Fire and Pyrolysis Terminologies

Study Notes

Fire is the rapid chemical reaction between fuel and an oxidizer, releasing energy in the form of heat and light.
Pyrolysis is the chemical decomposition of matter through heat, which can cause a change from a solid state to vapor state.
Combustion is a self-sustaining chemical reaction producing energy or products that cause more reactions of the same kind.

Fire Triangle (Glowing Mode): • Oxygen • Fuel • Heat
Fire Tetrahedron (Flaming Mode): • Oxygen • Fuel • Heat • Self-sustained Chemical Reaction

Fuel: anything that will burn when heated with sufficient oxygen, comes in three forms: solid, liquid, or gas. • Solid: molecules are closely packed together • Liquid: molecules are loosely packed • Gas: molecules are free to move

Types of Flammable solids: • Pyrolyzable solid fuels: include many ordinary accepted combustibles (e.g. wood, paper) • Non-pyrolyzable solid fuels: solid fuels that are difficult to ignite (e.g. charcoal)
Examples of solid fuels: • Biomass: replaceable organic matters like wood, garbage, and animal manure • Fabrics and Textiles: fibers are very fine thin strands or thread-like objects • Plastics: Cellulose Nitrate is a chemical powder used in bombs, also called pyroxylin • Coal: a black, combustible, mineral solid resulting from partial decomposition of matter • Peat: partially decayed plant matter found in swamps

Liquid fuels are mainly made from Petroleum, but some synthetic liquids are also produced
2 General Groups of Liquid Fuels: • Flammable liquids: have a flash point of 37.8 °C (100°F) and a vapor pressure not exceeding 40 psia (2068.6 um) at 37.8 °C • Combustible Liquids: have flash points at or above 37.8 °C (100°F)

Gaseous fuels: molecules are in rapid movement and random motion, have no definite shape or volume, and assume the shape and volume of their container
Examples of gas fuels: • Natural Gas: consists chiefly of methane, a colorless and odorless gas • Acetylene, propane, and butanes • Natural Gas is usually mixed with compounds of foul-smelling elements like sulfur to detect gas leaks