations.
Sustainable aviation fuel is an immediately available solution for significantly reducing the CO2 emissions of global air transportation as it can be used as a drop-in fuel without modifying existing storage and refueling infrastructure, aircraft, or engines.
Supply is trying to play catch up with demand
Globally airlines have taken to SAF like a fish to water and SAF production has tripled from 100 million litres in 2021 to over 300 million litres in 2022. Yet, this production has not been able to meet current demand.
Demand for SAF continues to grow, yet the aviation industry is challenged by limited supplies of traditional SAF feedstocks such as vegetable oils, animal fats and waste oils.
To overcome this limitation companies like Honeywell have introduced innovative ethanol-to-jet fuel processing technology that allows producers to convert corn-based, cellulosic, or sugar-based ethanol into sustainable aviation fuel.
Since 2016, over 370,000 flights have been successfully completed using SAF and it is estimated that they could contribute nearly 65% towards the net-zero-by-2050 target set by the governments and the airline industry.
However, the average number of flights are going up with each passing week and meeting future demand will require some drastic steps to be undertaken by governments and SAF manufacturers to boost production.
SAF adoption in the airline industry
Etihad was one of the pioneering airlines in the Middle East to accelerate the use of SAF on its flights. In late 2022 the company partnered with World Energy to launch its Book & Claim sustainable aviation facility for regular customers.
Speaking at the launch Mariam Alqubaisi, Head of Sustainability & Business Excellence, Etihad Airways, said: “Our NetZero flight proved Book & Claim is the only feasible path to net-zero commercial aviation using current technology and is the transition framework required until the supply of sustainable aviation fuel reaches its maturity and availability."
"Net-zero commercial aviation is possible, but we have to be honest as an industry and say there are significant logistical challenges to using SAF at present."
A month later, using the above book and claim system, Etihad Cargo facilitated DSV's SAF purchase, enabling the transport and logistics provider to offset CO2 emissions and reduce climate impact.
Masdar and Airbus
More recently, Masdar signed an agreement with Airbus to support the development and growth of the global sustainable aviation fuel market.
The agreement outlines collaboration in various areas, including Sustainable Aviation Fuels (SAF), Green Hydrogen, Direct Air Capture technologies, as well as supporting the development and implementation of book and claim solutions.
In a first for global express carriers, in February this year, DHL Express announced the launch of GoGreen Plus, a new service that will allow customers to reduce or ‘inset’ the carbon emissions associated with their shipments through the use of sustainable aviation fuel.
The new GoGreen Plus service was made possible following DHL’s recent collaborations with SAF producers like bp and Neste.
Travis Cobb, EVP Global Network Operations & Aviation, DHL Express, said: “Our greatest goal is achieving net-zero emissions by 2050.
"Using SAF is currently key to reducing carbon emissions in aviation and our GoGreen Plus service is made possible following our collaborations with bp and Neste to supply SAF to DHL Express hubs around the world.”
Meanwhile, Emirates has successfully completed ground engine testing for one of its GE90 engines on a Boeing 777-300ER using 100% Sustainable Aviation Fuel (SAF).
The ground testing and analysis demonstrated the capability of the GE90 engine to run on the specially blended 100% SAF without affecting its performance, requiring no modifications to the aircraft systems, or special maintenance procedures on the aircraft or GE90 engine to operate.
Governments playing a key role
Governments today are developing policies that are efficiently accelerating the commercial production and deployment of SAF with a number of incentives being provided on the supply side as well as the demand side.
These positive government efforts are reducing capex costs for SAF producers while incentivising airlines to use more.
The adoption of a Long Term Aspirational Goal (LTAG) by 193 member countries to achieve net-zero CO2 emissions by 2050 at the 41st International Civil Aviation Organization Assembly held last year, has further provided impetus for the transition to greener fuels in aviation.
A truly sustainable option?
Some experts argue that using SAF is a stop-gap solution for truly decarbonising the aviation industry and focussing on engine technologies to use alternate fuel systems like hydrogen or electric propulsion will provide a much better long-term solution for the industry's emissions issues.
Further, the cost of SAF today is more than twice that of conventional jet fuel. However, as its adoption becomes more widespread and production is done on a larger scale the prices are expected to come down in the near future.
“I think quantity is the main issue at the moment,” said the Director General of IATA, Willie Walsh while speaking at a recent CNBC TV interview. Currently, SAF powers less than 1% of flights globally.
Looking ahead, Walsh said airlines had ordered 14 billion liters of SAF. “I think that addresses the issue of whether airlines will buy the product.”
Overcoming initial hesitations, today more and more companies are investing in groundbreaking technologies to turn a variety of feedstocks into aviation fuel and an increasing number of airlines are buying their product.
So, whether they are quick fix or long-term sustainable solution, SAFs are here to stay while providing the most practical and economically viable option for the aviation industry to decarbonise its operations.