Biofuels and beyond: The latest developments in sustainable air travel

Latest innovations driving the aviation industry towards a lower-carbon future

The aviation industry is facing increasing pressure to reduce its carbon footprint and adopt sustainable practices. Aviation accounts for nearly 3% of global CO2 emissions today, and without action, this figure could rise to 22% by 2050, according to the Energy Transitions Commission. To tackle this challenge, the International Air Transport Association (IATA) has committed to achieving net-zero emissions by 2050. To get there, it places great emphasis on using Sustainable Aviation Fuels, and it is pledging to counteract the remaining CO2 released into the atmosphere by aircraft through implementing measures such as ground-based CO2 capture from the air, or extracting CO2 from the exhaust gas of industrial power stations.

Existing aircraft and infrastructure have significant capital invested in them, so the aviation and aerospace industries will need to look at burning different fuels in current aircraft to achieve their net zero goal. However, it is important to note that this approach alone will not address the root cause of aviation CO2 emissions at source, so novel aircraft technologies and solutions are also necessary.

The aerospace industry is therefore actively exploring new innovations and solutions, but IATA forecasts that only 13% of the required reduction in emissions is forecast to reach net zero in 2050 will come from these. We take a look all at the latest developments in fuels and technologies below.

Exploring the viability of Sustainable Aviation Fuels

Sustainable aviation fuels (SAF) are seen as a promising solution for reducing the aviation industry's carbon footprint, as they are derived from plant oils, agricultural waste, and industrial waste. Legislation in Europe requires a minimum of 5% SAF mixed into all aviation fuels by 2030, with the potential to reduce airline CO2 emissions by about 70% by 2050. Virgin Atlantic plans to have the world's first net-zero transatlantic flight using 100% SAF in 2023, demonstrating the viability of these fuels.

However, the infrastructure for manufacturing SAF is still limited, and the costs are higher than conventional carbon-based fuels. Aviation uses massive quantities of fuel, and current capacity is insufficient to meet even 1% of global demand. Scaling up production is an economic challenge that must be addressed if SAF is to play a significant role in decarbonising aviation.

Recent research by the Royal Society concluded that there is currently no single, clear alternative to traditional jet fuel. The report examined four options for greener fuels to replace the 12.3m tonnes of jet fuel used annually in the UK, but none could replace fossil jet fuel in the short term. While some airlines use small amounts of biofuel, largely made from crops, it accounts for just 0.5% of the fuel used at London Heathrow, the world's largest user of biofuels. The Royal Society warns that producing enough biofuels to supply the UK aviation industry would require half of Britain's farming land, putting pressure on food supplies.

Advancements in jet engine technology

There's good news when it comes to jet engines! The aerospace industry is exploring innovative solutions to make flying more efficient, including greatly improved jet engine architecture and new engine designs that increase fuel efficiency and decrease flight emissions. Rolls Royce, for example, has launched a program to reduce fuel burn by 25%, and these new engines are compatible with alternative fuels like SAF and hydrogen. By the mid-2030s, these engines could be in service, paving the way for more sustainable aviation. Historically, as aircraft have become more efficient, they also become cheaper to operate, meaning that more people can fly. The resulting growth means that aviation’s emissions have continued to grow, even as aircraft have become more fuel efficient. Breaking that link may be a challenge for policymakers.

Unlocking the potential of hydrogen

When it comes to hydrogen as a fuel, it's been determined by some to be the best approach to achieve 2050 Net Zero targets. The UK's Aerospace Technology Institute's FlyZero programme, led by Hybrid Air Vehicle’s advisory board member Chris Gear, even concluded that hydrogen-fuelled aircraft could one day reach anywhere in the world in a maximum of two flights! But there are challenges to overcome, not only in aircraft design (which may look very different to today’s aircraft), but also in the infrastructure, manufacturing, delivery and storage of hydrogen fuel. Special fuel tanks in the fuselage of the aircraft must operate at very low temperatures to store liquid hydrogen. Certification requirements and development timelines mean a single aisle commercial aircraft burning hydrogen fuel won't be available until after 2035. But companies like ZeroAvia, Universal Hydrogen and Cranfield Aerospace are making progress with their aims to fit gaseous hydrogen systems and fuel cells into existing small regional turboprop aircraft. Scaling up to larger aircraft, and making the flights affordable, are some of the challenges ahead in this part of the industry.

Leading the way in sustainable air travel innovation

Airlander is at the forefront of sustainable aviation innovation. With plans for production in the near future, this aircraft offers a significant reduction in greenhouse gas emissions compared to current aircraft models, with at least a 75% reduction in emissions compared to today’s aircraft, but there are also plans in place to deliver a hybrid-electric version by 2027 with a whopping 90% reduction in emissions, and an all-electric configuration by 2030, achieving a 100% reduction in emissions. Its also the largest aircraft being designed for sustainability today – with 100 passengers, or 10 tonnes of payload, it will be the worlds most efficient large aircraft.

Airlander operates differently to other aircraft and it doesn’t replace the need for the technologies and fuels listed above. However, using the Airlander 10 to transport passengers on shorter air journeys and delivering air freight over longer ranges will make an immediate and early impact on cutting aviation emissions at the source, and provide a new, low-emissions transport option enabling new connections between ships, trains, roads and aircraft. Using Airlander on just 3% of the shortest routes in today’s passenger networks, and to replace 15% of the air freight capacity of today’s cargo aircraft, would boost the aviation industry’s efforts to remove emissions at source by around 25%.

With these innovative technologies on the horizon, we can look forward to some new options to help create a greener future for air travel.

Working together for sustainable aviation to achieve net-zero emissions by 2050

Real change in aviation sustainability requires collaboration between policymakers, regulators, and business leaders. The World Economic Forum's Clean Skies for Tomorrow program is one such initiative that brings together stakeholders from industry, government, and civil society to drive efforts towards the net-zero emissions goal by 2050.

So it is good to see that at the recent International Civil Aviation Organization (ICAO) Assembly, United Nations Member States adopted their own long-term global aspirational goal to achieve net-zero carbon emissions by 2050 for international flight operations.  his significant achievement was thanks in part to the leadership of Ms. Poppy Khoza, the first-ever female President of the ICAO Assembly. However, this needs to be done in harmony with the needs of other sectors as green energy is currently scarce, and many industries need access to these resources to decarbonize.

In conclusion, cutting-edge technology, green energy and high-density fuels are essential for achieving net zero while flying airplanes worldwide. Without changes to technology and fuel sources, aviation is on track to be responsible for 22% of CO2 emissions by 2050 according to the Energy Transitions Commission. We're facing multiple environmental challenges that will require disruption to infrastructure, technology, fuel sources, and capital investments in vehicles and airports. The good news is that as leaders in technology, we have an opportunity to change the world's view of aviation and become a model for sustainability and positive impact on climate change. But we can't do it alone; we need collaboration between policymakers, regulators, and business leaders to create new legislation, regulations, flight operations, and safety criteria for implementing new technologies. Achieving net-zero aviation will require a mature and balanced approach that takes into account the benefits of aviation while balancing its energy intensity and environmental impact. It's time to take action and work together to create a brighter, more sustainable future for aviation.

Stay tuned for more crucial developments in sustainable aviation!