News this week from the world of alternative fuels. ASTM has given the OK for fuels made from non-oil sources to be used in aircraft. Exciting stuff, yes? Let me explain…
 

ASTM International sets the standards for the chemical properties and production methods of jet fuel. Currently, we in the industry use “Jet A” or “JetA-1” fuel for most commercial airline flights. The key attributes of this fuel are listed in the table to the left. Obviously, this fuel comes from oil at the moment. In the last few days, ASTM has approved the use of a fuel on commercial flights that doesn’t come just from oil.

Their latest specifications allow for, among other things, a 50% mix of fuel made from the gas-to-liquid process to be used. This process, also known as GTL, takes natural gas and turns it into a liquid fuel. Just like the name suggests! In fact, this fuel standard allows any fuels using the  "Fischer-Tropsch" process to be used in a mix with traditional fuels.

Now, gas-to-liquid fuel has some advantages over normal old fuel made from oil – it has lower particulate emissions and a slightly higher energy density (you can fly a little further on the same quantity of fuel). But of course, it is still using fossil fuels and the production of the fuel takes energy and results in CO2 emissions as well.

But it is a good step. Now that ASTM International have approved this fuel mix, the door is opened a little wider to the real environmental pay-off that comes with sustainable biofuels.