TECH STOP Aviation gasoline, also known as avgas, can only be used with engines specifically designed for its use, hence non-turbine engines. Therefore, this type of aviation fuel is not as widely consumed as the kerosene based fuels Jet A-1, Jet B and their counterparts.
Avgas is consumed mostly in the piston engines of older sports aircraft and private planes that require a leaded fuel with a high octane number. Currently, the only option on the market is the avgas 100 LL (low-lead) and it is highly expensive due to relatively low demand, an extensive supply chain and stringent quality controls. The use of motor gasoline (mogas) has also impacted the avgas price, yet mogas has not seen a large boom in the industry due to the complications and necessary changes needed to the engine in order for aircraft to be able to use this gas.
Biokerosene
The 2018 estimated consumption of jet fuel by the entire industry is 94 billion gallons. Naturally, the main argument for using a biokerosene fuel, which is derived from vegetable oils and/or animal fats, is to create a reduction in the carbon footprint caused by the airline industry. Currently, aviation causes around 2% of global emissions and this is expected to grow to roughly 3-8% by 2050 depending on who you ask. IATA (The International Air Transport Association) has a challenging goal of halving the CO₂ emissions by 2050 while the industry continues to grow. Aside from focusing on developing and producing more fuel efficient aircraft, changing the type of fuel used is one of a few options to help achieve this goal.
One of the two currently used methods for producing “drop-in” jet-fuel (one that can be interchanged with a traditional blend) is by using plant sources such as algae, jatropha curcas, tallows, and babussa and camelina oil to a create a bio-SPK biofuel; SPK stands for synthetic paraffinic kerosene. This method utilizes cracking and hydroprocessing in order to get results and the industry has been experimenting with these alternatives since the late 2000s with approval for commercial use in 2011. Now the focus is on creating sustainable biofuels, that is fuel that does not take away food supply from animals nor are large consumers of top-notch agricultural or water space while being economically feasible. Let’s take a look at how a few of these biofuels are performing.
Algae was tested by a few major players around 2008 and unfortunately hasn’t shown much promise since then to be a long-term source of jet fuel. A sizable amount of early producers have pivoted their business strategy into other arenas. Camelina seed based biofuel (50-50 blend) was tested by the US Navy in 2010 but hasn’t gained much traction over the years. It has been shown that the current low cost of traditional fuels when compared to the production cost of this alternative makes it cost-prohibitive to roll out this biofuel to the commercial aviation industry without government subsidies placed on camelina crop production and taxes imposed on conventional fuel blends.
All in all, the main inhibitor to the growth of these biofuels is pricing and therefore demand. Simply put, it is expensive to be green since these biofuels are being produced in batches due to low levels of demand by the industry. Companies and organizations are dipping their toes into different options but none have taken the plunge as a viable long-term and reliable source has yet to be discovered. Only the future will tell.
The last two weeks of January focus on fuel economy and looking at options to bypass fuel altogether, electric planes.
