Homemade alder and willow charcoal for gunpowder manufactureEdit
Formula: mixture with variable composition, generally of empirical formula C8H4O.
Description: Charcoal finds widespread use in pyrotechnics. Many types of charcoal exist, each with its own properties. It is a complex organic substance containing moisture, ash, carbon, hydrogen, oxygen and a variety of volatiles. All of these elements have a vital use in fireworks. Charcoal made from willow or grapevine is considered great for black powder, while hardwood charcoals e.g. pine charcoal are commonly used for spark effects. The particle size and the process used to make the charcoal also play an important role in the quality of the charcoal for a specific purpose. Very fine charcoal floats in air and is therefore sometimes referred to as 'airfloat'. Because charcoal is a very important chemical it is listed in the Beginners pages .
Hazards: Fine charcoal dust is easily breathed in, and a dust mask should be worn when working with it. Freshly prepared charcoal can be pyrophoric even when not powdered and it must be allowed to stand for a day at least before it is used in any compositions.
Sources: Barbeque briquettes are mixed with clay and are not suitable for making black powder. Charcoal can be purchased from supermarkets, BBQ supply stores and directly from online pyrotechnic chemical suppliers (ie. Skylighter ). Charcoal can easily be prepared at home and a basic tutorial is outlined below.
Hazard Symbols: Xi
See the Charcoal Suitability Table for additonal information on different kinds of charcoal.
Where to buy: You can buy High Quality Hardwood or Willow Charcoal Powder (C) from http://www.HobbyChemicals.co.uk
Wood There are various types of wood that can be used in black powder , and all perform differently. Willow, Alder, Birch, Fir, Oak, Beech, Ash, Pine, Balsa are just some of the woods that can be used to manufacture charcoal and if charred properly it will produce excellent quality black powder . In this example the wood used is balsa wood which can be bought from hardwareâ€™s and hobby stores. It is very soft and light weight wood, which is a little expensive, however you can actually make a reasonable amount of very fast burning black powder with a small amount. The piece in the picture is 80cm long, 10cm wide and 1cm thick and cost $5.95.
Cooking container Any pot with a lid will work, as the wood needs to be charred without (or as little as possible) the presence of oxygen. In this example we are using an old paint tin with a few holes drilled into the lid to allow the gases to escape.
Heat source You need a moderate heat source to char the wood. Too much heat will burn the wood completely through using most of it's fuel source for your black powder . Basically the charred wood when finished should be black to dark brown in colour. Either place your container on an open fire or like in this example, as we are only making a very small amount, on the BBQ gas burner.
|pyrolysis, the process of heating the wood in the absence of oxygen. Every few minutes or so give the paint tin a 1/4 of a turn to allow the wood inside to char evenly.|
|ball mill if there is a chance it may still be hot inside the charred wood.
In the example only half of the balsa wood was added to the paint tin, and it yielded about 20 grams of very high quality charcoal. If making standard 75:15:10 black powder you can make about 123 grams of very hot and very fast burning black powder . Not bad for about 20 minutes work.
Most people who make high quality black powders use it only in black powder rockets , cylindrical shell breaking and so on where performance is required. Standard black powder is used for other general purposes like dusting stars to assist in ignition at effect time.
To get good pine charcoal, the heating must be stopped when the tar production is very minimal at the temperature of 450'C. The gas flame is observed small and 'dirty' at this point, tar seems to be 'watery'. The whole setup is allowed to cool at least one day before opening, otherwise the contents will be combusted. After you open the container, crush the contents with a large shovel, then shift out coal with a kitchen sieve, crush again, shift again, until all the coal is reduced into powder. The coal made this way is in a form of little needles, just perfect for long hang-time comet/star effects. In the comp mixing process, a little acetone should be added for dissolving resins left in the coal, to make a path for the oxidizer -water solution into coal.
There are alternative methods for heating up the retort. The gas escaping, could be returned in a round burner heating the cauldron, wood would be dry-distilled on their own energy, the gas could be mixed with LPG gas. Electric heating is also possible. Be careful, do not get incinerated or electrocuted.
The yield of wood tar is 1-5 litres, varying greatly with the resin content of the wood. Save the tar for other purposes. It is great for preserving wood but it is carcinogenic, so it must not be ingested.
From U.S. Geological Survey Scientific Investigations Report 2004-5292: Aliphatic components are distilled off or converted to aromatic species early in the charring process. No porosity develops in samples with heating at 250â€™C, even though substantial material loss does occur. At 300â€™C, both pine and poplar woods develop porosity and reach maximum aromatic carbon percentage after 8h of charring, whenafter the percentage starts decreasing. At 350â€™C and above there will be development of porosity and rapid decrease in aromatic carbon percentage after the first hour of heating. The appearance of porosity does coincide with the loss of aromatic carbon, which indicates that porosity does not develop, until after the conversion of aliphatic to aromatic carbon has ceased and aromatic carbon is being removed. There is some indication that prolonged heating may cause fused-ring structure to coalesce and reduce porosity. Wood consists of roughly two thirds of cellulose and one third of lignin. In lignin, three types of phenylpropanoid moieties may exist: Parahydroxyphenyl, guaiacyl and syringyl types. Fifty percent of polymeric linkages in lignin are Beta-O-4 ether linkages of phenylpropanoids. Cleavage of these linkages results in substantial depolymerization of lignin. At 250'C lignin shows little degradation, but at 300'C and above much more alteration is apparent.
From US patent H000072: Polynuclear aromatic hydrocarbons having no functional oxygen groups - like antracene, does not sustain combustion with potassium nitrate. Instead, phenolic compounds - which are aromatic compounds having functional oxygen groups, burns very fast. For example, compositions using phenolphthalein as a charcoal substitute burns in fact faster than ordinary black powder. But, phenolics which undergo hydroquinone to quinone type oxidation, are much less reactive than other phenolics notably in compositions that contain sulphur. It is assumed that sulphur turns hydroquinone/catechol moieties into some less reactive species.
From The DFRC Method for Lignin Analysis. 2. Monomers from Isolated Lignins: Relative distribution ratios of parahydroxyphenyl(P), guaiacyl(G) and syringyl(S) species of lignin propanoids depend on the wood species. Ratio for pine P=0,03 : G=1 : S=0, for aspen P=0,02 : G=1 : S=1.64, for willow P=0 : G=1 : S=1.54 and for kenaf P=0 : G=1 : S=5.08.
It is known, that pine charcoal is good for producing long lasting sparks whereas aspen or willow charcoal yields fast black powder. According to a source, the chinese use kenaf charcoal in their fast black powder. Charcoal prepared from wood with syringyl lignin, might account for fast burning rate. According to another source, 'sulphurless black powder burned faster than powder with sulphur'. This might indicate that hydroquinone to quinone type oxidation reactions take place in some charcoals. Before conclusions these claims have to be tested for proof.