CSIRO on brink of breakthrough in enabling hydrogen fuel cell supplies, page-4

Ammonia to hydrogen is pretty easy, by cracking process to make H2 + N2. There will be some NOx as well (and leftover ammonia) but only trace amounts with a good reactor. That process can be almost 90% efficient and relatively cheap. The key is to then separate the h2, and they give no info about that other than membrane based.

membrane separation might be a palladium (v expensive so unlikely), but my guess would be an electrochemical h2 pump (essentially a modified fuel cell).. that way it can also make it close to 700 bar for filling stations too.

But in all cases u still need to make the h2 (or ammonia) first. Competition arising is betw lng and ammonia as a carrier. Room for both in the market I reckon but I would bet on hazer being cheaper..