combustion

Rapid oxidation of a fuel releasing heat and light. The chemical reaction that powered civilization from the first campfire to the rocket engine.

chemistry

fuel + O2 → CO2 + H2O + energy. Exothermic. Activation energy initiates the chain reaction; once started, released heat sustains it.

types

• complete combustion: sufficient oxygen, produces CO2 and H2O
• incomplete combustion: insufficient oxygen, produces CO (carbon monoxide), soot, unburned hydrocarbons
• spontaneous combustion: self-heating material reaches ignition point without external flame
• detonation: supersonic combustion wave, explosion

applications

• internal combustion engines: converting chemical energy to mechanical work via controlled explosions
• power generation: coal, natural gas, biomass burning to produce steam and drive turbines
• rocketry: oxidizer + fuel for thrust, escaping gravity
• metallurgy: smelting ores with coke

thermodynamics

Governed by Gibbs free energy. Enthalpy of combustion measures energy released per mole of fuel. Efficiency bounded by Carnot cycle.

connections

The rapid counterpart of fermentation (slow biological oxidation). Depends on oxidation as the core electron-transfer mechanism. Products include CO2 used in photosynthesis.