How to activate and regenerate the activated carbon in the chromatography purifier?

After using it for a period of time, the adsorption capacity of activated carbon is greatly reduced, that is, it loses its activity. We can take out the activated carbon, dry it in a cool place, and then heat it in a microwave for 30 seconds to restore its activity. You might as well give it a try. You don’t need to replace activated carbon frequently, and you can save a lot of money! !

So at what temperature and how long should it be left in the oven?

Due to the regeneration of activated carbon in the chromatographic purifier, the thermal regeneration method can be considered, which is currently the most mature method, with a temperature of 800-900 °C. In order to avoid the oxidation of activated carbon, it is usually carried out under vacuum or in an inert atmosphere. During the activation stage, gases such as CO2, CO, H2 or water vapor are introduced to clean the micropores of the activated carbon and restore its adsorption performance. If you only dry it in an oven, you can only remove some of the low-boiling impurities adsorbed in the activated carbon, and the performance of the activated carbon will be restored, but it will not be completely restored. You can also take a look at the following methods excerpted from a review article on activated carbon regeneration methods. I hope they will be useful.: 1 Traditional activated carbon regeneration method 1.1 Thermal regeneration method Thermal regeneration method is currently the most widely used and the most mature activated carbon regeneration method in industry. The regeneration process of activated carbon after treating organic wastewater is generally divided into three stages: drying, high-temperature carbonization and activation according to the changes in organic matter when heated to different temperatures. In the drying stage, the volatile components on the activated carbon are mainly removed. The high-temperature carbonization stage is to boil, vaporize and desorb part of the organic matter adsorbed on the activated carbon. A part of the organic matter undergoes a decomposition reaction to generate small molecular hydrocarbons and desorb out. The remaining components remain in the pores of the activated carbon to become "fixed carbon". At this stage, the temperature will reach 800~900 °C. In order to avoid oxidation of activated carbon, it is usually carried out under vacuum or in an inert atmosphere. In the next activation stage, gases such as CO2, CO, H2 or water vapor are introduced into the reactor to clean the micropores of the activated carbon and restore its adsorption performance. The activation stage is the key to the entire regeneration process. Although the thermal regeneration method has the characteristics of high regeneration efficiency and wide application range, during the regeneration process, external energy heating is required, and the investment and operating costs are high. 　　1.2 Biological Regeneration Method The biological regeneration method uses domesticated bacteria to analyze the organic matter adsorbed on the activated carbon and further digest and decompose it into H2O and CO2. The biological regeneration method is similar to the biological method in sewage treatment, and there are also aerobic methods and anaerobic methods. Since the pore size of activated carbon itself is very small, some are only a few nanometers, microorganisms cannot enter such pores. It is generally believed that cell autolysis will occur during the regeneration process, that is, cellular enzymes flow out of the cells, and activated carbon has an adsorption effect on enzymes, so an enzymatic center is formed on the surface of the carbon, thereby promoting the decomposition of pollutants and achieving the purpose of regeneration. 　　Biological methods are simple and easy to implement, with low investment and operating costs, but they require a long time and are greatly affected by water quality and temperature. Microorganisms that treat pollutants are highly targeted and need to be specially adapted to specific substances. Moreover, during the degradation process, all organic matter cannot be completely decomposed into CO2 and H2O. The intermediate products still remain on the activated carbon and accumulate in the micropores. The regeneration efficiency will be significantly reduced after multiple cycles. This limits the industrial application of biological regeneration methods. 　　1.3 Wet oxidation regeneration method is a treatment method that uses oxygen or air as an oxidant under high temperature and high pressure conditions to oxidize and decompose organic matter adsorbed on activated carbon in a liquid phase into small molecules, which is called wet oxidation regeneration method. The regeneration conditions are generally 200~250 °C, 3~7MPa, and the regeneration time is mostly within 60min. The wet oxidation regeneration method has a wide range of treatment targets, short reaction time, stable regeneration efficiency, and no additional heating is required after regeneration starts. However, for some refractory organic compounds, more toxic intermediate products may be produced. 　　Using the change of phenol adsorption isotherm as the evaluation criterion, the School of Environment of Tongji University systematically studied the main influencing factors in the wet oxidation regeneration process of activated carbon, and theoretically discussed its regularity; explored the synergy between the main factors; examined the possibility of multiple cycle regeneration of saturated carbon; and studied the changes in the structure of activated carbon itself during the wet oxidation process. The optimal activated carbon regeneration conditions obtained experimentally are: regeneration temperature 230 °C, regeneration time 1 h, oxygenation pO20. 6MPa, carbon addition amount 15 g, water addition amount 300 mL. The regeneration efficiency reaches (45±5)%, and after 5 cycles of regeneration, the regeneration efficiency only drops by 3%. Partial oxidation of micropores on the surface of activated carbon is the main reason for the decrease in regeneration efficiency. 　　In addition to their respective drawbacks, traditional activated carbon regeneration technology usually has three common defects: (1) The loss of activated carbon during the regeneration process is often large; (2) The adsorption capacity of activated carbon will be significantly reduced after regeneration; (3) The exhaust gas generated during regeneration will cause secondary pollution of the air. Therefore, people either improve traditional regeneration technologies or explore new regeneration technologies. 　　2 Currently Emerging Activated Carbon Regeneration Technology 2.1 Solvent Regeneration Method The solvent regeneration method utilizes the phase equilibrium relationship between activated carbon, solvent and adsorbed matter. By changing conditions such as temperature and solvent pH value, the adsorption balance is broken and the adsorbed matter is desorbed from the activated carbon. This regeneration process is generally achieved through the following three approaches: changing the chemical properties of the pollutants; using a solvent with a stronger affinity for the pollutants than activated carbon for extraction; using a substance with a stronger affinity for activated carbon than the pollutants for replacement (generally only used for the purpose of adsorbent recovery). According to the different solvents used, it can be divided into inorganic solvent regeneration method and organic solvent regeneration method. 　　The inorganic solvent regeneration method mainly uses inorganic acid (H2SO4, HCl, etc.) or alkali (NaOH, etc.) as the regeneration solvent. Ye Liyi of Xiamen University and others studied the adsorption equilibrium relationship of phenol and p-chlorophenol aqueous solutions on activated carbon, the effect of solution pH on the adsorption performance of activated carbon, and the adsorption and desorption kinetics of phenol on a fixed bed. At the same time, the batch method and the fixed bed continuous method were used to study the alkali regeneration process of activated carbon after adsorbing phenol, as well as the impact of multiple regenerations on the regeneration efficiency of activated carbon, and the preliminary rules for regenerating activated carbon with alkaline solvents were discussed. Zhang Guojin and Zhou Yongzhang from the School of Materials Science and Engineering of Nanjing University of Chemical Technology used a new organic regeneration solvent (ZL) to regenerate activated carbon in printing and dyeing wastewater treatment. The regenerant is a colorless and transparent compound organic solvent that can be used repeatedly after distillation. It has high promotion value for some manufacturers with recyclable waste heat. 　　The solvent regeneration method is more suitable for those reversible adsorptions, such as the adsorption of high-concentration, low-boiling-point organic wastewater. It is highly targeted, and often a solvent can only desorb certain pollutants. However, there are many types of pollutants in the water treatment process and they vary, so the application range of a specific solvent is narrow. 　　2.2 Electrochemical regeneration method The electrochemical regeneration method is a new type of activated carbon regeneration technology being studied. In this method, activated carbon is filled between two main electrodes, and a DC electric field is applied to the electrolyte. The activated carbon is polarized under the action of the electric field. One end becomes the anode and the other end becomes the cathode, forming a micro-electrolytic cell. Reduction and oxidation reactions can occur at the cathode and anode parts of the activated carbon respectively. Most of the pollutants adsorbed on the activated carbon are decomposed as a result, and a small part is desorbed due to the electrophoretic force. This method is easy to operate, has high efficiency and low energy consumption, and has fewer limitations on the treated objects. If the treatment process is perfect, secondary pollution can be avoided. 　　Zhang Huiping, Fu Zhihong and others from the Department of Chemical Engineering of Xiamen University studied the effect of pH value on the adsorption balance of phenol on activated carbon, the electrochemical regeneration efficiency of activated carbon on different electrodes and the effect of cycle regeneration on the regeneration efficiency of activated carbon. Based on the analysis of relevant research results, they believe that the electrochemical regeneration process mechanism of activated carbon includes processes such as electrodesorption, NaOH alkali regeneration, and NaClO chemical oxidation. Experimental results show that electrochemically regenerated activated carbon has a high regeneration efficiency, which can reach 90%. In addition, research on process parameters shows that the regeneration position is the most important influencing factor in the activated carbon regeneration process, the electrolyte NaCl concentration is the more important influencing factor, and the regeneration current and regeneration time also have a certain impact on the electrochemical regeneration of activated carbon. 2.3 Supercritical fluid regeneration method When the temperature and pressure of a substance are higher than its critical temperature and critical pressure, it is called a supercritical fluid. Many substances have very little ability to dissolve certain solutes under normal pressure and temperature, but have unusually large dissolving abilities in subcritical states (nearly critical) or supercritical states. In the supercritical state, slightly changing the pressure will cause an order of magnitude change in solubility. Taking advantage of this property, supercritical fluid can be used as an extraction agent to achieve separation of solutes by adjusting the operating pressure, which is supercritical fluid extraction technology. The critical temperature of carbon dioxide is 31°C, which is close to normal temperature. The critical pressure (7.2 MPa) is not very high. It has the advantages of being non-toxic, non-flammable, not polluting the environment, and easy to obtain a supercritical state. It is the preferred extraction agent in the application of supercritical fluid extraction technology. According to recent research data, the regeneration efficiency changes greatly near the critical point of CO2; for activated carbon that has not been dried, the regeneration time needs to be extended. For p-aminobenzene sulfonic acid, the optimal temperature for CO2 supercritical fluid method regeneration is 308 K. When the temperature exceeds 308K, regeneration is not affected; when the flow rate is greater than 1. 47×10-4m/s, the flow rate does not affect regeneration; after treatment with HCl solution, the activated carbon regeneration effect will be significantly improved. For benzene, the regeneration efficiency decreases with the decrease of temperature at low pressure; the optimal regeneration temperature at 16.0 MPa pressure is 318 K; at the experimental flow rate, the regeneration efficiency increases with the increase of flow rate. 　　2.4 Ultrasonic regeneration method Since thermal regeneration of activated carbon requires heating all activated carbon, adsorbed substances and a large amount of water to a higher temperature, sometimes even reaching the vaporization temperature, it consumes a lot of energy and the process equipment is complex. In fact, the purpose of regenerating activated carbon can be achieved by applying energy to the adsorption surface of activated carbon so that the adsorbed substances have enough energy to break away from the adsorption surface and return to the solution. Ultrasonic regeneration is proposed for this point. The biggest feature of ultrasonic regeneration is that it only applies energy locally, without heating a large amount of aqueous solution and activated carbon, so the energy applied is very small. 　　Research shows that after ultrasonic regeneration, the temperature of the regenerated discharge fluid only increases by 2 to 3°C. Each time 1 L of activated carbon is processed, an ultrasonic generator with a power of 50W is used for 120 minutes, which is equivalent to a power consumption of 100 kW h per m 3 of activated carbon regeneration. The loss of activated carbon for each regeneration is only 0. 6% to 0. 8% of the dry mass, and the water consumption is 10 times the volume of activated carbon. Wang Sanfan of Lanzhou Railway Institute conducted experiments on the ultrasonic regeneration method. The results show that ultrasonic regeneration has the advantages of low energy consumption, simple process and equipment, small loss of activated carbon, and recovery of useful substances. However, it is only effective for physical adsorption, and the current regeneration efficiency is only about 45%, and the pore size of activated carbon has a great impact on the regeneration efficiency. 　　2.5 Microwave irradiation regeneration method Microwave irradiation regeneration method is an activated carbon regeneration technology developed on the basis of thermal regeneration method. The principle is to use electricity as energy source and use microwave irradiation and heating to achieve regeneration. Fu Dafang and others from Southeast University studied the microwave regeneration conditions of activated carbon adsorbed sodium dodecylbenzene sulfonate, using the change in iodine value of new carbon as the evaluation criterion. Through orthogonal experiments, the relationship between activated carbon regeneration efficiency and factors such as microwave power, microwave irradiation time, and the adsorption amount of activated carbon was explored. The best regeneration efficiency in the test occurred when the power was HI(W) and the irradiation time was about 80 s. Comparing the range S, it can be seen that the microwave power has the greatest impact on the recovery of the iodine value of activated carbon after regeneration, followed by irradiation time, and finally the adsorption amount of activated carbon. The microwave irradiation method takes a short time to regenerate activated carbon. It has low energy consumption and simple equipment structure, and has good application prospects. However, whether other intermediate products are produced during the desorption process of organic matter by microwave heating remains to be further studied. 　　2.6 Catalytic wet oxidation method The traditional wet oxidation method has low regeneration efficiency and high energy consumption. Regeneration temperature is the main factor affecting regeneration efficiency, but increasing the regeneration temperature will increase the surface oxidation of activated carbon, thereby reducing the regeneration efficiency. Therefore, people consider using high-efficiency catalysts to regenerate activated carbon using catalytic wet oxidation. Research on water environment control and resource utilization at Tongji University * * Researchers in key laboratories are conducting research in this area. As the concept of sustainable development becomes more and more popular, activated carbon regeneration technology and technology have attracted increasing attention. Some traditional activated carbon regeneration technologies and processes have made new improvements and breakthroughs in recent years. At the same time, new regeneration technologies are constantly emerging. Although these emerging technologies are not yet mature in terms of process routes, they are not currently available for industrial use. But their emergence has brought new ideas and new discussions to the regeneration of activated carbon.

It is strongly recommended that technical discussants often come to analyze the section guidance to improve the influence and popularity of this section and provide some suggestions of their own.

Well, except that I can't access the Internet, I will come and check it out every day. My level of knowledge is limited, so I will try my best to answer questions that I have a little understanding of. I also hope that I can learn more knowledge in the process of communicating with everyone. Welcome to communicate more.

Supporting the fourth floor's point of view, it is best to introduce CO2, CO, H2, N2 and other gases and activate them at high temperatures. The failure of activated carbon is generally caused by adsorption of mechanical impurities or other harmful substances, or reaction with the medium.

I would rather suggest that the forum have more practical things. The practices quoted on the fourth floor are all practices of research institutes and are far from actual general applications. You can take a look and see how many conditions you can achieve. In actual applications, it is usually 180 degrees, inert gas, micro flow, 3 to 4 hours is enough. The maximum temperature should not exceed 270 degrees. If you want to dehumidify at over-temperature, it is recommended to replace all the fillers with new ones! However, this must be done before using the new filler. The poster wants to save money and trouble, so I will teach you how to connect another filter in parallel and use a manual valve to switch. This way, it can be ensured that when activating the filter, it will not affect your work. It’s much easier to do things. Personal opinion. This post was last edited by chengjingbao on 2009-2-12 19:16 ]

Experts are not allowed to be modest. I have seen many of your posts. Your level is so high that I deserve the title of expert.

The activated carbon in the chromatographic purifier can be regenerated by heating the chromatographic column box at 200-300°C and backflushing with nitrogen for 4-24 hours. The time mainly depends on the temperature and the degree of pollution.