Charcoal is a kind of fuel. It is a dark brown or black porous solid fuel that remains after wood or wood-based raw materials are incompletely burned or thermally decomposed in an oxygen-free environment. Activated carbon is amorphous carbon that has undergone activation treatment. It comes in powder, granular or pellet form and has strong adsorption capacity. The activation treatment removes various oils and impurities on the surface of amorphous carbon, increasing the number of pores, enlarging the surface area and enhancing surface activity, thus enabling it to adsorb many gases, liquids or certain solutes in solutions. Charcoal and activated carbon have significant differences in raw materials, preparation methods, structural characteristics and application fields.
Firstly, the raw material for charcoal is mainly wood, usually hard for example willow, oak etc. There are various type of raw materials for producing activated carbon, such as wood, coal, coconut shells, bamboo and other carbon-containing substances.
Secondly, regarding the preparation methods, charcoal only requires wood to be heated in an oxygen-free environment to remove moisture and organic substances, in the mean time, retaining the carbon structure. During this process, only carbonization is involved, without activation. However, activated carbon involves both carbonization and activation process. The treatment methods include two types: physical activation and chemical activation.
Thirdly, regarding the structure and adsorption performance, in terms of pore structure,activated carbon has diverse pore sizes and is highly porous, while charcoal has fewer pores. In terms of adsorption capability, charcoal, which haven't had activation process, its adsorption properties come from residual micropores and has a relatively weak adsorption capacity. While Activated carbon can adsorb organic matter,odors, etc., and has a strong adsorption capability. In terms of combustion performance, charcoal has a long burning time and excellent heat preservation performance, while activated carbon is not used as a fuel and has a weak combustion performance. Finally, in terms of their application, charcoal can be used as fuel and heat source in cooking scenarios such as barbecues, steaming; Activated carbon is mainly used for environmental purification with adsorption as its core role. It is used in water treatment to remove impurities, odors, etc., and in gas purification to remove formaldehyde and deodorize.
In a word, although both charcoal and activated carbon are carbon-containing substances, the differences in their manufacturing processes results in totally different properties and uses, and they should not be confused.