Making Gunpowder out of Corpses

Question

Story Info

On a fallen world that still has firearms. Society is still advanced in a way, but is more tribal/feudal in nature. There is an armed priesthood that preaches and deals in death. To the unbelievers they are called the Powder-Priests or Death-dealers, to their followers they are called (haven't given them a cool name yet). The Priesthood forever walks the towns, villages and battle fields in search of new bodies to add to the pile, for you see they believe that in battle Death must come from Death itself. They are under the impression that items containing remains of the dead become beacons for it; that when it enters the body life will fade. They take the bodies to the powder fields found close to all towns (think graveyards except the bodies are out in the open) to make what they call the essence of death; it is what you would call gunpowder. The Priests sell the powder to all factions in the world believing that they will be the cause of their own destruction, the other factions take the powder not caring either way.

The Idea

The idea is that the Powder-Priests have these powder fields filled with bodies, so that they can make gunpowder. I read a book from Japan about the Sengoku period and a group that did this (I think they were monks) and thought that it would be cool to use this in my own book but the book that had the info has been lost and I’m having trouble getting the right way on how they did it. I think it's bodies, urine, and charcoal and leave it for a few years? (I tried looking it up; swear I’m on someone’s watch list now.) But I have no idea what the technique is or that I have the right… ingredients.

The Question: How to make Gunpowder out of Corpses?

This one was a little bit on the odd side for me to ask, but if it helps me make a better book I’m fine with it (hears knock on door FBI opens up). I know that the book I read was based on real events and I have also read somewhere else about this being done before (or something similar)... I think the French? I’m also aware that there are better ways of making gunpowder, but this way fits perfectly with the group and their ideals, so I think I won’t change it.

Answer 1

Gunpowder requires potassium nitrate and charcoal. Charcoal is fine to make from corpses (bone charcoal is good charcoal) but potassium nitrate is trickier.

One can make potassium nitrate from manure. It is a byproduct of bacterial decomposition of manure and urine. It is water soluble and so one of the original methods to get saltpeter was to dig up the earth floors of old animal barns, then wash the saltpeter out of it, then dry up the wash water and collect the saltpeter. When they scaled up production of saltpeter they took plant waste (raw manure) and made fermentation vats. They added some barn earth as a starter culture.

In your fiction, have the priests own a starter culture of bacteria which produce potassium nitrate. As with the above described saltpeter vats, the priests can inject the corpses with this so as they decompose they will turn in part to saltpeter. I think it might make sense for them to process the corpses some first, defatting them - this would be a process similar to how mummies are processed.

Answer 2

I looked around, and unless we are made of something very interesting, no, not even as corpse we make for good gunpowder ingredients.

As living beings, we can contribute with our own waste: urine

Explanation, from the link:

Gunpowder is comprised of 75% potassium nitrate, 15% charcoal and 10% sulfur. While charcoal (historically made with wood) and sulfur (historically dug from the ground around volcanoes) have been relatively easy to obtain, potassium nitrate is not commonly found in nature. Early sources were found in caves where guano (bat poo) had combined with minerals from the cave walls; soaking and filtering the guano was an effective method, but there are only so many caves, and so much bat poo.

With an increasing need as gun warfare became more common, by the time of the U.S. Civil War, men were manufacturing potassium nitrate in huge amounts. One process, known as the French method, involved mixing manure with ashes, straw and urine; the mixture would be tended for many months, perhaps even a year, then filtered through more ashes and a bit of water. A second process, called the Swiss method, involved placing a sandpit directly under a stable; only the urine made it into the sand, which would be harvested and filtered in the same manner as the French method. Either way, it had to be a tough job.

Survivalists and gun enthusiasts today enjoy (well, maybe) making their own gunpowder. For the potassium nitrate, one recommended process is to put a lot of manure in a large drum with a drain, valve and filter screen installed at the bottom. Pee into it. Freely. Then add water for a total of about 300 gallons of yuck. Place it in a safe spot (far away from the house, if possible). After 10 months, pour it out onto shallow trays to dry.

Separately with a mortar and pestle or hand-cranked mill, grind charcoal (all natural, no Match Light) to a powder and set aside. Do the same with sulfur, which can be purchased in home and garden stores. Finally, grind the potassium nitrate. Experts warn not to grind the ingredients all together, since that would possibly explode in your hands.

For storage, the best minds suggest mixing the three powders together then adding a little stale urine so the mixture has the consistency of biscuit dough.

Answer 3

Dehydrate them!

Gunpowder is carbon, sulphur and saltpetre. Saltpetre can be made from urine and faeces. After extracting those from the corpses, add concentrated sulphuric acid, (which can be made from sulphur saltpetre) which should break down the corpse into mostly carbon.
Then just add sulphur.