A charcoal canister captures potentially harmful emissions from a car’s engine and prevents them from being released into the atmosphere. A charcoal canister, also known as a vapor canister, is the part of a car’s evaporation control system that is designed to prevent the release of volatile organic compounds that escape from a car’s fuel system and engine.
Charcoal pellets in the canister absorb the harmful fumes emanating from the car’s fuel system and store them until the engine burns them when it is running.
The canister is normally black and is placed in one of the far corners of the engine compartment. However, some car manufacturers mount the canister closer to the fuel tank so as to maximize efficiency.
Evaporation control systems in cars were introduced in the 1960’s and their initial purpose was to absorb crankcase fumes and prevent them from venting out into the atmosphere via road draft tubes that were in use at the time. The emitted vapors were visible and were thought to be the main cause of smog.
By absorbing the harmful fumes back into a car’s fuel system, a car’s evaporation control system not only helps make for a cleaner engine but also helps to keep the environment safer for habitation.