In short, the production of activated carbon is divided into two steps: carbonization and activation.
The preparation of activated carbon must first carbonize the raw materials
Carbonization is also called pyrolysis, which is heating the raw material under the condition of isolating air, and the temperature is generally below 600℃. Sometimes the raw materials are first dissolved in inorganic salts and then carbonized. After the activated carbon raw material is carbonized, it will separate and liberate gases such as water vapor, carbon monoxide, carbon dioxide and hydrogen; the raw material is broken down into fragments and recombined into a stable structure. These fragments may be composed of some microcrystals. Microcrystals are composed of two or more pieces of sheet-like structures with carbon atoms arranged in a hexagonal lattice. But there is no fixed crystal form for accumulation. The size of the microcrystal is related to the composition and structure of the raw material, and is affected by the carbonization temperature, and roughly increases with the increase of the carbonization temperature. After carbonization, some residual hydrocarbons are attached to the boundary atoms of the microcrystals.
Activated carbon semi-finished products are activated
Activation is to heat the carbonized material under the action of an oxidant to produce activated carbon products. When the oxidation temperature is 800-900℃, steam or carbon dioxide is generally used as the oxidant; when the oxidation temperature is below 600℃, air is generally used as the oxidant. There is only a general understanding of the role played by the activation process. During the activation process, the hydrocarbons adsorbed during carbonization are burned off, and the hydrocarbon atoms on the edges of the original voids are burned, which has the effect of expanding the pores and burning through the pores. Activation makes the activated carbon become a good porous structure, and the crystal flakes after carbonization and activation.
Activated carbon can only be produced by specialized enterprises, and the production equipment is not generally large, especially for the activated carbon used to control decoration pollution, the production process is even more complicated, and not all activated carbon can control decoration pollution, and some are used for water purification. Some are used to purify the air, and are divided into coal, wood, and nut shells in terms of material.