Streamlining the development of sustainable aircraft fuels
An EU-funded consortium is developing novel screening, modelling and optimisation processes for alternative jet fuels, supporting efforts to create a cleaner and more sustainable European aviation industry.
© chalabala #182163972, source: fotolia.com, 2018
The EU has set ambitious targets for at least 40 % of aircraft to be powered by low-carbon sustainable fuels by 2050 as part of broader emissions reduction efforts across the transport sector. To achieve this goal, novel fuels need to be developed, derived from renewable non-fossil sources while meeting stringent aviation safety and performance requirements.
To help establish a sustainable alternative jet fuel (SAJF) industry in Europe, the EU-funded JETSCREEN consortium is developing tools and methods to screen and assess alternative fuels using small-scale, low-cost experimental testing and advanced computer-modelling techniques. The goal is to reduce the substantial investment needed to seek approval for a new alternative fuel under the ASTM D4054 international standardisation process, a rigorous procedure that complies with the aviation industrys very high safety requirements.
Currently, not a single EU company is continuously producing sustainable alternative jet fuels. Most SAJF production pathways stem from US-based funding, research labs and companies, says JETSCREEN coordinator Bastian Rauch of DLR in Germany. Fuel impacts a wide range of aircraft components and system properties, sometimes in conflicting ways. A fuel composition that has a positive effect on the fuel system might have a negative impact on emissions, for example. New fuels therefore have to be thoroughly tested: its a very interdisciplinary, time-consuming and costly process.
Optimising promising fuels
The JETSCREEN consortium, which includes leading research institutes, major aerospace and engineering firms and innovative SMEs, is addressing that challenge.
The partners are developing small-scale experimental processes for a variety of alternative fuel candidates, such as fuels derived from organic oils and sugars, with different compositions and properties. These latest generations of bio-derived fuels are more sustainable than previous versions as they are derived from sources that do not compete with food supplies and are not major consumers of prime agricultural land or fresh water.
The JETSCREEN experiments are used to understand the effects of the different properties of alternative fuels, with the data captured in standardised formats and stored in a database with other information from scientific literature and prior studies. These data, in turn, help scientists understand the basic physical phenomena of the fuel composition, thereby underpinning the development of predictive modelling tools to screen and assess a specific fuels impact on the performance of the fuel system, combustion and emissions.
Moreover, once the sequence of models exists to derive a relationship between fuel composition and system performance, then this process can be reversed to optimise the fuel and test different formulations for features such as targeted performance or emission reductions, Rauch explains.
Faster approvals, reduced risk
The ultimate aim of the JETSCREEN project is to use the tools and methods to provide candidate fuels with a certificate of analysis containing key data that can assist the approval process. This would reduce the risks for fuel producers and investors in deciding to launch an application for approval of a new fuel type or blend, supporting innovation in the jet fuel sector, which is dominated by large oil- and technology-licensing companies that can afford the high costs involved.
The JETSCREEN approach is also set to contribute to the future design of fuel-flexible components for aircraft. It will lay the foundations for further research into methods that would optimise fuel and aircraft systems to achieve even greater reductions in emissions, as well as improvements in fuel performance and sustainability.
We believe investment risks can be lowered by providing these tools, Rauch says. Furthermore, small innovative start-ups can receive much-needed early feedback on performance to help develop their products and obtain funding.