Activated Carbon

Activated carbon is a specially treated charcoal. Organic raw materials (husks, coal, wood, etc.) are heated in the absence of air to reduce non-carbon components (this process is called carbonization), and then react with gas, and the surface is Erosion, resulting in a microporous structure (this process is called activation). Since the activation process is a microscopic process, that is, the surface erosion of a large number of molecular carbides is point erosion, so the surface of activated carbon has countless fine pores. The diameter of micropores on the surface of activated carbon is mostly between 2 and 50nm. Even a small amount of activated carbon has a huge surface area. The surface area per gram of activated carbon is 500-1500m2. Almost all applications of activated carbon are based on this characteristic of activated carbon.

Activated carbon is prepared by pyrolysis and activation of carbon-containing raw materials such as wood, coal and petroleum coke. It has a developed pore structure, a large specific surface area and abundant surface chemical groups, and has a strong specific adsorption capacity. A general term for carbon materials.

It is usually powdery or granular porous amorphous carbon with strong adsorption capacity. It is made of solid carbonaceous matter (such as coal, wood, hard nut shell, fruit core, resin, etc.) under the condition of isolated air through high-temperature carbonization at 600-900 ° C, and then at 400-900 ° C with air, carbon dioxide, water vapor or The mixed gas of the three is obtained after oxidation and activation.

Carbonization volatilizes substances other than carbon, and oxidation activation can further remove residual volatile substances, generate new and expand original pores, improve micropore structure, and increase activity. Carbon activated at low temperature (400°C) is called L-charcoal, and carbon activated at high temperature (900°C) is called H-charcoal. H-char must be cooled in an inert atmosphere, otherwise it will transform into L-char. The adsorption performance of activated carbon is related to the chemical properties and concentration of the gas during oxidation and activation, the activation temperature, the degree of activation, the composition and content of inorganic substances in activated carbon, etc., and mainly depends on the nature of the activated gas and the activation temperature.

The carbon content, specific surface area, ash content and pH value of the water suspension of activated carbon all increase with the increase of activation temperature. The higher the activation temperature, the more completely the remaining volatile substances volatilize, the more developed the microporous structure, and the greater the specific surface area and adsorption activity.

The composition and content of ash in activated carbon have a great influence on the adsorption activity of carbon. The ash content is mainly composed of K2O, Na2O, CaO, MgO, Fe2O3, Al2O3, P2O5, SO3, Cl-, etc. The ash content is related to the raw materials for preparing activated carbon. Moreover, with the removal of volatiles in the carbon, the ash content in the carbon increases more.

Application field

(1) Treatment of oily sewage

(2) Treatment of dye wastewater

(3) Treatment of mercury-containing wastewater

(4) Treatment of chromium-containing wastewater

(5) Catalysis and supported catalysts

(6) Clinical medical use

(7) For supercapacitor electrodes

(8) for hydrogen storage

(9) Used for flue gas treatment

(10) Other applications