Justin Gombos wrote:

But since you bring it up, a gasoline engine can actually burn
(bio)diesel safely, as long as it's mixed with at least 90% gasoline.
It would essentially be the equivelent of very high octane gasoline.
Are you familiar with those "octane boosters" sold in 8 dollar retail
bottles with all the fancy graphics? Lookup the MSDS on it - it's
only kerosene (iow, fuel oil)

There are problems with biodeisel at altitude. It may never be
viable for aircraft. Pie in the sky is for people on the ground.