activated carbon
Thread Content
1. Introduction Activated carbon is a very excellent adsorbent. It is manufactured by using charcoal, bamboo charcoal, various fruit shells and high-quality coal as raw materials, through a series of processes such as crushing, screening, catalyst activation, rinsing, drying and screening of raw materials through physical and chemical methods. It has the dual characteristics of physical adsorption and chemical adsorption, and can selectively adsorb various substances in the gas phase and liquid phase to achieve the purposes of decolorization and refining, disinfection, deodorization, decontamination and purification. Inspection standards can be in accordance with China's national standard GB, or in accordance with other * * standards such as: American ASTM, Japanese JIS, German DIN standards, etc. The usage situation of powdered activated carbon in my country is as follows: 59.8% is used in medicine, 26.6% is used in oral glucose, 10.8% is used in the food industry, 2.8% is used in other aspects, and the usage situation of granular activated carbon in my country is as follows: 51.2% for synthetic fiber carriers 13.0% for polyvinyl chloride carriers 23.5% for air and water purification 7.7% for synthetic desulfurization 4.6% for other applications 2. Activated carbon applications Activated carbon is widely used in all aspects of industrial and agricultural production, such as alkali-free deodorization (refined demercaptan), ethylene desalted water (refined filler), catalyst carriers (palladium, platinum, rhodium, etc.), water purification and sewage treatment in the petrochemical industry ； Power plant water quality treatment and protection in the power industry ； Chemical catalysts and carriers, gas purification, solvent recovery and decolorization and refining of oils and greases in the chemical industry ； Refining and decolorizing of beverages, alcoholic beverages, MSG mother liquor and food in the food industry ； Gold extraction and tail liquid recovery in the gold industry ； Sewage treatment, waste gas and harmful gas control, and gas purification in the environmental protection industry ； As well as related industries such as cigarette filters, wooden floor moisture protection, odor absorption, automobile gasoline evaporation pollution control, preparation of various impregnation liquids, etc. Activated carbon will have excellent development prospects and a broad sales market in the future. Main uses of activated carbon: 1. Used for liquid phase adsorption activated carbon • Tap water, industrial water, electroplating wastewater, purified water, beverages, food, medical water purification and electronic ultrapure water preparation. •Decolorization, refining and impurity removal, purification and filtration of sucrose, xylose, monosodium glutamate, pharmaceuticals, citric acid, chemical products and food additives. Decolorization, impurity removal and deodorization of grease, oil, gasoline and diesel, purification, deodorization and impurity removal of alcohol and beverages. Purification, refining, decolorization and filtration of fine chemicals, pharmaceutical chemicals and biopharmaceutical process products. •Environmental engineering wastewater, domestic wastewater purification, decolorization, deodorization, COD reduction 2. Used for gas phase adsorption activated carbon • adsorption and recovery of organic solvents such as benzene, toluene, xylene, propylene, oil and gas, CS2. •Cigarette filters, decoration deodorization, indoor air purification (removal of formaldehyde, benzene, etc.), industrial gas purification (such as CO2, N2, etc.) • Petrochemical industry production, natural gas purification, desulfurization, deodorization, waste gas control • Air purification and deodorization in biochemical, paint industry, underground places, leather factories, animal breeding places. •Odor adsorption and sulfide adsorption of flue gas, removal of mercury vapor, and reduction of dioxin production. 3. Used in high-demand fields: activated carbon catalysts and catalyst carriers (palladium carbon catalyst, ruthenium carbon catalyst, rhodium carbon catalyst, platinum carbon catalyst), precious metal catalysts and synthetic diamond and gold extraction. •Blood purification, automotive carbon canisters, high-performance fuel cells, electric double layer supercapacitors, lithium battery anode materials, energy storage materials, * * , aerospace and other high-demand fields.
Activated carbon physical properties: Activated carbon is a multi-pore carbonized substance with an extremely rich pore structure and good adsorption characteristics. Its adsorption is achieved by physical and chemical adsorption forces, and its appearance is black. In addition to the main carbon, its ingredients also contain a small amount of hydrogen, nitrogen, and oxygen. Its structure is shaped like a hexagon. Due to the irregular hexagonal structure, it determines its characteristics of large body and high surface area. Each gram of activated carbon has a specific surface equivalent to 1,000 square meters. Activated carbon material: Activated carbon is mainly made from 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. production process: The production of activated carbon is generally divided into two processes. In the first step, carbonization, the raw materials are dried at a temperature of 170 to 600 degrees Celsius, and 80% of the organic tissue is carbonized 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, a combination of CO and H2 is mainly produced, which is used to heat the carbonized material to an appropriate temperature (800 to 1000 degrees), remove all its decomposable substances, and produce a rich pore structure and a huge specific surface area, making the 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:: big hole: 1000-1000000A transition hole: 20-1000A micropore: 20A Based on 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. Application of activated carbon: 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 for air purification, waste gas recovery (such as the recovery of gas "benzene" in the chemical industry), and the recovery and refining of precious metals (such as the absorption of gold). With the development of science, the uses of activated carbon are becoming more and more widespread. * * With the emphasis on the ecological environment, activated carbon is also playing an increasingly important role.
The author would like to ask if there are any unsaturated bonds on the surface of activated carbon? Is it because it has a good adsorption effect or because it has a specific surface area that it can adsorb a large amount of adsorbate?
Very good content, thank you to the author for your hard work
Is the poster engaged in activated carbon production? I want to do a small trial of the new technology in this area and need an operator.