Aviation fuel

Single-cell superiority

After years of promising talk, plant-derived jet fuel looks to have finally taken flight. Planes powered by algae – yup, the same scum that coats ponds and fishtanks – created a stir at two of this summer’s key aviation showcases.

At the UK’S Farnborough Airshow, San Francisco-based Solazyme announced delivery of 1,500 (US) gallons (5,700 litres) of 100% algae-based jet fuel for the US Navy’s rigorous testing and certification programme. This is not insignificant. The American military accounts for about 80% of the federal government’s energy demand. Mindful of the $20bn (€15bn) spent each year on jet, diesel and other fuels, the Defense Advanced Research Projects Agency has spent $35m (€26m) trying to find a way to make jet fuel from algae that costs less than $3 a gallon by 2013. This is the same Pentagon venture arm credited with developing the internet.

Yet although Solazyme’s renewable HRJ-5 is said to meet all of the Pentagon’s renewable fuel requirements as well as the standards for commercial jet fuel, the demonstration witnessed at the The Berlin Air Show was even more impressive. Here, the EADS biofuel project showcased the world’s first actual flights of an aircraft run entirely on biofuel made from algae. Tests of the bio-powered, four-seat, twin-engine, DA42 propeller plane made by Austria’s Diamond Aircraft Industries highlighted an eye-catching side benefit: planes go further on this eco-fuel than on kerosene, resulting in 5%–10% savings.

“Due to the higher energy content of the algae biofuel, the fuel consumption of the Diamond DA42 New Generation is 1.5 litres per hour lower when compared to conventional Jet A-1 fuel – while maintaining equal performance,” noted IGV, the Potsdam-based institute whose pioneer in microalgae research and production led to this breakthrough.

Moreover, algae fuel comes without the environmental baggage associated with the biodiesel craze. Unlike soybeans or corn that have a limited harvest window, algae multiply every hour and can be harvested every day. Algae can also be grown on poor quality land using non-potable or salt water, so they don't compete for land suitable for food crops. According to IGV, the amount of CO2 released during flight is about equivalent to the amount absorbed by algae during their growth phase. “This opens up the possibility of carbon-neutral flights.”

These developments are a leap forward from the successful test flights carried out by commercial airlines in latter years using a variety of biofuel-jet fuel blends. Boeing was involved in all four tests, including a Virgin Atlantic flight using a coconut- and babassu nut-derived blend.

Grown for many years on a commercial basis for food supplements and cosmetics, microalgae is now ready for takeoffas an alternative aviation fuel. Now, it is just a question of being able to grow enough of these foul-smelling single-cell organisms to meet demand.