sustainable aviation is one of the flagship products of the new economy. He seeks to reduce the carbon footprint of this transportation system, both through his innovative design efforts, such as his V-shaped plane, featured in a previous article, and through the use of alternative fuels. However, electric or hydrogen fuel cell systems are still in development and won’t be flying anytime soon. For the time being, the industry is turning to fuels based on industrial oils, but the costs are still high and they are typically used to produce diesel rather than kerosene. Organic waste, on the other hand, is used to obtain methane, which is not used for aviation applications today. Fortunately, researchers at the US National Renewable Energy Laboratory seem to have found a solution.
Journey from landfill to fuel tank
Today, much of the high-moisture organic waste ends up in landfills or, at best, is used to produce methane. However, new technology presented in the scientific publication PNAS makes it possible to convert this kind of waste, whether of animal or vegetable origin, into sustainable kerosene. The secret is to interrupt the methanation process and obtain volatile fatty acids (known as VFAs). Two catalytic processes are then applied to produce a fuel suitable for aviation. In the last step add 30% conventional kerosene to the mixture.
Researchers say the new strategy has several advantages. On the one hand, greenhouse gas emissions are reduced by 165%. This figure is the result of combined reductions in aircraft emissions and landfill emissions. In addition, the soot produced by combustion is reduced by 34%. This residue doubles the heat build-up by CO2.
After demonstrating the feasibility of the process in the lab and passing industry certification processes, the team plans to conduct first tests on real aircraft with US airline Southwest Airlines in 2023.
Green hydrogen: the future of aviation
Derek Vardy, the engineer who led the study, points to the strategy as an essential milestone for sustainable aviation. However, it is only a transitional period. True sustainability comes from using fully renewable energy sources. In that sense green hydrogenProduced by an electrolysis process powered by renewable energy, the can be one of the great assets of future aviation. That’s Airbus’ vision, presenting three prototypes powered by liquid hydrogen for the ZeroE project. The largest models reach ranges of over 2,000 nautical miles. In addition to working with modified gas turbines, hydrogen produces electricity and enables hybrid propulsion systems.
According to Glenn Llewellyn, Airbus VP of zero-emission aircraft, the high energy-per-unit-mass requirements of large passenger aircraft make it impossible to use 100% electric propulsion. In other words, the weight and bulk of the critical battery system prevents the plane from flying efficiently. That is why today green hydrogen seems like the most realistic road to sustainable aviation.
sauce: BBC, Airbus
