Information Request: Haber-Bosch v. Cyanomede

[TheYoungPretender]

Gentles, I'm looking for some more detailed information on German nitrate sources during the Great War. In particular, I'm looking for information concerning the relative efficiencies of Cyanomede vs. Haber-Bosch that are web accessible and not behind a paywall. In this case, I'm specifically interested in it in the realm of making explosives, but I will need it for fertilizer productions as well.

The industrial-scale implementation of Haber-Bosch changed a great many things, apart from ammonia production and nitrate synthesis. Implementation seems akin to the space program in a way, in that the need to do very (for the time) high pressure reactions at a very large scale, with a bunch of knock-on effects. I'm considering a timeline where Bosch, who was instrumental in figuring out how to make Haber's discovery work on something bigger than a small demonstration unit, get hit by a tram sometime around 1900.

 

[Insider]

As for cyanamide I researched it for my story. There are two upsides. It is more likely to be used as an fertiliser rather then explosive it requires one additional step prior to Oswald process. Further it gives plants not just bioactive nitrogen but calcium as well. As for the downsides:

"One of the parent substances was calcium carbide. It was tricky to transport, as it had unsavoury habit producing explosive acetylene when wetted, which is fun when you are eleven years old and try to make a "boom", but things get troublesome when you reach industrial scale. Use of carbide made the fertiliser quite expensive as calcium carbide could be made only with huge amounts of electricity."

 

[TheYoungPretender]

As for cyanamide I researched it for my story. There are two upsides. It is more likely to be used as an fertiliser rather then explosive it requires one additional step prior to Oswald process. Further it gives plants not just bioactive nitrogen but calcium as well. As for the downsides:

"One of the parent substances was calcium carbide. It was tricky to transport, as it had unsavoury habit producing explosive acetylene when wetted, which is fun when you are eleven years old and try to make a "boom", but things get troublesome when you reach industrial scale. Use of carbide made the fertiliser quite expensive as calcium carbide could be made only with huge amounts of electricity."

Excellent, I had not known of the more... explosive... problems. I'm wondering the rough comparison of man hours and electricity: I know it's "more", I'm wondering "how much?" Are we talking arc method amounts?

 

[Insider]

Excellent, I had not known of the more... explosive... problems. I'm wondering the rough comparison of man hours and electricity: I know it's "more", I'm wondering "how much?" Are we talking arc method amounts?

The Frank–Caro process, also called cyanamide process, is different from arc method called Birkeland–Eyde process. From the title I thought you are asking about the cyanamide process. These are two distinct reactions here. And as for amounts ... it is very hard to say. First of all what you want to get in the end? What you have in a cheap supply? And then you have chemistry to combat with, to quote myself...

theoretically, you could get 3.7 times the mass of ammonia while converting it to nitric acid. However, the reaction has two possible ends – on one, you end up with nitric acid, while on the other it reverts back to nitrogen and water. There are ways to make the reaction output go more favourably in the way you want, using the right catalyst, removing the desired product as soon as possible so it would be "missing" from the reactor, but these methods can be only partially effective. You will always loose some. So the actual weight rate is more like one ton of ammonia to 2.5 tons of nitric acid.
When one makes explosives out of nitric acid, again the mass is added.

 

[TheYoungPretender]

The Frank–Caro process, also called cyanamide process, is different from arc method called Birkeland–Eyde process. From the title I thought you are asking about the cyanamide process. These are two distinct reactions here. And as for amounts ... it is very hard to say. First of all what you want to get in the end? What you have in a cheap supply? And then you have chemistry to combat with, to quote myself...

I'm aware of the difference in the processes, and the massive electrical needs of Birkeland. I'm more interested in the source of your numbers for my own digging.

 

[Insider]

Frank-Caro has also huge thirst for electricity. First you have to produce calcium carbide, then to convince it that it is worth binding with nitrogen. Still it is more effective than arc method, and more scalable as well, but you end up with fertiliser. If you want to make explosives going for arc method where you end up with Nitrogen Oxide might be more effective.

The ratios I have quoted are Oswald process of course. But the same problem occurs with most of chemical reactions. Essentially the same reaction can end up with various results, creating wastage or impurities.