Activated carbon is a kind of black powder, granular or pill-shaped, amorphous and porous carbon. Its main component is carbon, but also contains a small amount of oxygen, hydrogen, sulfur, nitrogen, chlorine. Also it has the fine structure of graphite, but the grain size is smaller, and layer upon layer with the irregular accumulation. It is with a large surface area (500 ~ 1000 square meters / g), and has a strong absorption and can absorb gas, liquid or colloidal solids on its surface. The quality of absorbed gases or liquids can be close to the quality of activated carbon. Its adsorption has selectivity, non-polar substances are more easily absorbed than the polar substances. In the same series of substances, material with the higher boiling point will be more easily absorbed. The greater the pressure , the lower the temperature , the greater the concentration, the greater the adsorption capacity. On the contrary, decompression, and temperature increasing is benefit for gas desorption.
Activated carbon is commonly used in gas absorption, separation, purification; solvent recovery; sugar, oil, glycerol, drugs decolorant; drinking water and refrigerator deodorant; canisters agent in anti-virus mask. It can also be used as catalyst or carrier of metal salts catalyst. Early materials of activated carbon are timber, hard fruit shell or animal bones, and later coal is mainly used.
Production methods of activated carbon with dry distillation and activation are: ¢Ù steam, gas activation method. It takes the advantage of water vapor or carbon dioxide to activate carbon at 850 ~ 900 ¡æ . ¢Ú chemical activation method. It takes the advantage of gas released by activator, or activator to impregnate materials under high-temperature.
