Globally, aviation accounts for about 2% of total greenhouse gas emissions. Therefore, the industry is making every effort to find solutions to curb the climate impact of air transport, which is expected to increase with every year.
Growth in global air transport means that the industry’s greenhouse gas emissions are increasing. Consequently, the aviation industry needs to take action to achieve the objectives of the Paris Agreement. In this connection, new and progressively more sustainable aviation fuels play a key role in reducing the climate impact. Optimisation, improved operations and infrastructure as well as the development of new technologies are, however, also crucial to reducing aviation emissions.
That is why DCC & Shell Aviation is today committed to Green Power Denmark’s PtX partnership, just as we support Arcadia eFuel’s ambitions for PtX production in the city of Vordingborg and a development project at Aalborg University converting sewage sludge and wood waste into sustainable fuels for the air transport and shipping industries.
How we optimise our operations
In Denmark, DCC & Shell Aviation has been working on optimisation and improvement of our day-to-day operations and infrastructure for a long time.
At Billund and Copenhagen Airports, our refuellers and dispensers today run on the biofuel HVO, hydrotreated vegetable oil, which reduces CO2 emissions from the fuel by up to 80% because it is made from biowaste instead of fossil sources. And very soon, we are launching the first electrically powered refueller in a step towards electrifying our fleet at the airports.
We are currently also using the natural gas-based GTL fuel for our tankers at the remaining Danish airports. GTL is cleaner-burning diesel fuel, which is, for example, improving the working environment for our employees and preventing downtime.
The greatest potential for reducing CO2 emissions in the aviation industry is to replace fossil jet fuel by more sustainable fuels. This is already being done by means of SAF; sustainable aviation fuel. SAF is a synthetic aviation fuel made from waste biomass, such as waste cooking oil from the food industry. The great advantage of SAF is that it can be used at once by the entire global fleet of aircraft and become part of the existing fuel infrastructure in and around the airports.
The pure SAF component is also called synthetic paraffinic kerosene (SPK), but it has yet to be approved by engine manufacturers for full use. Consequently, SAF is called a drop-in fuel which may be mixed with conventional JET A-1 by up to 50%. Airbus and GE Aviation, among others, are, however, testing flights on pure SAF. At a 50/50 blending proportion, SAF is classified JET A-1 and identical to fossil JET A-1. The only difference, then, is that up to 50% of the product comes from more sustainable sources.
How SAF reduces CO2 emissions
The recycling of waste biomass into fuel is a major step in reducing aviation CO2 emissions. When, for example, recycled cooking oil is used for aviation fuel, such fuel is effectively considered CO2 neutral.
That is because the cooking oil is derived from plants having absorbed CO2 equal to the amount emitted by the combustion of the fuel. As the combustion is part of a circular, biological system, where it becomes available to new plants, no more CO2 is, in principle, added.
However, the production and transport of SAF and waste biomass still emit CO2. Taking the entire life cycle into consideration, SAF emits about 80% less CO2 than fossil aviation fuel.
The SAF supplied by DCC & Shell Aviation to, for example, Sonderborg Airport and Alsie Express is produced by one of the world’s leading producers of bio-based fuels, Finnish Neste.
Ny teknologi driver luftfartens reduktioner
De kommende år og årtier vil nye teknologier og energiformer spille en central rolle i at gøre luftfarten fri af fossile brændstoffer. Allerede nu bliver hver ny generation af fly mere effektive og brændstoføkonomiske. Og da brændstoffet er den primære årsag til luftfartens CO2-udledning, er det en vigtig udvikling.
Men særligt vil det at erstatte fossilt flybrændstof med low carbon og på sigt no carbon-alternativer få enorm betydning for en mere bæredygtig flyindustri. Samtidig arbejder fly- og motorfabrikanterne målrettet med teknologi både til at elektrificere fly og til at benytte renere, alternative brændstoffer som flydende brint. Det er dog en indsats, der kræver massive udviklingsinvesteringer og etablering af en ny infrastruktur i lufthavne.
Power in the form of liquid fuel – Power-to-X
Aviation electrification is today limited by the weight, size and relatively limited energy capacity of batteries. Therefore, electrification is primarily expected to be relevant to light passenger jets.
Both regional and mid-sized jets show great potential for green hydrogen or fuel cells. Such technology is today known as Power-to-X technology and it possesses the greatest potential for reducing the aviation industry’s CO2 footprint. Power-to-X is a high-tech process which converts green wind, solar and hydro power into liquid fuel, for example aviation fuel. This is done by means of electrolysers where green power is used to split water (H20) into H2 /green hydrogen and O/oxygen.
The hydrogen may then be used either directly as fuel or converted to liquid fuel in a carbonisation process. Carbonisation requires CO2 either collected from bio plants or from the atmosphere, the latter called direct air capture (DAC). The carbon (C) from the CO2 is combined with green hydrogen to form C-H compounds in what eventually becomes, for example, green aviation fuel. Power-to-X production on a major commercial scale and safe handling of liquid hydrogen require significant investments and continued development. Denmark is among the leaders in this connection.
Book & Claim: How to make SAF part of infrastructure
A massive deployment of SAF and future even greener aviation fuels in Denmark and internationally requires a sustainable and stable supply chain which integrates with the existing fuel infrastructure. The alternative would be the establishment of a completely new, parallel infrastructure, which would solely handle SAF, etc. Such solution would significantly increase CO2 emissions and result in inappropriate and cost-intensive logistics.
This is where the book & claim principle comes into play. Book & claim is a model similar to the one we know from green electricity in the Danish power grid, where the purchase of green electricity, or in this case SAF, is made separately from the physical product. The customer claims, so to speak, a certain share of a total pool of SAF already supplied to the fuel infrastructure of Danish aviation. The supplier books the purchase in the system generating a unique certificate which guarantees delivery to the customer and that a specific amount of SAF is sold only once.
In a future when SAF is expected to constitute a still larger share of the fuel supply, the book & claim model is both sustainable and realistic with respect to supply. Unlike today, when DCC & Shell Aviation Denmark supplies SAF directly to individual customers because we are at an early development stage, making significantly larger deliveries across the country to airports and private customers will not be an option.
In this scenario, SAF will instead be supplied to the fuel system at specific airports. The amount will be recorded and verified, after which the concrete CO2 emissions from the fuel will be calculated. Customers’ specific purchases and consumption of SAF, and the resulting reduction in emissions, are then certified based on the total volume.
Book & claim has yet to be accepted and disseminated as the general and unifying model for controlling and managing a large-scale rollout of SAF globally, but Shell, among others, is cooperating with Accenture and American Express on a digital book & claim platform.