In recent years, concern for the health and comfort of vehicle occupants has increased dramatically. This has extended to concerns dealing with removing harmful and/or unpleasant odorous materials from air within the passenger cabin environment. Particulate filtration systems have been introduced, first in Europe, but now in the US, to remove airborne solids including soot and pollen, and auto makers are now addressing systems designed to additionally remove objectionable gases and vapors. Studies have shown that the auto cabin environment and the air surrounding the automobile contain a wide range of airborne materials. Considering this variety of materials, it is highly likely that activated carbon will be a component of any successful odor removal system.
Activated carbon materials are capable of removing a wide variety of contaminants from cabin air streams. Conventionally, activated carbon removes odorous materials by means of physical adsorption. This is particularly effective for removal of organic gases and vapors from air. In cases where the contaminants are not effectively removed by physical adsorption, chemicals may be added to activated carbon to provide capability for chemical reaction with the odorous vapor. In this way, volatile materials such as ammonia, light aldehydes and others may be effectively removed from an air stream. Finally, activated carbon may be imparted with the ability to remove gases including sulfur dioxide, hydrogen sulfide, nitrogen oxides and others by means of reactions catalyzed by the carbon itself.
This discussion will provide perspectives on activated carbons and their use in automobile cabin odor control applications. It will also discuss how activated carbon can be tailored to filter design parameters to produce an effective filter.