Activated carbon odour control is a method of removing odorous gases, volatile compounds and airborne pollutants from contaminated industrial air before it is discharged into the atmosphere. It is widely used for wastewater treatment, waste processing, anaerobic digestion, food production and manufacturing applications where reliable control of process emissions is required.
The process works by passing contaminated air through specially selected activated carbon. Activated carbon has an extremely porous internal structure, giving it a large surface area onto which gaseous pollutants can attach through a process known as adsorption.
Unlike absorption, where a substance is taken into another material, adsorption causes contaminant molecules to collect on the surface of the carbon. The treated air can then continue through the system before being safely discharged.
Exeon’s hi-flo™ activated carbon system uses deep-bed activated carbon adsorption to provide industrial odour and emission control across applications with both significant airflow volumes and demanding contaminant loads.
What Pollutants Can Activated Carbon Treat?
Activated carbon can remove a wide range of gaseous contaminants, although the correct carbon media must be selected for the pollutants present.
Typical contaminants include:
- Hydrogen sulphide (H₂S)
- Ammonia (NH₃)
- Mercaptans
- Volatile organic compounds (VOCs)
- Solvent and organic vapours
- Other industrial odour compounds
Different types of activated carbon have different adsorption characteristics. Standard carbon may perform well against certain VOCs and general odours, while chemically treated or impregnated carbon can be selected for compounds such as hydrogen sulphide or ammonia.
Exeon provides further information on the principles behind activated carbon air treatment and selects the carbon media according to the contaminant profile and treatment requirements of each application.
Where Is Activated Carbon Odour Control Used?
Activated carbon systems are used wherever extracted process air contains odours or gaseous pollutants that need to be reduced before discharge.
Common applications include sewage and wastewater treatment plants, waste transfer stations, refuse-derived fuel facilities, anaerobic digestion plants, composting facilities and industrial production environments.
For example, Exeon installed a hi-flo™ odour control system at an anaerobic digestion facility where a twin dual-bed carbon system reduced measured odour levels from approximately 6,000 ouE/m³ at the inlet to around 200 ouE/m³ at the outlet.
Activated carbon is one of several industrial odour and emission control technologies available, alongside biological filtration and wet scrubbing.
How Does the hi-flo™ System Treat Contaminated Air?
Contaminated air is first extracted from the building, vessel or process area and directed towards the hi-flo™ system. Where dust or particulate matter is present, pre-filtration can be installed to protect the carbon media and maximise its working life.
Air is then distributed through a deep bed of activated carbon. Correct airflow distribution and contact time allow contaminants to adsorb onto the carbon before the treated air is extracted and discharged through the system’s exhaust.
The hi-flo™ range is modular and can be configured for large industrial airflow requirements, with multiple units operating in parallel where required.
For facilities dealing with persistent industrial odours or gaseous emissions, activated carbon can therefore provide a flexible and effective treatment method, either as a standalone solution or as part of a wider industrial odour and emission control system.