Auto-ignition temperature

Auto-ignition temperature or self-ignition temperature is the minimum temperature at which a material or substance spontaneously ignites in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion.

Overview

The auto-ignition temperature of a substance is a critical factor in many industrial processes and is particularly important in the context of fire safety. It is a key parameter in the study of thermodynamics and kinetics, and it is used in the design of safety systems for processes involving flammable substances.

Factors Influencing Auto-Ignition Temperature

The auto-ignition temperature of a substance is influenced by several factors, including the pressure, the concentration of the substance in the air, and the presence of catalysts. For example, the auto-ignition temperature of hydrogen is lower in the presence of oxygen than in pure air.

Measurement

The auto-ignition temperature of a substance is typically measured using a bomb calorimeter. The substance is placed in the calorimeter, which is then heated until the substance ignites. The temperature at which this occurs is recorded as the auto-ignition temperature.

Applications

Knowledge of the auto-ignition temperature of a substance is used in a variety of applications. For example, in the design of internal combustion engines, the auto-ignition temperature of the fuel is a critical parameter. In the field of fire safety, knowledge of the auto-ignition temperature of materials is used to design fire prevention and suppression systems.

See Also

• Flash point
• Fire point
• Flammability limit
• Combustion