In the era of climate change, global aviation executives are looking at blue skies. While the industry is only responsible for a small percentage of global emissions, it has a high profile, in part because of its discretionary nature. Low-emission flight propulsion technologies that use hydrogen or electric batteries stay away for decades. Meantime, sustainable aviation fuels (SAFs) can bridge the gap by reducing the use of petroleum jet fuel.
Made from agricultural or recycled fatty products, SAFs do release carbon, but much less on their respective life cycles than fossil fuels. Government subsidies encouraged its use in production and mixing mandates. Under current legislation, commercial radiators can run on mixtures of up to half with conventional fossil fuels. This means that the EU-wide 2030 target of 5 percent of the total fuel used, of less than 1 percent currently, has no ambition.
This did not discourage energy market participants such as Shell and Finnish refiner Neste Oyj. Shell will produce more than 800 000 tonnes of renewable fuel at a new Rotterdam facility that will come into operation in 2024. Half of the output will probably go to the manufacture of SAF. It covers approximately EU demand. The plant will use the hydro-processed esters and fatty acids (HEFA) process, the only commercially viable technique used. It converts materials such as recycled cooking fats into jet fuel, which reduces emissions by about 80 percent.
Using the same process, Neste aims to produce about 1.5 million tonnes of SAF by 2025, if EU targets of 2 percent of SAF use are accepted by that year, says Neste. The refiner already earns most of its operating profit from renewable fuels.
Cost remains the biggest obstacle. Currently, HEFA processes cost three to five times more than kerosene. In addition, scale is limited by the availability of raw materials. Other liquid fuel technologies that use gasification and or convert alcohol to jet fuel may become commercially viable by the end of this decade. For now, Shell and Neste are on the right track by focusing on SAFs.