Fuel Of The Future

Today, I am going to look at the future of providing fuel for aviation. It is estimated that by 2026, 221 billion gallons of aviation fuel will be needed against the 95 billion gallons used in 2007 (Hendricks et al. 2011). 

Regardless of  increasing technological improvements to aircraft that I have touched upon in previous posts, fuel for aviation has been growing at a rate of 4% annually, whereas the fuel efficiencies of aircraft have been increasing at a rate of 1% annually, so addressing the source of fuel for aviation will be critical in helping to achieve  lower carbon emissions,  a goal which the aviation industry has set for itself (Hendricks et al. 2011). 

Substituting some of this fuel with biofuels such as ethanol or biodiesel, which are currently being used as in fuel in cars is not an option due to the specific fuels required for aviation. Thus ways in which biofuels for aviation can be produced without competing with arable land or freshwater resources, do not lead to further deforestation, and do not have wider environmental or social impacts have to be considered (Hendricks et al. 2011). Pagowski (2003) praised the suitability of hydrogen as a fuel to be used in aviation, despite uncertainty on how to actually implement it. A liquid, highly cooled hydrogen fuel in aircraft would render water vapour and smaller quantities of nitrogen oxides as the only emissions. 

Despite the aforementioned fuel options, there may be other factors at play which explains the relative hindrance in the development of alternative fuels for aircraft in comparison to other motor vehicles. Kivits et al. (2010) attribute this to the infrastructure involved. A change in transport fuel will make current aircraft and airport infrastructure unsuitable. The paper names privately owned airports as reluctant to finance and accommodate future air traffic operations, which contributes to aviation being the slowest of major transport systems to adapt to a carbon constrained future. 

The airliner manufacturers (Airbus and Boeing) themselves have been named as responsible for the set back (Kivits et al. 2010). The airframes of many new aircraft in development and production are built around the use of carbon based fuel and turbo engines. It will take Airbus and Boeing many years to pay for projects like the Boeing 787 Dreamliner and Airbus a380 (20 years!). These are planes which represent cutting edge technology and concern for the environment, and that's even before they make a profit on them! Therefore potential investment in research and development into new plane shapes and fuel types can not be justified financially. 

Though not looking dissimilar for other aircraft, the relatively larger size of the a380, and the more powerful engines on the Boeing 787 Dreamliner, meant that airports had to invest in their infrastructure. Either upgrade or lose out. What would have been done if these aircraft were significantly different? Would they have even been built? As a compromise to environmental efficiency, the proposed Boeing 777x has wings which fold in, so they fit into many smaller airports that the 777 currently serves. 

The development of alternative aviation fuels is an important priority, however without even looking that much into the subject,  it can be seen that there are many apparent set backs when considering the wider effects of going about making such changes to fuel and aircraft efficiency. Turbo engine powered aircraft have been operational since the 1960s and there has been little variation. The simple question of looking at other energy sources for planes requires a whole technological "paradigm change" as Kivits et al. (2010, 3) puts it, something that no one is prepared to do at the moment. Rather than ignoring the issue, biofuel mixes, which wouldn't require great changes to current aircraft or ground infrastructure are currently being investigated and tested.

When putting the previous post into context, it is easy to see why investment is made on smaller environmental initiatives (such as interior cabin materials), as this is something that funding probably permits and does not require substantial infrastructural changes.   

Biofuel made from algae mixed with normal jet fuel have already been tested by airlines!