Activated carbon
activated carbon
It is a kind of black powdery, granular or pellet-shaped amorphous porous carbon. The main component is carbon and also contains Small amounts of oxygen, hydrogen, sulfur, nitrogen, and chlorine. It also has a fine structure like graphite, but the grains are smaller and the layers are irregularly stacked. It has a large surface area (500 to 1000 m2/g) and has strong adsorption performance. It can adsorb gases, liquids or colloidal solids on its surface; for gases and liquids, the quality of the adsorbed material can be close to that of activated carbon. The quality itself. Its adsorption is selective, and non-polar substances are easier to adsorb than polar substances. In the same series of substances, substances with higher boiling points are more likely to be adsorbed. The greater the pressure, the lower the temperature, the greater the concentration, and the greater the adsorption capacity. On the contrary, reducing pressure and raising temperature are beneficial to gas desorption. It is often used for gas adsorption, separation and purification, solvent recovery, decolorizing agent for sugar liquid, grease, glycerin and drugs, deodorant for drinking water and refrigerators, poison filter in gas masks, and can also be used as a catalyst or metal salt. Catalyst carrier. In the early days, the raw materials for producing activated carbon were wood, hard fruit shells or animal bones. Later, coal was mainly used. After carbonization and activation treatment, activated carbon was obtained. The production methods include: ① Steam and gas activation method. Use water vapor or carbon dioxide to activate carbon at 850 to 900°C. ②Chemical activation method. Activated carbon can be obtained by using the gas released by the activator or impregnating the raw materials with the activator after high-temperature treatment.
Activated carbon has a microcrystalline structure. The arrangement of the microcrystals is completely irregular. There are micropores (radius less than 20 [angstrom] = 10-10 meters), transition pores (radius 20~1000), and macropores in the crystal. (radius 1000~100000), giving it a large inner surface with a specific surface area of ??500~1700 m2/g. This determines that activated carbon has good adsorption properties and can adsorb metal ions, harmful gases, organic pollutants, pigments, etc. in wastewater and exhaust gas. The industrial application of activated carbon also requires high mechanical strength and good wear resistance. Its structure should be stable and the energy required for adsorption should be small to facilitate regeneration. Activated carbon is used for decolorization and deodorization of oils, beverages, food, and drinking water, gas separation, solvent recovery, and air conditioning. It is used as a catalyst carrier and an adsorbent for gas masks.
Also known as activated charcoal, the foreign name of medicinal charcoal is Charcol. Indications: Used for diarrhea, flatulence, food poisoning, etc. Dosage and Usage Oral administration: 1.5~4g each time, 2~3 times a day, before meals. You can also take magnesium sulfate after taking this product to expel toxic substances. Note: It can absorb vitamins, antibiotics, sulfonamides, alkaloids, lactase, hormones, etc. It also affects the activity of protease and trypsin, so it is not suitable to be used together. Specifications Tablets: 0.15g, 0.3g, 0.5g each.
Physical properties:
Activated carbon is a kind of multi-pore carbonized material with extremely rich pore structure and good adsorption characteristics. Its adsorption is based on physical and chemical adsorption. It is made of force and its appearance is black. In addition to the main carbon, its ingredients also include a small amount of hydrogen, nitrogen, and oxygen. Its structure is shaped like a hexagon. Due to the irregular hexagonal structure, it determines its large size and high surface area. Characteristics: Each gram of activated carbon has a specific surface area equivalent to 1,000 square meters.
Activated carbon material:
Activated carbon is mainly made of substances with high carbon content, such as wood, coal, fruit shells, bones, petroleum residues, etc. Coconut shell is the most commonly used raw material. Under the same conditions, the active quality and special characteristics of coconut shell are the best because it has the largest specific surface.
Cost of activated carbon:
If the cost of activated carbon is calculated based on raw materials, the most expensive is coconut shell, followed by wood quality and coal quality, but activated carbon can have many levels of deep processing, the same Different deep processing of products will also cause great differences in costs. Customers mainly need to choose the corresponding activated carbon products based on their actual application conditions.
Production process:
According to the production method, activated carbon can be divided into physical water vapor method and chemical method. Here we focus on the production of physical water vapor method. Generally, production is divided into two processes. , The first step, carbonization, is to dry the raw materials at a temperature of 170 to 600 degrees Celsius, and carbonize 80% of their organic tissues in the same amount. The second step is activation. The carbonized material that has been carbonized in the first step is sent into the reactor to react with the activator and water vapor to complete the activation process and make the finished product. During the endothermic reaction process, CO and H2 combined gases are mainly produced, which are used to heat the carbonized material to an appropriate temperature (800 to 1000 degrees), remove all decomposable materials, and produce a rich pore structure and a huge specific surface area. Make activated carbon have strong adsorption power. Activated carbon produced from different raw materials has different pore sizes. Among them, the pore size of activated carbon made from coconut shell is the smallest, the pore size of wood-based activated carbon is generally larger, and the pore size of coal-based activated carbon is between the two. Activated carbon pore sizes are generally divided into three categories: macropores: 1000-1000000A, transition pores: 20-1000A, micropores: 20A. According to the above characteristics, it can be seen that for different adsorption objects, corresponding activated carbon needs to be selected to achieve the best cost performance. , therefore, generally in liquid phase adsorption, activated carbon with more transition pore sizes and larger average pore size should be selected.
Activated carbon application:
According to the adsorption characteristics of activated carbon, activated carbon is mainly used to remove pollutants in water, decolorize, filter and purify liquids and gases, and is also used to purify air. Waste gas recovery (such as the recovery of gas "benzene" in the chemical industry), precious metal recovery and refining (such as the absorption of gold). With the development of science, the uses of activated carbon are becoming more and more widespread. As the country attaches great importance to the ecological environment, activated carbon is also playing an increasingly important role.
The application of activated carbon is a very mysterious knowledge of activated carbon, and it is currently the weakest link in the technical field in our country. Compared with direct users, the most important thing is application knowledge. Meibao Company has been insisting on this for many years. We have been relentlessly engaged in research in the application field and accumulated a certain amount of application knowledge. We believe that with our efforts, we can help customers choose the most suitable activated carbon.
Reference: Baidu Encyclopedia The porous structure of activated carbon gives it super adsorption capacity. Many chemical stores and supermarkets They are all sold here, but if you put them in your home to absorb the smell of decoration, the amount required will be very large. It is recommended that you use ordinary charcoal and make a few hundred kilograms of it to put in your home. It can have the same effect, but the price will be higher. The structure of activated carbon, which is much cheaper, cannot simply be described as a network structure, because generally speaking, it is a loose porous structure, which should be three-dimensional, and the network feels flat. As for the atomic structure, it is hexagonal. Structure, arranged in layers.
Uses: Activated carbon is internationally recognized as an expert in taking drugs. Activated carbon masks and gas masks all use activated carbon.
Multiple uses: water purification for fish tanks, preservation of calligraphy and painting ancient books that are most afraid of mold and insect bites, disinfection and deodorization in refrigerators, bathrooms, and cars. Activated carbon is a powerful assistant for human anti-virus, detoxification, decolorization, and deodorization. Activated carbon is a porous adsorbent with various shapes, such as columnar granular carbon series, irregular broken carbon series, spherical carbon series, powdered carbon series, etc. Dozens of varieties. It is widely used in drinking water purification, air purification, wastewater treatment, food decolorization, solvent recovery and other fields. Different uses require different varieties. You can consult the manufacturer. Activated carbon is a type of microcrystalline carbon material made of carbonaceous materials with a black appearance, developed internal pore structure, large specific surface area and strong adsorption capacity. It is a commonly used adsorbent, catalyst or catalyst carrier. According to the source of raw materials, activated carbon can be divided into: wood activated carbon, fruit shell activated carbon, animal bone/blood activated carbon, mineral raw activated carbon, synthetic resin activated carbon, rubber/plastic activated carbon, regenerated activated carbon, etc.; activated carbon can be divided into: powder, granular according to appearance Shape, irregular granular shape, cylindrical shape, spherical shape, fibrous shape, etc. Activated carbon has an extremely wide range of applications, involving almost all national economic sectors and people's daily lives, such as water purification, gold extraction, sugar liquid decolorization, pharmaceutical injection refining, blood purification, air purification, human safety protection, etc.