Adsorption
Activated carbon
Activated carbon is one of the frequently used adsorption materials in industry. A common characteristic of these adsorbents is the amorphous structure with a high carbon content and water-repellent surface. Activated carbon exhibits by its very high porosity and specific surface area a relatively high adsorption capacity for a multiplicity of molecules. The specific adsorption capacity is dependent on the size and polarity of the molecules to be adsorbed. On industrial scale it is produced from wood, turf, coconut shells, lignite and coal by chemical or gas activation, respectively. It is commercially available in form of pellets, granulate or powder.
Special kinds of activated carbon are the carbon molecular sieves (CMS). These materials are mainly used for gas separation. For this purpose the pore diameters of the carbon structure are exactly adapted to the diameter of the molecules to be separated.
Activated carbon is used in many gas and liquid applications such as:
Chemical activated carbon based on wood and steam activated carbon based on PET and coal are frequently applied in the food and beverage industry. Thanks to their adsorption properties these kinds of activated carbon are used for the removal of coloring impurities, undesirable taste, odors and contaminating molecules with large, medium or small molecular weight. Such types of active carbon are used for the purification of the following products:
- Alcoholic beverages (beer, wine, whisky, white rum, etc.)
- Non-alcoholic beverages
- Sugar and sweeteners (cane sugar, beet sugar, xylitol, aspartame, etc.)
- Decaffeinated coffee
- Flavoring agents (yeast extract, proteins, etc.)
- Chemical and pharmaceutical products (paraffin, waxes, gelatin, pectin, insulin, antibiotics, etc.)
The typical properties of these activated carbon products are described below. C&CS #497 is an representative example for an activated carbon that is mainly used in the field of oil treatment. C&CS offers a variety of different activated carbon types, which cover all of the applications listed above. If you would like to know, what type of activated carbon is suitable for your special application, please do not hesitate to contact our experts by our contact form.
C&CS 497 Activated carbon, powder | |
|---|---|
Density [kg/m3] | 650 ± 100 |
Iodine number | min. 500 |
Durabiltiy | – |
BET surface [m2/g] | min. 1200 |
Shape | Powder |
Size [mm] | – |
In water treatment with activated carbon adsorbents unpleasant taste and odor are removed as well as harmful components like pesticides and halogenated hydrocarbons. Beside its adsorption properties activated carbon can also be used as a catalyst for the dissociation of oxidizing agents like chlorine and ozone. Thanks to these catalyst properties activated carbon is also used for dechlorination and deozonation of swimming pool water.
Different types of activated carbon are extensively used for the treatment of drinking and swimming pool water in form of powder, granulates and pellets. Furthermore, the microbiological growth on activated carbon can be prevented by means of a Silver impregnated activated carbon.
The typical properties of activated carbon products for use in the field of water treatment are described below. If you would like to know, which activated carbon product is suitable for your special application, please do not hesitate to contact our experts by our contact form.
C&CS #781 Activated carbon, Granulates | |
|---|---|
Density [kg/m3] | 500 ± 25 |
Iodine number | 1050 |
Durability | – |
BET surface [m2/g] | approx. 1100 |
Shape | Granules |
Size [mm] | 0,5 - 2,5 mm |
Since 1960 the gas purification and the industrial gas separation are performed by means of pressure swing adsorption plants (PSA). Main features of PSA plants are adsorption under high pressure and desorption under low pressure. The following adsorption agents are used in such PSA plants: Zeolite molecular sieves and /or carbon molecular sieves (activated carbon with very fine pores).
Activated carbon is used in pressure swing adsorption plants, in which the following gas separation applications are performed:
- Hydrogen from coke oven or from reformer gas
- Nitrogen fromair
- Methane from biogas
The typical properties of such activated carbon products are described in the following. As an example the activated carbon product C&CS #540 that is mainly used for the removal of oil from feed gases e.g. hydrogen is presented below. C&CS offers a variety of active carbons, which cover all of the applications mentioned above.
If you would like to know, which C&CS active carbon product suits your applications the best, do not hesitate to contact our experts by our contact form.
C&CS 540 – Pelletized activated carbon | |
|---|---|
Density [kg/m3] | 500 |
Iodine number | min. 800 |
Durability | min. 90 |
BET surface [m2/g] | 900 |
Shape | Pellets |
Size [mm] | 3 or 4 |
Activated carbon is often used in process gas and air purification, particularly in the following applications:
- Production of pure gases
- Protection against toxic gases
- Removal of oil from compressed air and other compressed gases
- Air conditioning
- Exhaust gas purification
- Removal of impurities from input gases upstream of the catalyst- or molecular sieve-beds
- Breathable air purification: Dust and respirator masks
- Protection against dangerous gases in different industrial sectors
- Removal of hydrogen sulfide from natural gas
- Removal of hydrogen sulfide from biogas (potassium iodide impregnated activated carbon)
- Control over the odor emission: wood chip drying (pinene, terpene), polymer processing (styrene, benzene, etc.), domestic applications (exhaust hood, refrigerator)
- Cigarette filter to reduce the nicotine and tar content in the smoke
The typical properties of such activated carbon products are described in the following. As representative example the activated carbon C&CS #643 mainly used for the purification of feed gas, off-gas and oilremoval from feed gas is presented below
. C&CS offers a variety of active carbons, which cover all of the applications mentioned above. If you would like to know, which C&CS activated carbon product is suitable foryour special application, please do not hesitate to contact our experts by our contact form.
C&CS 643 – Pelletized activated carbon | |
|---|---|
Densitiy [kg/m3] | 450 |
Iodine number | > 1050 |
Durability | > 95 |
BET surface [m2/g] | 1150 |
Shape | Pellets |
Size [mm] | 3 or 4 |
The recovery of solvents / organic vapours from different gas streams, including ambient air, is a necessity in a lot of industrial branches, like the chemical and printing industry as well as in the area of metal degreasing, rubber, additives, fragrances and flavoring agents. Activated carbon is able to remove these solvents / organic vapours very efficiently even with very low contents (e.g. 0.1 g solvent/m3).
Activated carbon C&CS #695 is one of our products, which can successfully be used in such applications. If you would like more information about our activated carbon products, please do not hesitate to contact us by our contact form.
C&CS 695 – Granular activated carbon | |
|---|---|
Density [kg/m3] | 500 |
Iodine number | > 1050 |
Durability | > 95 |
BET surface [m2/g] | 1100 |
Shape | Granulate |
Size [mm] | 1.7–3.3 or 2.5–4.5 |