Aircraft oil run with 1000LL cannot be recycled
It can be; you need a re-refiner that is set up to handle it. Typically, the bottoms product from a re-refiner’s distillation column is sold to a refinery as coker feed; that little bit of lead doesn’t adversely affect petroleum coke properties, and there are hazardous materials exemptions for re-processing schemes.
They have to refine it again anyway, so I assume the lead will come out in the refining process, just like everything else in raw crude oil?
Exactly so… just like the nickel and vanadium that arrive in the crude oil in comparable concentrations to the lead in used aviation oil.
The airport I'm at today burns it to heat the maintenance hangar…. wouldn't burning such oil release lead into the air?
Yes. The maintenance hangar at Grants Pass, Oregon’s airport burned used motor oil. An environmental cleanup resulted.
transportation and delivery costs might be less for UL fuel, because there is no need to dedicate tankers to leaded fuels. Maybe that's not a lot, but it's something.
No, avgas will still be handled in dedicated systems to avoid cross contamination and product downgrade. Even though unleaded avgas is a clean burning fuel, it has properties that would earn it demerits if comingled with reformulated mogas.
The main downsides are going to be a small (5%) weight penalty, because of the higher density of the fuel. Fortunately, volumetric energy content is comparable.
And the energy content per unit weight is even more comparable, and airplanes do care about weight.
I doubt we will win the favor of a battery fairy by 2073.
Battery technology has been improving about 10%/year. Some forecasters believe that another 10 years of such improvement will result in very usable energy densities for light aircraft. 50 years of such progress will be notable, half an order of magnitude better if that trend continues!
G100UL...I hate to see what even 10% ethanol is going to do to those very expensive and more than a little temperamental engines. If I remember right they only have to label it if it exceeds 10% ethanol.
Read GAMI’s patents, they’re online. There’s no ethanol.
We don't need the lead or the ethanol, methanol can raise the octane levels more than adequately and it isn't hydrophilic. Methanol is what's in dry gas.
But, methanol attacks aluminum and other bright metals. That why it is no longer used in mogas after some spectacular failures in the early 80’s. We’ve got even more aluminum wetted by fuel in airplanes. Methanol would be a bad thing. Even for your car, it’s best to avoid dry gas products with methanol. Instead, look for those with isopropanol (isopropyl alcohol). That’s MUCH more benign to the metals in your fuel system.
The bigger advantage is that we can run synthetic oil now.
Well, we will be able to once synthetics formulated for aircraft engines are released. The PCMO (passenger car motor oil) synthetics available now have additives that are very bad for aviation engines. Please don’t be tempted to use them in your airplane!
Exxon, I think, Used to market an aviation synthetic blend.
Yes, Exxon Elite… a nice oil package. It was only 25% synthetic. Shell’s semi-synthetic 20-50 aviation oil is 50% synthetic. That’s about the limit if you want to be able to carry the lead salts away and not have them damage the engine. Exxon thought 50% was pushing the edge a bit too much…
shouldn’t all aircraft just be deemed worthy and just give the fleet a blanket STC?
The FAA hopes to do something like that for the EAGLE/PAFI2 fuels from Phillips/Afton and Lyondell/VP-Racing. But in the first three EAGLE meetings, FAA management bemoaned that they don’t know how to do that legally… and that it may require both Congressional action and a couple years of FAA rulemaking activity. Blanket STCs aren’t a thing today, and apparently not easy to accomplish legally for the FAA.
Paul
