Current commercial use of renewable jet fuel
In the past near ten years, as several production pathways were approved and added to the standard specification ASTM D7566 (see Section 3), there has been a considerable number of projects and initiatives by numerous airlines to
Figure 3.9 Solar tower concentration facility for field validation of the solar-thermochemical fuel production process as part of the EU-funded collaborative project SUN-to-LIQUID. The facility is located at IMDEA Energy Institute, Mostoles, Spain.
Source: Picture courtesy of E. Koepf/© ETH Zürich 2017.
use renewable jet fuels in commercial flights. A pioneering example was the project burnFAIR. in Germany, where Lufthansa operated 1188 regular commercial flights between Hamburg and Frankfurt over a period of six months in 2011. In that project, one engine of a single Airbus A321 was fuelled with a 50% blend of HEFA-SPK (Zschocke, 2014). This was the first time that an airline used renewable jet fuel in a series of scheduled commercial flights. Many projects by other airlines followed. Information about current activities and flights powered by renewable jet fuel is provided by the ICAO Global Framework for Aviation Alternative Fuels (GFAAF) (ICAO, 2018).
In all of the early demonstration projects, the used renewable fuel was supplied from dedicated storage systems to the aircraft; it was not delivered through the common fuel hydrant systems at airports. Thereby it was ensured that the renewable jet fuel could be supplied to the specific aircraft (or even specific engine) of the airline that had purchased the renewable fuel batch. However, such a procedure is impracticable for day-to-day business, considering a future large-scale deployment of renewable jet fuel. Consequently, recent
Renewable fuels for aviation 33 developments have been focused on introducing renewable jet fuel into the common fuel hydrant systems of selected airports.
Oslo Airport was the first example, where kerosene produced from biomass was distributed through the hydrant system, thereby supplying all aircraft departing from Oslo with small quantities of renewable jet fuel (Larsen, 2017; McKenna, 2017). Other airports followed, such as Los Angeles and Toronto (GreenAir, 2018a), or announced to do so (Port of Seattle, 2018; SkyNRG, 2018).
Nevertheless, despite these encouraging developments, the current share of renewable jet fuel in the total volume of jet fuel consumed worldwide (about 270 Mt per year (IATA, 2017)) is negligibly small. This is mainly a consequence of unfavourably high cost of production of renewable jet fuel, as will be discussed in more detail in the next section.
It is also interesting to note that in almost all demonstration projects, HEFA fuel (see Section 4.1) was used. Only in a very few cases were other fuel options applied, e.g. synthetic isoparaffinic (SIP) jet fuel produced by Amyris on a few national Air France flights in France in 2014 (GreenAir, 2014a) and AtJ fuel produced by Gevo on singular flights by several airlines in 2017 (GreenAir, 2017). This reflects the fact that today HEFA is the only industrially mature production technology, while other pathways have been realized only at demonstration scale (SIP and AtJ) or are not ready for production at all. The portfolio of fully developed production technologies that can contribute to short-term deployment of renewable jet fuel is very limited, and more development efforts are required to enlarge this portfolio and, thus, enable the future ramp-up of production through sustainable and scalable technologies.
