Activated carbon is a kind of microcrystalline carbon material with black appearance, developed internal pore structure, large surface area and strong adsorption capacity. It is a commonly used adsorbent, catalyst or catalyst carrier, widely used in almost all sectors of the national economy and people's daily life. Classification of Activated Carbon - There are not less than 1000 kinds of activated carbon due to different sources of raw materials, manufacturing methods, appearance and application occasions.
Firstly, according to the source of raw materials, it can be divided into wood activated carbon (such as coconut shell activated carbon, apricot shell activated carbon, wood powder activated carbon, etc.), mineral activated carbon (activated carbon made from various coal and petroleum and their processing products), and activated carbon made from other raw materials (such as activated carbon made from waste rubber, waste plastics, etc.).
Secondly, according to the manufacturing method, it can be divided into chemical activated carbon (chemical carbon) and physical activated carbon and chemical-physical or physical-chemical activated carbon.
Chemical Activated Carbon is a method of preparing activated carbon by mixing carbon-containing raw materials with some chemicals and heat treatment. Activated carbon produced by chemical method is also called chemical activated carbon or chemical activated carbon.
Activators include zinc chloride, calcium chloride, potassium carbonate, phosphoric acid, potassium dihydrogen phosphate, potassium sulfide, sulfuric acid, potassium hydroxide, sodium hydroxide, boric acid, etc. In a word, many acids, bases and salts can be used as activators, mainly considering the properties and economy of activated carbon. What kind of activator is used?
Generally speaking, the secondary micropore and mesopore (i.e. pore diameter or pore width greater than 1.5 nanometer) in the pore of chemical carbon are more developed, which are mainly used in the gas (steam) adsorption occasions of liquid phase adsorption refining and solvent recovery.
Activated carbon manufactured by chemical method should attach great importance to environmental protection and the influence of trace elements brought in by non-raw materials.
Physical Activated Carbon (ACC) is a method that uses carbon as raw material, steam, carbon dioxide, air (mainly oxygen) or their mixture (flue gas) as the activation medium, and activates it at high temperature (600-1000 C) to produce ACC, which is called physical method. Activated carbon produced by physical method is called physical activated carbon, also known as physical carbon.
Generally speaking, the micropore of physical carbon (pore diameter or pore width less than 1.5 nanometer) is developed, which is mainly used in gas phase adsorption or small molecule liquid phase adsorption.
Chemistry-Physical or Physical-Chemical Activated Carbon
While understanding chemical carbon and physical carbon, we should also mention chemical-physical or physical-chemical activated carbon. The pore structure of activated carbon can be controlled by using different raw materials and different combinations of chemical and physical methods, and many activated carbon with different properties can be prepared. This chemical-physical method or physical-chemical method is a method of producing activated carbon which has attracted much attention of activated carbon workers all over the world for many years and for a long time to come.
Thirdly, according to the appearance and shape
Powdered Activated Carbon: Activated Carbon with a particle size of less than 0.175mm or over 90% passing through 80 target quasi-sieves is commonly called Powdered Activated Carbon or Powdered Carbon. Powdered carbon has the advantages of fast adsorption speed and sufficient adsorption capacity, but it needs special separation methods. With the progress of separation technology and the emergence of some application requirements, the particle size of powdered carbon tends to be finer and finer. In some cases, it has reached the micron or even nanometer level.
Granular activated carbon: Activated carbon with particle size greater than 0.175mm is usually called granular activated carbon.
Granular activated carbon can be divided into the following categories——
Activated carbon with amorphous granules: Activated carbon with amorphous granules is generally made from granular raw materials by carbonization, activation, and then crushing and sieving to the required granularity. It can also be made by adding appropriate binder to powdered activated carbon and processing it appropriately.
Cylindrical Activated Carbon: Cylindrical Activated Carbon, also known as Cylindrical Carbon, is generally made from powdered raw materials and binders through mixing, extrusion, carbonization, activation and other processes. It can also be extruded with powdered activated carbon and binder. Columnar carbon can be divided into solid and hollow carbon. Hollow columnar carbon is one or more artificial holes in columnar carbon.
Spherical Activated Carbon: Spherical Activated Carbon is a spherical activated carbon. Its preparation method is similar to that of columnar activated carbon, but it has a spherical process. It can also be made from liquid carbon containing raw materials by spray granulation, oxidation, carbonization and activation, and can also be processed by powdered activated carbon and binders. Spherical activated carbon can also be divided into solid and hollow spherical activated carbon.
Other shapes of activated carbon: In addition to powdered activated carbon and granular activated carbon, there are other shapes, such as activated carbon fiber, activated carbon fiber blanket, activated carbon cloth, honeycomb activated carbon, activated carbon board and so on.
Secondly, according to the application occasions: Activated carbon has been widely used in almost all sectors of the national economy and people's daily life. Because of this, it is very difficult to classify activated carbon according to its application occasions. The problem is that the same activated carbon can be used in many occasions, and in some occasions it can be used in many activities. Carbon achieves the same purpose. People often get the knowledge of activated carbon by application, so activated carbon is often used as a customized fuzzy classification method of activated carbon. Such as sugar activated carbon, injection activated carbon, monosodium glutamate activated carbon, water purification activated carbon and so on.
Performance Index of Activated Carbon
The performance indicators of activated carbon products can be divided into physical performance indicators, chemical performance indicators and adsorption performance indicators. Three performance indicators for activity
