Organic, anorganic acids as combustion product removers

Anorganic acids: HCl traces trapped in crystals. It would bind the potassium products.
H2SO4 - can not be added, but can be created on place by burning sulphur, sulphur needs a catalyst to reach oxidation state VI - such as V2O5.

HOOC-COOH - oxalic acid, a pretty strong one, melting point 101°C, flash point 166°C.
citric acid - melting point 153°C, decomposition at 175°C.
acetic acid - only in solutions, flash point 43°C
tartaric acid - melt point 170°C, many stereoscopic forms, dicarboxylic acid, pretty strong

Not only iron reacts in alcaline surroundings and oxygen oversupply to form strong, unstable oxidisers. Keep in mind that mixing ingredients may not yield the required result, any catalysts need to be in the right place in the right time in any reaction to work the best. Simple mixing might not suffice.

"A green substance, potassium manganate, is obtained after about 10 minutes when melting manganese(IV) oxide with an alkaline salt and adding oxidizing agents like saltpeter (potassium nitrate KNO3) or potassium perchlorate (KClO4). Potassium manganate (K2MnO4) can be purified by vacuum distilling with a metal "finish" to give dark green crystals (rhombic prisms). Potassium manganate is only soluble in alkali; in non-alkali conditions it will disproportionate into potassium permanganate (KMnO4-) and manganese(IV) oxide (MnO2)."


What comes to my mind is to wet the iron oxide with KMnO4 so that it will be coated with atomic-sized MnO2 after decomposition. We can do something similar with KNO3, pour KMnO4 solution into it, mix well and dry it afterwards, pulverise after drying.
This is the ordinary procedure for preparations of many catalysts. (followed by activation, which I will not discuss here)

Common iron oxide powders colors&compositions

Red Iron Oxides:

FEPREN TP: α-Fe2O3 (fine powder, heat resistance up to 800 ºC)
FEPREN TD: α-Fe2O3 (very fine powder, heat resistance up to 800 ºC)

Brown Iron Oxides:

FEPREN SHD: combination of α-Fe2O3 and Fe3O4 (heat resistance approx. 120 ºC)
FEPREN HM: combination of α-Fe2O3 and MnO2 (heat resistant is up to 400 ºC)

Yellow Iron Pigment:

FEPREN Y-710: FeO(OH) (heat resistance approx. 150 ºC)

I think the best is TD-202, then TP-303.

Black Pigments:

FEPREN B: FeO . Fe2O3 (heat resistance is approx. 110 ºC.)
FEPREN BP: Fe3O4 and MnO2 (heat resistant is up to 400 ºC)

Anticorrosive Red Pigment:

JACOR Fe-1: α-Fe2O3 and Zn3(PO4)2
EDIT3: This brown opwder has surprisingly similar color to the one that Nakka used in his burnrate improver experiments. A very similar coloring indeed. Zn3(PO4)2 absorbs water up to the Zn3(PO4)2 . 4(H2O), causing crystal growth. This water may be released by heating, may bause carries substance foaming too.

SOURCE here.
their website

IMPORTANT EDIT:

Dispersibility: it is measured by several methods, but it always means something about how much work is required to disperse the bigger aglomerates of powder particles into smaller ones or into the base carrying material. Why is this important: the powder particles are of size about 0.4 micrometer, but if you try to mix the powder into oil, water or other powders, you will see that many of the small 0.4micron particles are holding together in bigger lumps.
Dispersibility may be given in scale 0-10 given the relative anount of power required to completely disperse particles, or using other test, like ISO 1524... which seems to describe how fine the agglomerates will be after some stirring time.

The conclusion is: even if we have a suitable powder, we need to apply it the most efficient way into the solid fuel.

EDIT2: Magnetite - Fe3O4: The Curie temperature of magnetite is about 580°C. Magnetite is the most magnetic of all the naturally occurring minerals on Earth, - - - question is whether 5% of magnetite could improve burnrate under high pressures so much. The moving plasma gas exiting the fuel causes electric current. Thus magnetic field could move, rotate or attract the magnetite in the molten Sugar/KN mix towards the burn zone. Note to self: examine burnrate with coil over the engine.

Ceric oxide, iron oxide reaction mechanisms

I will make this short:

Ceric oxide is an oxygen conductor. The same as Platinum or Palladium is for hydrogen conductance, the same is ceric oxide for oxygen. You can deplete oxygen on one side of the crystal and supply it on the other. The crystals of ceric oxide during reactions can have precise composition of CeO2 to CeO1.5 - making it effectively Ce2O3 - but here we talk about the whole range, not a single oxide. This is extremely useful when using the nanometric powder which consist of interconnected crystals of basic 4nm size which form a flake of about 3-7 micrometers. This flake has very high surface area. When dispersed in diesel fuel for example which gets injected in tiny droplets with this snowflake inside, as the fuel evaporates the rest still hangs on the CeO2 skeleton. This skeleton has a very high surface area and can release oxygen and also receive oxygen, especially from nitrogen oxides, like NO and NO2.

Now iron - Fe - reacts with KNO3 at red heat temperatures to form potassium ferrate (very strong oxidiser), the ironic oxide Fe2O3 can be ignited with KOH (burns with flame?) to yield K2FeO4, or similar reaction with a mix of KOH and KNO3 (Fe2O3 + KOH + KNO3 —> K2FeO4 + KNO2 + H2O).
I saw somewhere a method how to react it with K₂CO₃ - which is one of the reaction products from sugar-KN burning as seen in Richard's page here.

As for the similar oxidiser MnO2:
"Fusion of MnO2 + KOH + KNO3 --> dark green managanates K2MnO4"

So, everything is possible.

Only the CeO2 reacts in similar way only with strong HNO3 to form a complex oxidiser CAN (NH4)2Ce(NO3)6 - ceric ammonium nitrate. I may try this with the AN fertiliser (as I have nothing of any purity right now :( whether it does make any difference)

In general: oxidants and oxidant precursors should be mixed and prepared together (KN+oxides) and oxygen transfer improver mixed with the fuel (sugar+CeO2).
When possible also calcinated or sintered together and pulverised after (as any normal catalyst preparation)

EDIT: The last thing I forgot to mention is the water content in the oxides. In case of the brown iron oxide, there might be the effect of accelerated foam production at high pressures perharps, or it really may be related to powder form. James Yawn uses 1-2% red iron oxed, bought al local pharmacy to increase the burn rate at atmospheric pressure about twice. In experiments made by Richard Nakka, only brown iron oxide was strong accelerant and only in case the pressure was much elevated. So, what is the ultimate accelerant? Water content? Oxide solubility in KNO3? Surface area per gram of powder? Absorbtion of the IR spectrum? All together?

The food grade Fe2O3 bought in pharmacy is likely going to be of high purity, very fine powder with no large particles, because it is used for coloring pills, gels, medications. The paint grade Fe2O3 had less accelerating properties, its purpose is to be mixed with oil for painting.

When my tools arrive:
Fe2O3 - Fepren TP-303 - not the best option, but this will be available
CeO2 - polishing grade thoriumless, high purity
KMnO4

mix1:(Fe2O3), mix2:(Fe2O3+KMnO4+CeO2)grinded together, mix3:(mix2 sintered in oxy flame, grinded afterwards)

Calcium carbide as rocket fuel?

Industrial grade calcium carbide (calcium acetylide) only contains about 80% of it. Not much, but...

Here comes the idea: CaC2 + 2(H2O) -> C2H2 + Ca(OH)2
CaC2 - 64.1g/mol, NH4NO3 - 80.04g/mol
NH4NO3 -> N2O + 2(H2O)

N2O and C2H2 is used in a safe flame for analytical spectrography, because it burns at 2300°C and has no tendency to explode, detonate, etc. (unlike etin mixture with oxygen that is.)

So I think mixtures with as much as 33% (molar %) CaC2 with AN are possible. I don't know IF the carbide will survive the 200°C of the slightly decomposing fertiliser or what will happen, what will be the mechanical properties... but I surely like this idea very much! The CaC2 itself melts only at 2300°C or so, so it will be a solid for all our considerations.


With 28.6% by weight carbide, 71.4% AN the mix would make: (only literally, not in reality)
CaC2 + 2(NH4NO3) -> 2CO + 2N2 + H2 + Ca(OH)2 . 2(H2O) + lots_of_heat

With molar mixing 1:3 the carbide is 21%, with mixing 1:4 it is 16.68%, with 1:5 13.8% carbide in AN.
The 1:5 molar mix: (13.8% CaC2)
CaC2 + 5(NH4NO3) -> 2(CO2) + Ca(OH)2 + 5(N2) + 9(H2O) + heat

so, anywhere between the 13.8% to the 28.6% would be reasonable for initial tests.

Cellulose thermal stability, decomposition

Finally found the info no wikipaedia has.

Temperatures where thermal degradation starts:
Hemicellulose - 170°C-240°C
Cellulose 250°C-350°C
Lignine 300°C-400°C

This is surprising to me, since the lignine fibres are the first to decompose under sunshine. Newspaper have high lignine content.

Why do I bring this? Well, microcellulose is available in several grades of quality. Both in fibre sizes and in chemical type. Next, cellulose is also a sugar, a carbohydrate, so you can make very similar rocket fuel as with other, simpler sugars, like dextrose and saccharose for example. This time you are not going to melt the sugar, but the oxidiser, AN for example. The microcellulose is used for making epoxy slurries that do not flow. So, I may try it one day mixing in molten AN fertiliser... one day when I will gave any good electric melter. The link to the data source is HERE. It is about "softwood thermal degradation".

Fertiliser grade AN

Modern AN fertiliser with 27%N is made by dissolving a certain amount of dolomite and then neutralising the whole mass. Finnish patent says this will yield you totally stable AN, which it is, but as I have only 27%N AN grade - that is about 27/35=77% AN content only, the rest is dolomite. The positive point is that there is no sand, there are no crude particles.
When melted, the fertiliser is stable, clay-like substance, that behaves similar to molten clay.

First: what I did was to mix little 6-micron SiC powder, more ceric oxide and the fertiliser granules. The resulting powder was finer that I got usually, and I was able without much effort to grind it few times again. (note the resulting mix may contain only 62-70%AN only :( ) I took a sample and mixed with PS glue. The PS glue was obtained by dissolving foam polystyrene in a bit of solvent. I made it syrup thick. Added some powder and mixed (approx 80% powder, 20% PS glue?). The result was something with the look and feel of modelling clay. Even after drying it is not completely hard, you can do marks with nails.

Note this composition is useless as a rocket fuel, but when Mg powder added it may be a good candle.

Burn test:
What did burn were the isolated islands of AN (bubble and boil), but the thermal isolation caused by very high inert material loading of about 25-40% did not allow flame to heat the mass. The ceric oxide does not dissolve in molten AN (so it looks), unlike the ferric oxide which does dissolve in molten KNO3.