by Dr. Christoph Weber, CEO JATRO AG, Frankfurt & Mitchell Hawkins, CEO BioJet Corp, Santa Barbara, CA (JATRO/BioJet)  Biofuels provide a viable alternative to conventional fuel and enable airlines to reduce their environmental impact. Over the last three years biofuels for aviation have matured from novelty towards commercialization. JATRO and BioJet have been pioneering ways to develop and commercialize biofuels from plants such as jatropha and camelina that do not compete with food crops for land or water. These sustainable fuels, which have a smaller lifecycle carbon footprint than petroleum-based products, have proven that they can efficiently power commercial flights.

… Bio jet fuel created from jatropha and camelina seeds has demonstrated in numerous flight operations that hydrotreated renewable jet fuel reduces carbon emissions (CO2) by up to 85% compared to conventional petroleum jet fuel. The decrease in CO2 emission for Jatropha based bio-kerosene is attributed to the high cetane number and the presence of oxygen in the molecular structure of the jatropha fuel. It should be fair to acknowledge that the positive effect on CO2 emission reduction alone translates into significant Green House Gas (GHG) savings. All other things being equal, the sheer magnitude of this GHG reduction alone more than justifies the gradual transition towards a green fuel blend in the aviation industry. Add to this the basically sulfur free fuel properties – and jatropha based bio-kerosene demonstrates a significantly better environmental performance than fossil fuel.

… NOx emissions vary significantly across the flight cycle, with the highest levels generated at take-off when the air entering the combustor has the highest pressure and temperature, and the peak combustion temperatures are highest. As a result, NOx are for the most part dependant on aircraft engine technology and flight pattern instead of fuel properties. Thus, NOx emissions can primarily be reduced through improvements in combustor and engine technology as well as airframe aerodynamics and modified takeoff and landing procedures.

As it turns out, the negative side effects of NOx emissions are by and large unrelated to the underlying fuel properties. However, brought forward in a biofuel related context, critics suggest that green aviation fuels are bad because they don’t reduce lethal NOx emissions. With no evident causal or scientific link, it becomes obvious that this type of criticism is not really adressed against biofuels but against commercial air travel in general.   READ MORE Download paper (includes charts, graphs, illustrations)