Since it's less efficient than modern processes I don't think it had any application besides the fun of a DIY project.

Though I guess it's an interesting way to obtain nitric acid for individuals, since access to it is quite restricted otherwise.

it's "less efficient" only because there is currently no meaningful externality priced into the natural gas supply chain. This might change in the future ;)

Is it? I can buy a pallet of 500ml bottles from a science supplier. Hell, I can buy a bottle from Amazon for $30.

Who in their right mind would deliver that?

Feel free to try that and report back lol

>since access to it is quite restricted otherwise.

There's a reason for that, of course.

That's what fertilizers are for. And the production of fertilizer was the point of Birkeland–Eyde process.

Where does the nitrogen go in a closed system? I'm not aware of a natural process that converts fixed nitrogen back to N2. Doesn't mean a process doesn't exist, I just don't know about it.