What Are The Application Fields of Activated Carbon?

1. Water purification

Biological activated carbon refers to a new type of water purification carbon material that allows microorganisms to reproduce in the pores of activated carbon and has aerobic biological activity. Domestic and foreign research and practical applications have shown that in the in-depth treatment of drinking water, biological activated carbon has a good removal effect on chemical oxygen demand (COD), turbidity, and color in water, and has been successfully used in drinking water in many countries. Water treatment, sewage treatment, ozone-biological activated carbon process, etc., and can be regenerated by microorganisms and heating. Biological activated carbon takes advantage of the synergistic effect of adsorption and degradation and can be used as a highly purified water treatment method, and will be more popular in the future.

The development direction of activated carbon for water treatment is miniaturization and convenience. The activated carbon for water treatment can be regenerated and reused.

2. Pharmaceutical industry

Activated carbon is widely used in the pharmaceutical industry. Whether in biological preparations, synthetic chemical drugs, hormones, vitamins, injections, large infusions, etc., activated carbon is used as an adsorbent or catalyst carrier.

Activated carbon can separate vitamin A from carotene through selective adsorption. It can also separate vitamin A and vitamin D. It can also adsorb and aggregate vitamin G in whey and wash it out with hot water. Activated carbon can also decolorize and crystallize vitamin C to prevent vitamin C from being oxidized and converted into dehydroascorbic acid. Activated carbon can also adsorb hormones such as insulin, adrenocortical hormone, and posterior pituitary oxytocin, and then filter and extract the active ingredients adsorbed by the activated carbon.

Blood purification is one of the typical medical applications of activated carbon as an adsorbent, including hemoperfusion, hemodialysis, etc. Hemoperfusion activated carbon is in direct contact with blood cells. Biocompatible hydrophilic gels and polymer materials must be used to coat the activated carbon. Spherical activated carbon is usually used to remove substances that cause kidney disorders from the body by adsorbing them and reduce the accumulation of toxic substances in the body. , has passed clinical trials. Hemodialysis, also known as artificial kidney, is based on the principle of membrane balance. It passes the patient's blood through a membrane with many small holes to selectively supplement the substances needed in the body to achieve the purpose of removing harmful substances from the body. However, for the molecular substances in the blood, The removal effect is poor. Due to its excellent adsorption performance, activated carbon is insoluble in dialysate and will not penetrate the dialysis membrane. Therefore, it is an adsorbent for dialysate regeneration and can reduce the usage of dialysate.

3. Heavy metal recycling

The recovery of heavy metals has high economic benefits. The special activated carbon for metal adsorption developed by Norit can selectively adsorb heavy metal ions, and the adsorption rate is as high as 85%. This product is characterized by developed micropores, high strength, and high packing density. Fast attachment/desorption speed. Through activated carbon for heavy metal recovery, rare metals and heavy metals in ore seawater can be recovered, which has very objective economic benefits.

Used in the field of gas phase adsorption

There are many gas phase adsorption applications of activated carbon; mainly including indoor air purification, flue gas purification, oil and gas recovery, organic waste gas treatment, etc.

1. Indoor air purification

Compared with outdoor air pollution, indoor environmental pollution has more direct harm to health and is an important cause of allergies, asthma, immune diseases, etc. There are many sources of indoor environmental pollution, including building and decoration materials, kitchen fumes, furniture items, and tobacco smoke. As people pay more and more attention to the home environment, the market demand for activated carbon for indoor air purification is growing. Therefore, instant activated carbon air purification devices suitable for indoors will also become popular. According to the type and molecular size of indoor toxic gases, activated carbon with pore size control can remove odors, thereby eradicating indoor pollution.

Flue gas purification

Activated carbon adsorption desulfurization, denitrification, and mercury removal are the development trends of coal-fired flue gas dry purification technology, especially suitable for water-scarce areas. Activated carbon desulfurization technology is relatively mature abroad. Metals such as cobalt, shackles, knobs, and magnesium are loaded on activated carbon to improve the removal performance of sulfur dioxide. The Coal Chemical Branch of the Coal Science and Technology Research Institute Co., Ltd. is at the forefront of the country in activated carbon dry flue gas purification technology. The joint desulfurization, denitrification and dust removal of coal-fired flue gas has good results and has been industrialized. The treatment technology of coke oven flue gas Promotion is also ongoing.

Oil and gas recovery

With the continuous development of the automobile industry, automobile fuel volatilization has become a major cause of air pollution.

one of the important sources. Research shows that about 40% of total automobile pollution comes from oil and gas volatilization pollution, which accounts for 60% to 70% of tail gas emission pollution. In response to this problem, foreign researchers have developed activated carbon with efficient adsorption/desorption functions of oil and gas, and applied it to the recovery of volatile gasoline from automobiles, saving energy and protecting the environment. At present, the n-butane working capacity (BWC) of foreign activated carbon has increased from 90~110g/L a few years ago to 150g/L, and high-capacity, low-residue activated carbon for oil and gas recovery is also being continuously developed. Domestic enterprises have also begun to use activated carbon for oil and gas recovery. For example, Beijing Yanshan Petrochemical Refinery used an activated carbon oil and gas recovery device to recover 288 tons of gasoline in 2006, with a contract price of approximately RMB 1.5 million. This is only the gasoline recovery benefit of a single refinery under the condition that the oil and gas recovery rate is 0-24%. If it is scaled up to the whole country, tens of thousands of tons of oil and gas are discharged into the atmosphere every year. Effective recovery will have very considerable benefits. Economic benefits and environmental protection effects.

Adsorption of organic waste gas

With the acceleration of the global industrialization trend, more and more industries and types use organic solvents. In order to prevent these solvents from being directly discharged into the atmosphere during use and causing pollution, they must be recycled or purified. Activated carbon is widely used in the adsorption of organic solvents due to its low price and simple operation. After the activated carbon surface is inertized, high-concentration valuable organic gases are adsorbed/desorbed to avoid catalytic modification of organic solvents on the surface of activated carbon, resulting in the recovery of valuable organic solvents that cannot be reused. For low-concentration organic waste gas, it is recommended to use activated carbon loaded with metal catalysts to catalytically degrade the organic solvent into CO2 and H2O during the adsorption process: it is currently relatively easy to purify to a concentration level of 10-6. As the country attaches greater importance to environmental protection and resource recycling, the demand for a complete set of activated carbon recovery organic solvent systems will also increase.

1.5.3 As catalyst carrier

Metals or metal oxides used as catalysts have catalytic activity because they have active centers, and crystal defects are the main reason why the active centers can exist. Graphitized carbon and amorphous carbon are components of the crystalline form of activated carbon. Because they have unsaturated bonds, they behave like crystal defects. Activated carbon is widely used as a catalyst due to the existence of crystal defects, especially in oxygen reduction reactions such as flue gas desulfurization, phosgene oxidation, synthesis of dicyanogen chloride, ozone decomposition and oxygen depolarization in batteries. in this way. At the same time, because of its large internal surface area, activated carbon is also an ideal catalyst carrier, especially in the field of photocatalyst loading. Loading photocatalysts on activated carbon and using it for the degradation of organic waste gas will be an important direction for future development.

In response to market demand, developing products with application prospects is the future development direction of the activated carbon industry. Entrepreneurs and scientific researchers should regard activated carbon as a multifunctional new material, break away from traditional application fields, formulate reasonable short-term and medium-term development plans for enterprises, and gradually get out of business difficulties. In the foreseeable next few decades, the development prospects of the activated carbon industry in China are still very broad. While activated carbon continues to play an important role in traditional application fields, people have linked it to many new technologies such as new energy, membrane separation, clinical medicine, analytical sensors, chemical separation, etc. The development of these new application fields has made activated carbon products revitalized. new vitality. Of course, new applications also put forward new requirements for the development of activated carbon. Targeted development and modification of activated carbon according to application requirements will become one of the important directions of activated carbon research.