Still think jet fuel is the wrong thing to be looking at with carbon fuel emissions.

It is technically more feasible on a small scale because jet (and turbine) engines will burn basically anything, with jet fuel being a mixture of kerosene like hydrocarbons.

But iirc both land vehicle and shipping outclass airplanes in total emissions.

Cars & Trucks can be (for much cheaper) replaced by proper mass transit like high speed rail.

And I'm surprised cargo ships still run mostly on novelty sized diesel engines. Would be interesting to throw a small ultra safe nuclear powered engine on one of those or even just enforcing better fuel use instead of spamming low grade MDO.