Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
Ambivalent? Are you sure?

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.



Rocket soap

Less oxidized carbon = more oomph?
  [vote for,

Rocket candy - very interesting. I have linked up the excellent video by the King of Random. 8th promised to email me what the purpose of the iron oxide was in the rocket candy but nothing yet - you get another chance, 8th.

My understanding is that rocket candy combines an oxidizable carbon source (sugar) with an oxidizer (KNO3). Oxidization produces thrust. I presume that the polymeric nature of the sugar slows the reaction so you get thrust as opposed to an explosion like with powered charcoal and KNO3 (gunpowder).

But sugar already is largely oxidized. Why not use less oxidized carbon? Fats like lard might get runny when the thing heats up and then unoxidized liquified fuel will get blasted out. Wasteful. You could use all-trans fats but thouse might be hard to come by.

Soap has almost as much unoxidized carbon as fat (or alkane) but I here assert will melt less readily - because of ionic attractions? I propose that more powerful backyard rocket fuel could be made with soap. I would use Ivory flakes and mix up the fuel exactly as the King does in the video (together with some rust if 8th is persuasive). My hypothesis is that this will provide more energy per weight than rocket candy.

bungston, Feb 19 2014

Rokcet Candy http://www.youtube....watch?v=yUYxk-y-tU8
Looks like they have put some sort of safety on this video so no viewing from work. [bungston, Feb 19 2014]


       I think you'll find the iron oxide is required in minute quantities, and is used as a catalyst for the decomposoition of the KNO3. It's very very common to have small percentages of metal oxides, or organometals in rocket fuel mixes for this reason - they catalyse decomposition of the oxidiser.   

       The difference between solid rocket fuels, and solid explosives, is at times purely in the name. Watch yourself.
Custardguts, Feb 19 2014

       It's a combustion promoter. With propellants and deflagrants, the combustion front is propagated by hot particles and thermal conduction; the rate of propagation being intentionally subsonic.   

       At the temperatures involved, iron oxides are relatively volatile ; iron has the unique property that its oxide has a lower melting point than the parent metal, this being the fact that makes welding it comparatively easy compared to most other metals.   

       Its role is not truly catalytic, as it does undergo reduction and oxidation reactions. A true catalyst is unchanged by the process in which it participates.
8th of 7, Feb 19 2014

       Agreed, but it's normally referred to as a catalyst.   

       Then again, I'm fairly sure that it comes out the exhaust as Iron oxide, so it really probably can be referred to as a catalyst.   

       Am I getting the role of FeO(x) confused with organometallics in rocket fuels? I had always beleived (because I read it) that organometallics promote the liberation of oxygen in the oxidiser, whatever that might be. I had always presumed that the Iron Oxide did the same thing.
Custardguts, Feb 20 2014


back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle