Activated carbon is a black powder, which is granular or pill-like amorphous carbon with many holes. The mainly composition is carbon and also a small amount of oxygen, hydrogen, sulphur, nitrogen and chlorine. It also has the fine structure as graphite, but grain is small and there are irregular stacks between layers. Activated carbon has a larger surface area (500 to 1,000 m 2 / g) and a strong absorption property and its surface can absorb gas, liquid or colloidal solid. The quality of absorbed substances, such as liquid and adsorption material, is close to the quality of activated carbon. Its absorption is selective, so non-polar material is more easily absorbed than the polar material. In the same series of materials, the materials with higher boiling point are more easily absorbed. The greater of pressure, the lower of temperature, the higher of concentration, and the greater absorption capacity. Otherwise, decompression and promotion of temperature will benefit to the absorption of gas. It is commonly used in gas adsorption, separation and purification, solvent reclaim, depigmenting agents of sugar solution, fats, glycerin and drug, deodorant of drinking water and refrigerator, disinfectant of gas masks. It also can be used as the carrier of catalyst and metal salts catalyst. ]]>