Neste has developed the proprietary NEXBTL technology for the production of renewable fuels. Renewable diesel is a hydrodeoxygenated paraffinic fuel, which can be used in conventional diesel engines without engine modifications. Neste's sustainable aviation fuel is a drop-in fuel, which can be mixed with kerosene to produce a mixture that contains at least 50% kerosene. Among others, it is used by Lufthansa and the Swedish Air BP. In 2019, Neste produced about 100,000 tonnes of sustainable aviation fuel and plans to produce around 1.5 million tonnes per year by 2023.