Thanks to our unique technology of charcoal activation we produce activated birchwood charcoal which is free of any combustion products. On customer’s request we manufacture activated charcoal with specified adsorption activity and fractional composition. Our charcoal is evenly activated. All our products conform to requirements set forth in relevant GOSTs and technical specifications. The charcoals are highly homogeneous and consumer friendly, which is confirmed by multiple comments of our customers.
Activated charcoal (Carboactivatus in Latin) is coal with high adsorption capacity.
Activated charcoal is a grained or powdered porous carbon material which develops a large surface area adsorbing substances, when it comes into contact with gaseous or liquid media. Useful properties of charcoal were known to ancient Egyptians who used it in medicine back in 1500s BC. Ancient Romans also used charcoal to purify water, beer and wine. Today activated charcoal is ranked among the major filtering materials. The scope of use of charcoal has expanded drastically. In addition, activated charcoal plays an important role in environmental protection.
Activated charcoal has large adsorption surface area and, thus, is capable of removing multiple substances (hydrocarbons and their derivatives especially, while it is a bit less effective for adsorbing spirit, ammonium, water, and other polar substances). Fine-pored activated charcoal is obtained by thermal decomposition (charring without access of air) of some polymers.
Pore size varies from 1.6 nm (with specific surface area of up to 1000 m2/g) to more than 200 nm (with specific surface area of about 1 m2/g). Fine-pored activated charcoal is effective for adsorption even at low concentrations and partial vapour pressures. Large-pored activated charcoal is characterized by capillary condensation in pores.
How is activated charcoal made? First, carbon-containing raw materials are carbonized, i.e. the raw materials are burnt at high temperatures in an inert environment protected against penetration of air. However, the carbonated coal obtained in the process has poor sorption properties, since its pores and internal surface area is small. That is why the carbonized coal is then activated to gain a specific pore structure and to improve its adsorption properties.
Pore structure: There are three categories of pores of activated charcoal: micro-, meso- and macropores. Most of pores of activated charcoal are micro- and mesopores. Hence, such pores determine sorption properties of charcoal. Micropores are especially good in adsorbing small molecules, while larger organic molecules are absorbed by mesopores. Initial raw materials play a crucial role in formation of the pore structure of charcoal.
Adsorption: Molecules of pollutants to be removed are retained on the surface of activated charcoal by intermolecular van der Waals forces. Activated charcoal, therefore, removes pollutants from substances (unlike materials which just discolour substances, i.e. substances which do not remove but rather discolour molecules). Efficiency of charcoal as an adsorbent depends on its adsorption surface area. Furthermore, efficiency of charcoal may be influenced by some other factors such as size of molecules of the adsorbate, size of pores and granules of the charcoal, temperature, and pH of the solution.