Mobile ATEX activated carbon filter for VOC treatment
The treatment of volatile organic compounds (VOCs), vapors, odors and solvents in industry is a major public health issue. It is important to treat them to improve air quality in industrial workshops and reduce employee exposure to these pollutants. Among the technologies available, activated carbon filters stand out for their efficiency, ease of use, relatively low cost and versatility.
Activated carbon, also known as activated carbon, is a material widely used in industry for the treatment of various gaseous pollutants. Thanks to its exceptional adsorption properties, activated carbon can effectively trap many volatile organic compounds (VOCs ) and other pollutants in the air.
Activated carbon is used here more generally to refer to adsorbents and mixtures of absorbents that enable treatment by adsorption (trapping) and physico-chemical treatment (degradation).adsorption defines the property of activated carbon and certain materials (adsorbents) to bind organic molecules extracted from the air to their surface.
BENEFITS
- Easy to maintain
- Easy to use
- Simple replacement of the activated carbon cartridge
- Mobile and space-saving
special features
- Innovative design
- Several assembly options
- Main filter with activated carbon pellets for effective odor elimination
Characteristics
- Efficiently treats odors, solvents, VOCs and other gaseous pollutants
- 18.5 kg activated carbon cartridge
- Flow rate of 4,500 m3/h
How does trapping air pollutants with activated carbon work?
As polluted air flows through a layer of activated carbon, the organic pollutant in the air binds to the surface of the adsorbent material and is captured. The adsorption capacity of the adsorbent depends on :
- of the developed or specific surface area of the material. Industrial adsorbents are highly porous and develop very large specific surface areas of the order of 600 to 1,500 m²/g. On average, 10g of activated carbon has the surface area of a soccer pitch!
- the concentration of the organic pollutant. An equilibrium is established between the mass of pollutant adsorbed per unit mass of adsorbent. This can be expressed as Freundlich’s law. You can find the adoption ratios (pollutant mass / adsorbent mass) in the document
There are different types of activated carbon filters for treating the VOCs generated in industry. The main ones include filters containing granules or powder, or carbon-impregnated materials. Charcoal-impregnated filters have only a small amount of charcoal and saturate very quickly on contact with pollutants. These carbon-impregnated materials are not suitable for most industrial applications.
The advantages of activated carbon filters lie in their ability to effectively adsorb VOCs, thus reducing harmful emissions into the atmosphere. However, their use can have drawbacks, such as the need for regular replacement of saturated coal and the associated costs of new coal and disposal of used coal. If the concentration of pollutants to be treated is too high, the activated carbon charge will quickly become saturated. This means you’ll need to replace the activated carbon frequently, or have a large load of carbon on hand to last between carbon replacements. The frequency of coal replacement can be calculated as follows:
T = (1000 x Ch x K / (C x Q) :
- C = Pollutant concentration in mg/m3
- Q = Air flow to be treated in m3/h
- Ch = coal load in kg.
- K = Absorption constant in kg of pollutant per kg of adsorbent expressed in % (see list)
- T = time in h between two replacements in operating hours
It is virtually impossible to automatically measure carbon saturation unless the pollutant is unique and recurrent. Nor is there any easily measurable physical quantity that can be used to determine the degree of saturation of a coal. The increase in adsorbent weight is difficult to measure. The “return of the smell” often remains the indicator of coal saturation. This is why most activated carbon filters are equipped with an hour counter, so that the carbon is replaced after a known or theoretically calculated number of hours, according to the formula above.
When selecting an activated carbon filter, several parameters need to be taken into account, including the nature of the VOCs, or gaseous pollutants to be treated, the air flow rate, operating temperature and pressure. As a general rule, carbon treatment is used below 50°C. The higher the temperature, the lower the adsorbent’s absorption capacity.
In addition to concentration, the efficiency and service life of activated carbon filters is influenced by a number of factors, including activated carbon quality, operating conditions (temperature, pressure and humidity) and the dust contained in the flow. It’s important to filter out particles and dust from the filtered air, so that the carbon pores are not saturated with dust. High relative humidity also considerably reduces the efficiency and service life of the charcoal. If water vapor condenses, water in liquid form saturates the pores of the coal like a pollutant.
Innovative approaches are emerging in the field of industrial VOC treatment, such as the use of catalysts or nano-composite materials to improve the efficiency and durability of activated carbon filters. We also deploy adsorbents whose color changes according to the degree of saturation.
The contact time between the pollutant and the carbon is crucial. To achieve this, we favour the lowest possible flow velocities through the carbon and, of course, the highest possible activated carbon loads in relation to the flow to be treated. Filter geometry is very important to ensure long contact times. Activated carbon in cartridges offers better contact time than in beds.
To increase treatment efficiency, chemically “doped” activated carbons or mixtures of different adsorbents can be used. In particular, treatment can be targeted at families of pollutants such as :
- H2S with our specific adsorbent OBCKV-SULFREE HE
- Acid vapors, Thiols, HCI, acetic acid, formic acid with our adsorbent OBCKV-ACID FREE HE
- Formaldehyde, Aldehyde, Nitrogen dioxide NOx, Gases, H2S, HCN, Mercaptans, oxidizing gases, SO2 with our absorbent OBCKO-PURPLE
- OBCKV-CL2 Specifically for CL2, Chlorine
- OBCKV-HG for Mercury
It is also possible to combine several successive filtration stages to increase contact time and treatment selectivity.
Changing the activated carbon cartridge
Simplicity and efficiency
What to do with saturated coal at the end of its useful life.
In some cases, activated carbon can be recycled. Regeneration methods include thermal desorption and steam. These techniques restore theefficiency of the activated carbon, thereby reducing replacement costs. When coals cannot be regenerated, they can be recovered thermally, as they have a high calorific value. OberA offers take-back and recycling solutions for your used coals.
When to use activated carbon filters.
Here are a few guides to help you understand the criteria for selecting an activated carbon treatment solution.
- When VOCs, vapors, solvents or odors are present. The pollutant must be treatable with activated carbon. To be sure, refer to our list of pollutants.
- Low pollutant concentrations: activated carbon is well suited to low concentrations. As concentrations increase, oxidation processes (thermal oxidation, catalytic oxidation) make more sense. In fact, when the concentration is high, it can be interesting to “burn” it; thermal oxidation makes sense when the concentration is high enough for combustion to be auto-thermal. If the concentration is insufficient, the organic pollutant must be concentrated or gas added to burn it off.
- Low flow: if the flow to be treated is low, activated carbon treatment makes sense, as the equipment is generally less expensive than other technologies such as thermal oxidation, biofilters, etc.
Which industrial applications can be treated with activated carbon?
VOCs are a class of organic chemical compounds that evaporate easily at room temperature and can have harmful effects on human health and the environment. Among the VOCs most commonly treated with activated carbon are styrene, benzene, toluene, ethylbenzene and xylene (BTEX), as well as other aromatic and aliphatic hydrocarbons, formaldehydes. In addition to VOCs, activated carbon is also effective in removing other gaseous pollutants such as halogenated organic compounds (HOCs), toxic gases like carbon monoxide (CO), odorous compounds, solvent vapors, sulfur compounds, nitrogen compounds and many other harmful substances.
These pollutants are emitted by a multitude of industrial sources such as :
- combustion or heating processes leading to thermal degradation of hydrocarbon-based compounds (plastic injection, laser cutting, 3D printing, engraving, etc.)
- adhesives and sealants used in industry
- formulation and use of resins, hardeners…
- cleaning, degreasing and painting solvents, etc.
- chemical formulations (weighing, pouring, filling, etc.)
- odours and VOCs generated by the degradation of organic matter
Pollutants
Industry
Suitable for all types of industry, contact us to discuss your requirements.
The features
Appareil | MOBFAN 4500 | |
---|---|---|
Débit d'air | m3/h | 4500 |
ATEX | Poussière Gaz | Zone 22 Zone 2 |
Pression max | Pa | 2000 |
Masse de charbon actif | kg | 18.5 |