Every few years we report on developments in alternative aviation fuels. It’s hard to answer the question “Are we there yet?” because a second question always arises, namely, “Are we where yet?” Since our last report the “where” has started coming into focus. Increased tensions around the threat from climate change are driving demand for technological advances to “save the planet.” We no longer talk of “alternative fuels”, but rather “sustainable aviation fuels” (SAF). Further, an industry goal, or “where” has been set: netzero CO? emissions from flights by 2050. Billions of dollars are being wagered on alternative paths to SAF and low emission technology.

Aviation accounts for around 1 billion tonnes, or 2-3% of global CO2 emissions. According to Air BP, “a return flight between London and San Francisco has a carbon footprint per economy ticket of nearly 1 tonne of CO?. With the aviation industry expected to double, with over 8 billion passengers, by 2050, it is essential that we act to reduce aviation’s carbon emissions.”

Unleaded avgas

A renewable alternative to leaded avgas is sought because avgas is expensive to produce, pollutes the environment, and is difficult or impossible to source outside the main centres of developed countries.

Lead in avgas, as used in general aviation aircraft, prevents damaging detonation that can result in engine failure.