Many activated carbon products are on the market today that offer the necessary properties for air filtration. Typically, a carbon with a high micropore volume is the starting point, to allow for a high capacity for contaminants at low concentrations. Activated carbon can be used in extruded, granular, and powdered forms. Extruded forms are the most common due to lower pressure drop, and powdered carbons are often immobilized onto a substrate (non-woven fabric).
When considering activated carbon for air filtration, several factors needs to be taken into account:
- Adsorbate type and concentration
- Oxidation/reaction potential for adsorbed compounds (most commonly associated with ketones)
- Air temperature, and
- Relative humidity of the air stream (RH levels in excess of 50% can lead to excessive moisture adsorption onto the carbon, impacting contaminant removal)
