The Biochemistry of Breathing Fire

Could dragons do what no known organism has done before?

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Breathing fire wouldn’t be easy. First, a dragon’s body would need to produce and store some volatile substance. Then, it would need to eject that substance at high speeds, kind of like burping but in a more prolonged and organized manner. Finally, the dragon would need to ignite that fuel as it left its body. The dragon would also need to be internally and externally fireproof to survive its own flames. Is such a setup even possible? Let’s find out.

First, the fuel. There’s already a flammable compound that forms inside many animals: methane. Methane is produced by microbes in the intestines of many animals as they break down partially digested food. We’ve established that dragons would likely evolve air sacs to store the oxygen needed to power their muscles. Perhaps similar sacs could evolve to gather methane instead. We can determine how much methane our dragon would need to store by comparing its output to that of a flamethrower.

On a full tank of fuel, the X15 flamethrower can shoot fire up to 45 feet(14 m) for a…