By 2020, global international aviation emissions are projected to be around 70% higher than in 2005 and the International Civil Aviation Organization (ICAO) forecasts that by 2050 they could grow by a further 300-700%1. Emissions from international aviation has increased substantially as a result of higher demand and consumption of jet kerosene, what also contributed to a 0.7% greenhouse gas emission in the EU in 20172. The Carbon Offsetting and Reduction Scheme for International Aviation, or CORSIA, aims to stabilize CO2 emissions at 2020 levels by requiring airlines to offset the growth of their emissions after 2020. Due to the fact, that by using graphene-based materials in composite aeronautical structures a weight reduction can be achieved, less fuel consumption will be realized3. It has been reported that 1 kg of mass reduction in an aircraft can save over 2900 liters of fuel per year1. This – on the long-term scale – contributes not only to the stabilization but also to the reduction of the CO2 emission levels. A calculation in Table 2.1b was carried out under the assumption, that conventional state-of-the-art de-icing systems will be replaced by the proposed project results. The mass reductions obtained by integrating the de-icing functionality into the aircraft structure itself results in considerable fuel and CO2 savings. Additional mass saving effects by integrating other functionalities, as lightning strike protection, fire retardancy and water barrier have not been accounted yet. Further savings of fuel could be realized by the fact, that GRAPHICING used for IPS will consume less energy compared to conventional bleed-air systems. Electric energy will only be produced by the APU resulting in a 35%-50% energy requirement reduction compared to a conventional bleed air system. A bleed less Aircraft will further produce at cruise conditions a 1% – 2% engine efficiency improvement at cruise conditions (Ref.: Boeing 787 Dreamliner no-bleed system4). About one fifth of this value can be attributed to an all-electric IPS. For comparison the total estimated CO2 savings (by fuel savings) of a MEA concept based on A320 are recorded in table 2.1b as well. The definition of a more electric aircraft (MEA) can be derived as an aircraft where the majority of the systems or a higher percentage of systems compared to conventional aircraft are powered electrically5. An all-electric IPS (wing and tail IPS) will be a main component of a MEA and will result to about 20% of total electric power consumption. It can therefore be expected that the replacement of the bleed air IPS by an all-electric GRAPHICING IPS will generate net CO2 savings of about 1,4%-1,6% in a typical LPA like A320 (by mass reduction, and energy savings). These values correspond closely to the calculated savings in a MEA concept. For larger aircraft (777) those net saving could well be close to 3%. For a small GA airplane replacing a TKS system would result in 0,5% CO2 savings.
Estimated CO2 savings based on Aircraft mass and energy reduction by replacing conventional IPS systems with an IPS system based on GRAPHICING:
|Replacement of IPS system||Mass savings by substituting state-of-the-art IPS systems by GRAPHICING||Assumptions/ References||CO2 reduction potential by mass savings||CO2 reduction potential by Fuel & Energy savings||Net savings of CO2 emissions|
|TKS- system (GA)||TKS system and TKS fluid:55 kg savings||Bonanza Beechcraft7||0.61%||-0,1%||0,51%|
|Conventional Bleed Air system (LPA A320)||72 kg mass savings for A320 (ATA chapter 30)6||No valves, ducts, heat exchangers required||0.8%||+0,6 – +0,8||1,4% -1,6%|
|Conventional bleed Air system LPA 777||286 kg mass savings for 777(ATA chapter 30)6||2,6%||+0,4 – + 0,6%||3,0% – 3,2%|
|MEA for comparison(baseline A320)||8,1 – 9,9% in total48||1,6% – 2%|
2 Annual European Union greenhouse gas inventory 1990–2017 and inventory report 2019
3 Soutis C. Carbon fibre reinforced plastics in aircraft construction. Materials Science and Engineering: A. 2005; 412(1-2): 171-176.
5 Improving the operating efficiency of the more electric aircraft concept through optimised flight procedures, CEAS Aeronautical Journal, June 2019, Volume 10, Issue 2, pp 463–478
7 Tim Lammering: Integration of Aircraft Systems into Conceptual Design Synthesis, Dissertation, Rheinisch-Westfalischen Technische Hochschule, Aachen, 2014