Treatment of air emissions: how activated carbon compares with other technologies
Across Europe, industries are seeking effective solutions to solve the problems of contaminated air emissions.
Activated carbon filtration is an efficient and adaptable solution in many situations, either on its own or in combination with other technologies.
Typical challenges in air emissions
There are two main forms of air pollution that activated carbon can treat:
- Volatile Organic Compounds (VOCs). Many are subject to regulations as they can be harmful to human health or the environment.
- Odorous compounds. These can be VOCs as well, or inorganic compounds such as H₂S and NH3. Regulations aim to make conditions more pleasant for employees or nearby residents.
Plants are subject to emission limits depending on the industry, the type of compound, its toxicity level, the region, and proximity to residential areas. Benzene, for example, which is known to be potentially carcinogenic, is strictly controlled.
Companies may choose to go lower than the legal limits, for example to improve the smell of the workplace for their employees.
Sectors and sources
Activated carbon can be used to treat compounds from different sources in a range of settings.
Polluted air emissions are problematic for various industries. This is especially the case for chemical, petrochemical and pharmaceutical companies because of their wide use of solvents or base chemicals and the presence of intermediates. Producers of plastics, polymers and composites have to deal with very similar issues. However, for composite production, one issue is observed throughout the sector: odorous styrene emissions.
Generally speaking, the manufacturing industry has to deal with VOC emissions from, for example gluing, coating, drying and cleaning of products. VOC emissions and odour control are important topics for all companies involved in waste handling or recycling. These emissions are characterized by a wide variety of components, directly related to the type and composition of waste. Although the specific issues can differ from sector to sector, we’ve listed several key sources of air emissions throughout the industry.
Production processes. VOCs and odours may be emitted at many stages, including from reactor tanks, coating lines and drying processes.
Tank storage. Products can be stored in gas or liquid form. Activated carbon filtration is most useful for liquids, such as petrol, benzene or more specialized organic chemicals. It can be used for emissions from huge storage facilities at ports, smaller tanks at industrial sites, and transportation containers. Emissions are typically discontinuous flows with high concentrations.
Production halls. If there are leaks in valves or sealants, tiny amounts of VOCs and odours can be released, creating an unpleasant working environment. This scenario typically produces low concentrations and high flow rates.
Aside from industry, other sources of VOCs and odour pollution include agriculture and transport. However, as these are not point sources, activated carbon filtration is not applicable.
In recent years, the industry has made great strides in tackling air pollution. As limits have become more stringent, companies have sought to tackle even the smallest sources of emissions.
Air emission treatment technologies
Want to know more about the technologies suitable to treat these air emission problems?
Download our e-book here in which we describe the available technologies, how they compare to each other and how they can be combine for optimum efficiency - with a focus on activated carbon filtration.
At DESOTEC’s facilities, all used carbon is analysed so the right measures can be taken for handling and removing the saturated carbon out of the mobile filters. All molecules that were adsorbed on the activated carbon at the customers’ site, are desorbed inside DESOTEC’s reactivation furnaces. These contaminants are then fully destroyed, in accordance with National and European legislation, by an incineration and neutralisation setup. The entire installation and it's emissions are under continuous on-line monitoring, which guarantees that only harmless water vapour is seen exiting the chimney.