[amelius]

> "The raw energy density of liquid ammonia is 11.5 MJ/L, which is about a third that of diesel."

Yes, but that's assuming you'd burn it, I suppose (not a chemist). In this case, you're extracting H atoms using a different process, and I imagine that this wouldn't utilize the full raw energy density of ammonia.

[pjc50]

Looking at the process as a whole, it is burning - or at least oxidation. Starts with NH3 and ends up with H2O and N2 (preferably not NO2). The energy liberated from the bonds is the same. The amount of energy available at the wheels depends on a lot of fine details of how it's used.