Introduction to basic knowledge of Activated Carbons
Activated Carbons is a traditional and modern man-made material, also known as carbon molecular sieve. Since its inception, the application fields of Activated Carbons and honeycomb activated carbon have been expanding, and the number of applications has continued to increase. Due to the different sources of raw materials, manufacturing methods, appearance shapes and applications, there are many types of activated carbon, about thousands of varieties. Activated carbon classification method: classification by material, shape, and purpose. Activated carbon is classified by material 1. Coconut shell charcoal Coconut shell activated carbon is made of high-quality coconut shells from Hainan, Southeast Asia and other places. The raw materials are screened, refined by steam carbonization, and then processed through a series of processes such as impurity removal and activation screening. Coconut shell activated carbon is black granular, with developed pore structure, high adsorption capacity, high strength, stable chemical properties, and durability. 2. Nutshell charcoal Nutshell activated carbon is mainly made of nutshell and sawdust as raw materials, through carbonization, activation, and refined processing. It has the characteristics of large specific surface area, high strength, uniform particle size, developed pore structure, and strong adsorption performance. And can effectively absorb free chlorine, phenol, sulfur, oil, gum, pesticide residues and other organic pollution in the water, as well as the recovery of organic solvents. It is suitable for the decolorization, refining, purification and sewage treatment of organic solvents in the pharmaceutical, petrochemical, sugar, beverage, and alcohol purification industries. Nutshell activated carbon is widely used in the deep purification of drinking water, industrial water and wastewater, and the purification of industrial water. 3. Wood charcoal Wood charcoal is made of high-quality wood as raw material, in powder form, refined by high-temperature carbonization, activation and various processes to make wooden activated carbon. It has a large specific surface area, high activity, developed micropores, strong decolorization power, and large pore structure, etc. Features, large pore structure, can effectively absorb the color and other large substances and impurities in the liquid. 4. Columnar carbon Columnar charcoal is made from high-quality wood chips, charcoal, etc., which are crushed, mixed, extruded, formed, dried, carbonized, and activated. Compared with traditional coal-based columnar activated carbon, the columnar activated carbon has lower ash content, less impurities, reasonable pore size distribution, and good adsorption and desorption, which greatly improves the service life of the product (average 2-3 years). It is the same as that of ordinary coal-based carbon. 1.4 times. 5. Coal-based charcoal Coal-based carbon is refined from high-quality anthracite coal as raw materials. The shapes are columnar, granular, powder, honeycomb, spherical and other shapes. It has the characteristics of high strength, fast adsorption speed, high adsorption capacity, large specific surface area, and developed pore structure. . The pore size is between coconut shell activated carbon and wood activated carbon. Mainly used for air purification, exhaust gas purification, high-purity water treatment, wastewater treatment, sewage treatment, etc.
Carbon molecular sieve adsorption and desorption process
The main component of Carbon molecular sieve is elemental carbon, and the appearance is a dark gray cylindrical solid. Because it contains many microporous plates with a diameter of 4 angstroms, the microporous plates have a strong instant appeal to oxygen molecules, and can be used to extract CO2 and N2 in the air. Pressure swing adsorption machinery and equipment ( PSA) Make N2. Carbon molecular sieve has a large nitrogen production capacity, a high N2 utilization rate, and a long service life. It can be used with various specifications and models of pressure swing adsorption nitrogen generators. It is a product of pressure swing adsorption nitrogen generators. Carbon molecular sieve air separation nitrogen production has been widely used in petrochemical equipment, machinery and equipment, metal surface solution, electronic component production and processing, vegetable preservation and other industries. Basic concept of production process Carbon molecular sieve absorption and treatment of organic waste gas is the application of Carbon molecular sieve microplates to digest and analyze the characteristics of chemical compounds, and absorb the organic solvents in the lower concentration of analytical chemical industrial waste gas into Carbon molecular sieve. After purification, the gas after suction and cleaning up to the standard is emptied immediately. The essence is a physical absorption and purification process. The organic solvents are not disposed of. Absorption is the use of the remodeling machinery and equipment produced by our company to melt the organic waste gas caused by the air heating of the organic solvent absorbed in the Carbon molecular sieve to ensure the melting point of the solvent, so that the organic solvent is absorbed from the Carbon molecular sieve And introduce the purified industrial waste gas with a higher concentration value into the catalytic combustion device equipment. The oxidation-reduction reaction of organic waste gas with a higher concentration value in the remodeling machinery and equipment reflects the conversion into harmless water and carbon dioxide into the gas. Absorption can be carried out in addition, using multiple Carbon molecular sieve adsorption beds for adsorption treatment, in addition to one bed for adsorption development prospects, suitable for continuous production and processing sites. Advantages of production process 1. High professional ability to absorb organic molecules in industrial waste gas; 2. High temperature resistant and not easy to corrode; 3. Molecular sieves can be continuously reshaped. The catalytic reaction speed is used to reshape the machinery and equipment to reshape it on time, and the concentrated gas produced in the manufacturing process enters the remolding machinery and equipment and is compounded, resulting in harmless gas sewage treatment and difficult to correct Geographical environment causes secondary pollution; 4. It saves operating costs and does not need to be disassembled on time like activated carbon.
What factors affect the Carbon molecular sieve of the nitrogen generator
Many people don't know Carbon molecular sieve very well and don't know what it is. Just grasp some industry-related professional skills in the industry, such as Carbon molecular sieve for nitrogen generators. Carbon molecular sieve is based on the characteristics selected to ensure the purpose of dissolving co2 and N2. When Carbon molecular sieve absorbs sediment vapor, the holes and vertical holes are only used as safety exits for safety exits, and the absorbed molecular formula is transported to the microwell and submicrowell plates, and the microwell and submicrowell plates are Actual digestion capacity. The outside of the Carbon molecular sieve includes many microplates, which can quickly disperse molecular formulas with smaller mechanical energy specifications into the pores, and restrict the entry of large-diameter molecular formulas. Due to the difference in relative dispersion speed of vapor molecular formulas of different specifications and models, the composition of vapor ginseng dirt can be dissolved very well. Therefore, during the production and processing of Carbon molecular sieve, according to the molecular size specification, the microplates on both sides of the Carbon molecular sieve should diffuse in the middle of 0.28~0.38nm. In this type of microplate specifications, co2 can be quickly dispersed into the wells according to the microplate holes, but nitrogen cannot be based on the microplate holes, so oxygen and nitrogen are dissolved. The diameter of the microplate is the basis for selecting co2 and N2 based on carbon. If the diameter is very large, the carbon molecular sieve of oxygen and nitrogen can easily enter the microplate, and the expected effect of dissolution cannot be guaranteed. When the diameter is too small, neither oxygen nor nitrogen can enter the microplate, nor can it have a dissolving effect. 1. Pressure reducing valve on the pipeline As a result, the maintenance of nitrogen equipment has improved personal preference, and the characteristics of mechanical equipment have decreased. Therefore, the use of imported valves has solved the root cause of the thin link of the Carbon molecular sieve nitrogen generator. For traditional PSA nitrogen generators, it is very important to solve the sensitivity, service life and maintenance difficulties of its constituent valves. Some household shut-off valves have a higher maintenance rate. 2. The importance of PSA nitrogen production equipment The use of Carbon molecular sieve ensures the use of Carbon molecular sieve, Carbon molecular sieve bottling expertise and Carbon molecular sieve automatic filling equipment. Compared with other similar nitrogen generators, it increases the nitrogen utilization rate and reduces the energy consumption of the nitrogen generator by 1525%, thus ensuring the service life of the Carbon molecular sieve and reducing the carbon molecular sieve’s absorption of tables and benches. "load". It improves the professional ability of carbon molecular sieve nitrogen generator. The characteristics of activated carbon industrial waste gas absorption equipment 1. It is very good for volatile organic compounds or peculiar smell, and the absorption of vapor meets the requirements. 2. The expected effect is very good for the lower concentration of volatile organic compounds. Activated carbon is used repeatedly to control the cost 3. The processing air volume is large, and the expected effect of suction is high. 4. Easy to disassemble activated carbon.
Uses of Carbon Molecular Sieve
Carbon Molecular Sieve is a new type of adsorbent developed in the 1970s, and it is an excellent non-polar carbon material. In the 1950s, along with the tide of the industrial revolution and the continuous improvement of technology, people discovered that carbon molecules and their powerful adsorption and filtration capabilities could even separate different components. In this case, carbon molecular sieve came into being. Carbon molecular sieve is actually a kind of small particles similar to activated carbon, which are full of holes. It is precisely because of these holes in carbon molecular sieve that carbon molecular sieve is used as air molecular raw material in industrial production. For example, carbon molecular sieve is used as raw material to separate air. Nitrogen is produced through adsorption compression technology. Nitrogen carbon molecular sieve is used to separate air and enrich nitrogen. It adopts normal temperature and low pressure nitrogen production process. Compared with the traditional cryogenic high pressure nitrogen production process, it has the advantages of lower investment cost, fast nitrogen production speed and low nitrogen cost. Therefore, it is currently the preferred pressure swing adsorption nitrogen-rich adsorbent for air separation in the engineering industry. This nitrogen is used in the chemical industry, oil and gas industry, electronics industry, food industry, coal industry, pharmaceutical industry, cable industry, metal heat treatment, transportation and Widely used in storage and other aspects.
Brief description of activated alumina catalyst types in exhaust gas treatment
There are many types of activated alumina catalysts in exhaust gas treatment, and the classification methods are also different. According to the big aspects, it can be divided into acid-base catalysts, metal catalysts, semiconductor catalysts and molecular sieve catalysts. Their common feature is that they can produce different degrees of chemical adsorption on reactants. Therefore, catalysis is inseparable from adsorption, and the general catalytic process starts with adsorption. 1. Acid-base catalysts referred to here are acids and bases in a broad sense, that is, Lewis acids and Lewis bases. Both of them can provide acid-base active adsorption centers for chemisorption of reactants, thereby promoting chemical reactions. Such as activated clay, aluminum silicate, aluminum oxide and oxides of some metals, especially oxides of transition metals or their salts. 2. Metal catalyst Metal adsorption capacity depends on the molecular structure and adsorption conditions of the metal and gas. It was found through experiments that metal elements with d-electron empty orbits have different chemical adsorption capacities for some representative gases. Except for Ca, Sr, and Ba, most of these metals are transition metals. They rely on electrons or unbound electrons that do not participate in the hybrid orbitals of the metal bond to form adsorption bonds with the adsorbent molecules, which catalyzes the interaction between them Reaction. 3. Semiconductor catalysts are mainly some semiconductor-type transition metal oxides. They are divided into n-type semiconductors and p-type semiconductors in order to provide quasi-free electrons or quasi-free holes. The n-type semiconductor catalyst relies on its quasi-free electrons to form adsorption bonds with the reactants; the p-type semiconductor catalyst relies on its quasi-free holes to form adsorption bonds with the reactants. Due to the formation of adsorption bonds, the conductivity of the semiconductor is changed, which is one of the main factors affecting the activity of the catalyst. In fact, the formation of adsorption bonds between gas molecules and semiconductor catalysts is a very complicated process. In the study of the catalytic mechanism of semiconductors, it was also found that the energy bands due to electronic transitions play an important role in the formation of adsorption bonds. effect. Therefore, it cannot be simply assumed that a reactant molecule capable of donating an electron can only form an adsorption bond with a p-type semiconductor catalyst. 4. Zeolite molecular sieve catalyst is widely used as an adsorbent in drying, purification, separation and other processes. It began to make its appearance in the application of catalysts and catalyst carriers in the 1960s. Zeolite refers to the natural crystalline aluminosilicate, which has the same diameter micropores, so it is also called molecular sieve. At present, there are more than hundreds of species, and many important industrial catalytic reactions are inseparable from molecular sieve catalysts. The catalysis of molecular sieve also relies on acidic centers on its surface to form adsorption bonds. However, it is more selective than acid-base catalysts because it can reject molecules with a larger pore size from entering the inner surface. At the same time, the acidity and alkalinity on the surface of the molecular sieve can also be adjusted artificially by means of ion exchange, which has better performance than ordinary acid-base catalysts. In recent years, a kind of non-silicon-aluminum-based synthetic molecular sieve has been developed and has been widely used in the field of catalysis. It can be seen that molecular sieve has its special status and role in the field of catalysis.
Advantages and replacement of activated carbon and carbon molecular sieve in psa nitrogen generator
Carbon molecular sieve is a new type of adsorbent developed in the 1970s. It is an excellent non-polar carbon material. It is mainly used to separate nitrogen from the air and enrich it with nitrogen. It is currently the first choice of PSA nitrogen generator in the engineering industry. This nitrogen is used in chemical industry, oil and gas industry, electronics industry, food industry, coal industry, pharmaceutical industry, cable industry, metal heat treatment, transportation and storage Widely used. Carbon molecular sieve uses the characteristics of sieving to achieve the purpose of separating oxygen and nitrogen. When the molecular sieve adsorbs impurity gases, the macropores and mesopores only serve as channels, and the adsorbed molecules are transported to the micropores and submicropores. The micropores and submicropores are the volumes that really play the role of adsorption. Due to differences in the relative diffusion rates of gas molecules of different sizes, the components of the gas mixture can be effectively separated. Therefore, when manufacturing a carbon molecular sieve, the micropore distribution inside the carbon molecular sieve should be 0.28 to 0.38 nm according to the size of the molecule. Within this micropore size range, oxygen can quickly diffuse into the pores through the micropore pores, but nitrogen can hardly pass through the micropore pores, thereby achieving oxygen and nitrogen separation. German BF molecular sieve, Japanese Takeda carbon molecular sieve, Japanese Iwatani molecular sieve, activated carbon for nitrogen generator, 13X molecular sieve, 5A molecular sieve, mainly used in pressure swing adsorption nitrogen production equipment. Molecular sieve is a new type of non-polar adsorbent, which has the property of adsorbing oxygen molecules in the air at normal temperature and pressure, so it can obtain nitrogen-rich gas. Maintenance method of nitrogen generator 1. The air outlet of the air storage tank is equipped with a timed drain to reduce the load pressure of the process. 2. The normal use of the equipment should pay attention to check whether each timing drain is draining normally, whether the air pressure meets above 0.6Mpa, and comparing the inlet and outlet of the cold and dry machine, whether there is a cooling effect. 3. The air filter must be changed at a frequency of 4,000 hours. 4. Activated carbon filter can effectively filter oil stains and prolong the service life of high-quality carbon molecular sieve. Activated carbon needs to be replaced every 3000 hours or 4 months. 5. Nitrogen generator pneumatic valve, solenoid valve is recommended for each model of the action components to prevent future problems. Activated carbon and carbon molecular sieve replacement steps: simply clean the site, cut off gas and power, two people remove the head of the adsorption tower, two people remove all the pipes of the nitrogen generator, remove the waste in the adsorption tower, you need to clean it, check the top of the adsorption tower And the bottom part of the flow plate is damaged, and the damage is repaired in time. All pipelines should be cleaned with compressed air, the pneumatic valve should be inspected for damage to the seal ring, and the pneumatic valve needs to be replaced seriously.
