Been thinking about different atmosphere’s for sci-fi planets and the like, and I know that (allegedly) if there was 5% more oxygen on earth, then bugs and insects would grow to be much, much larger. Apparently the higher oxygen concentration in the early years of our planet is why there was so much megafauna (smth about cyanobacteria?), but how would that affect the way things burn? Since oxygen is incredibly flammable, I would assume that more oxygen = bigger flame, but usually that’s pure oxygen.
tl;dr
How does oxygen concentration affect the way things burn?
In: Chemistry
Also, oxygen itself is not flammable. When you burn something you are creating a chemical reaction that combines the fuel, wood for example, with oxygen. The more oxygen available, the faster this can occur
Oxygen isn’t flammable.
Combustion requires fuel, energy for ignition, and an oxidiser.
For combustion, the fuel must be oxidised. That means it needs to give some of its electrons to something. Oxygen is a great oxidiser because it’s really good at *receiving* electrons. The oxygen itself does not combust – it allows the fuel to combust.
So generally speaking, as long as you have fuel, more oxygen will result in readier combustion.
If you soak cotton wool in liquid oxygen it will pretty much explode when lit. https://youtu.be/C0U4_k1iO6w
The more oxygen available the faster things will burn.
Dont think the percentage would effect the burning temp. However longer burning time would make it seem like it’s hotter when you calculate temp from convective and conductive heat transfer. I bet radiative heat transfer would remain the same.
As fore easily part, ofc yes. Oxidation of iron is burning so the more % you have, easier the burning.
Along with everything else mentioned, when there is an open flame, that flame is composed of all of the gas in the atmosphere plus the fuel. If 80% of the atmosphere is inert nitrogen, then 80% of the gas in the flame is contributing no heat and has to be heated up by the flame which cools it.
It will burn much hotter and faster. Oxygen isn’t flammable. But fire is indeed an exothermic oxidation reaction. So more oxygen would increase that chemical reaction.
Oxygen results in a readier(best term i can think of) combustion, not a hotter or easier combustion. You still need an accurate amount of fuel and energy to cause a fire.
Yes, everything burns better with more oxygen. This also includes some things spontaneously igniting or burning that normally wouldn’t – for example in pure oxygen at 1 atmosphere, steel will burn and certain oils would self-ignite even at room temperature.
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