Dragons are always pinned and penned as mythical creatures, beasts of fancy fought by knights, honored by Chinese Monks, and ridden by Vikings. No one has see a dragon skeleton, though this dinosaur fossil is pretty close.
Nature has provided some clues as to possible ways a dragon might actually breathe fire.
Pyrophoric molecules burst into flame the instant they contact air.
Cave dragons with a lot of iron in their system could use iron sulfide to create their flame. Iron sulfide explodes when it mixes with oxygen.
The best part about this article is the reference to Pern ❤ ! McCaffrey describes her dragons chewing on rocks containing phosphine — a chemical made of one phosphorus atom and three hydrogen atoms. In gas form, phosphine is very flammable and explodes on contact with oxygen.
But rather than having dragon flames exploding back into their faces, dragons are depicted as projecting the flame from them like a flamethrower. Gas would need exceptional pressure to remain under control. Methane even seeps through membranes, and some gases are only liquid at low temperatures, too cold for even a cold blooded beast.
If a dragon were to shoot an aerosol spray, however, it could look like a gas, with some of the properties of a liquid. “In a fine aerosol spray, it would look like the dragon is spraying fire,” Raychelle Burks, a chemist in Texas at St. Edwards University in Austin, notes. The aerosol would spread out, she says, “and the minute it hits air — kaboom!”
Another solution is anaerobic – or without oxygen – energy production.
High energy phosphates are stored in limited quantities within muscle cells. Anaerobic glycolysis exclusively uses glucose (and glycogen) as a fuel in the absence of oxygen. Glucose just so happens to be flammable – when its particles are small enough.
So perhaps dragons would not have needed to chew rocks with phosphine after all. They just need to be super physically active for short bursts of time and spray their flammable glucose.