Charcoal Substitutes
From PyroGuide
Charcoal substitute for black powder is a compound which, when used in place of charcoal in black power or sulphurless black powder, will yield near equal performance of the composition. The reason using other than charoal, is the repeatability of the performance, when used for lift or drive. But, for spark formulations there probably is no substitute.
Nitrates with organic fuels are trickier than chlorates or perchlorates. Burning speed seems to be much affected by oxygen functionality of the fuel.
Hydrocarbons
Either aliphatic, or aromatic hydrocarbons without oxygen functionality (R-OH, R-COOH) will not work.
Carbohydrates
Some, but not all carbohydrates with oxygen functionality (R-OH, R-COOH) will show near equal performance with charcoal. The only drawback of virtually all carbohydrates is their hygroscopity.
- Saccharose, yes: Candy propellant
- Sorbitol, yes: Candy propellant
- Ascorbic acid, yes: Golden Powder
- Schellack, no: Slow burning speed
Phenolic compounds
US Patent H000072 presents a variety of phenolic (Ar-OH) materials to be used as charcoal subtitutes. Burning speed of the substitute composition is compared with black powder made with maple charcoal. Some, but not all aromatics with oxygen functionality shows near equal or even better performance than maple charcoal. Compounds without oxygen functionality seems to be totally unsuitable. It is of interest to note, that sulfur will render some compositions useless. The patent discusses more on the subject.
Table 1: Some compositions (with prices relative to quinizarin, Source:Sigma Aldrich)
| BP | Comp 1 | Comp 2 | Comp 3 | Comp 4 | Comp 5 (useless) | |
| Potassium Nitrate | 75 | 75 | 75 | 75 | 75 | 75 |
| Sulphur | 10 | 10 | 10 | 10 | ||
| Maple Charcoal | 15 | |||||
| Quinizarin "$1" | 25 | 15 | ||||
| Phenolphthalein "$1.2" | 15 | |||||
| Fluorescein "$2.5" | 15 | |||||
| Anthraflavic acid "$80" | 25 | |||||
| Burning speed [cm/s]: | 0,58 | 0,53 | 0,93 | 0,62 | 0,64 | 0,08 |
http://www.freepatentsonline.com/H000072.pdf - Organic substitutes for charcoal in black powder