Study finds biofuels drastically cut jet engine pollution by as much as 70pc

16 Mar 2017

NASA’s DC-8 research jet engine aircraft. Image: NASA/SSAI Edward Winstead

The scale to which jet engines on airlines pollute our planet could be drastically reduced by as much as 70pc if biofuels become the norm, according to a new study.

With thousands of jet engine aircraft driving much of the world’s globalised economy, there would appear to be no calls for any type of reduction in their numbers.

However, the effect they have on the planet, in terms of emissions, has been called into question. For that reason, research is looking into alternatives to reduce the carbon emissions.

The most likely way this can be achieved in the short term is through biofuels sourced from renewable, plant-based sources rather than solely from limited and dirty fossil fuels.

NASA-led research into the efficacy of these biofuels has found that it reduces particle emissions in their exhausts by as much as 50 to 70pc.

Throughout 2013 and 2014, large amounts of data were collected to measure the effects of alternative fuels on engine performance, emissions and aircraft-generated contrails at altitudes flown by commercial airliners.

The contrails are of particular interest to the researchers, who believe that the crystallised mixture of CO2 and ice create long-lasting, and sometimes extensive, clouds that would not normally form in the atmosphere, and are believed to be a factor in influencing Earth’s environment.

During the tests, the NASA aircraft with four jet engines flew more than 12,000m, with a 50-50 blend of aviation fuel and a renewable alternative fuel of hydro-processed esters and fatty acids produced from camelina plant oil.

Supersonic biofuel research in the works

The different types of fuel were then measured and analysed for soot content, revealing the potential for drastic emission reduction.

“Soot emissions also are a major driver of contrail properties and their formation,” said Bruce Anderson, project scientist for the study called Alternative Fuel Effects on Contrails and Cruise Emissions Study (ACCESS).

“As a result, the observed particle reductions we’ve measured during ACCESS should directly translate into reduced ice crystal concentrations in contrails, which in turn should help minimise their impact on Earth’s environment.”

The next step, NASA said, will be to test biofuels on its next generation supersonic X-plane that is currently being developed.

The team’s research has been published in Nature.

Colm Gorey was a senior journalist with Silicon Republic