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CN-121988289-A - Regenerated active carbon for VOCs treatment and preparation method thereof

CN121988289ACN 121988289 ACN121988289 ACN 121988289ACN-121988289-A

Abstract

The invention discloses regenerated active carbon for VOCs treatment and a preparation method thereof, and belongs to the technical field of active carbon regeneration. The method comprises the steps of (1) pretreatment, namely sequentially carrying out solvent desorption, activation and plasma treatment on activated carbon with saturated adsorption to obtain a regenerated activated carbon matrix, (2) MOF derivative rare earth doped surface modification, namely immersing the regenerated activated carbon matrix in an alcohol solution containing zinc salt and rare earth salt, adding a 2-methylimidazole ligand solution to enable a ZIF-8 metal organic framework to grow on the surface of the activated carbon in situ, and then carrying out carbonization treatment at 600-800 ℃ in inert atmosphere. The defect sites formed by plasma pretreatment are used as chemical anchor points for MOF growth, so that a firm chemical bonding structure is formed between the modified layer and the carbon skeleton, and the rare earth oxide nano particles formed in situ provide additional adsorption active sites, so that the broad-spectrum efficient adsorption of various VOCs is realized.

Inventors

  • ZHANG SIQI
  • WANG JINFENG
  • DAI RUXIN
  • HAN DONG

Assignees

  • 江苏乾汇和环保再生有限公司

Dates

Publication Date
20260508
Application Date
20260330

Claims (10)

  1. 1. The preparation method of the regenerated active carbon for VOCs treatment is characterized by comprising the following steps: (1) Pre-treatment, namely sequentially carrying out solvent desorption, activation treatment and plasma treatment on the activated carbon with saturated adsorption to obtain a regenerated activated carbon matrix; (2) And (3) MOF derivative rare earth doped surface modification, namely immersing the regenerated active carbon matrix into an alcohol solution containing zinc salt and rare earth salt, adding a 2-methylimidazole ligand solution to enable a ZIF-8 metal organic framework to grow on the active carbon surface in situ, and then carbonizing at 600-800 ℃ in an inert atmosphere to obtain the regenerated active carbon.
  2. 2. The preparation method of claim 1, wherein in the step (2), the zinc salt is zinc nitrate, the rare earth salt is one or two selected from yttrium nitrate and lanthanum nitrate, and the molar ratio of zinc ions to rare earth ions is 10:1-20:1.
  3. 3. The preparation method according to claim 1, wherein in the step (2), the alcohol solution is methanol, the zinc salt concentration is 0.05-0.15 mol/L, and the molar ratio of 2-methylimidazole to zinc ions is 4:1-8:1.
  4. 4. The preparation method of the ceramic material according to claim 1, wherein in the step (2), the in-situ growth condition is that stirring is carried out for 4-12 hours at room temperature, the temperature rising rate of the carbonization treatment is 4-6 ℃ per minute, and the carbonization time is 1-2 hours.
  5. 5. The preparation method of claim 1, wherein in the step (1), the solvent desorption adopts a composite desorption solvent, the composite desorption solvent is formed by mixing a polar solvent, a nonpolar solvent and a stripping aid according to a volume ratio of 5:3:2, the polar solvent is one or two of ethanol and acetone, the nonpolar solvent is n-hexane, and the stripping aid is polyethylene glycol 400.
  6. 6. The preparation method of claim 1, wherein in the step (1), the activation treatment is performed by using a composite activator of phosphoric acid and potassium carbonate, and the activation temperature is 450-500 ℃.
  7. 7. The preparation method of the plasma treatment device according to claim 1, wherein in the step (1), the condition of the plasma treatment is that a mixed gas of argon and oxygen is introduced, the power is 80-120W, the temperature is 60-80 ℃, and the treatment time is 15-25 min.
  8. 8. The preparation method of claim 1, wherein in the step (2), the inert atmosphere is nitrogen or argon, and the gas flow is 50-100 ml/min.
  9. 9. A regenerated activated carbon for VOCs remediation prepared by the method of any one of claims 1 to 8.
  10. 10. Use of the regenerated activated carbon of claim 9 in a volatile organic compound adsorption process.

Description

Regenerated active carbon for VOCs treatment and preparation method thereof Technical Field The invention relates to the technical field of activated carbon regeneration, in particular to regenerated activated carbon for VOCs treatment and a preparation method thereof. Background Volatile organic compounds (Volatile Organic Compounds, VOCs for short) are one of the main pollutants generated in the processes of industrial production, solvent use and the like, and have potential influence on the atmospheric environment and human health. The activated carbon adsorption technology has become one of the common technologies in the fields of VOCs purification and organic sewage treatment because of the characteristics of simple operation, large adsorption capacity, wide application range and the like, and is widely applied to the industries of chemical engineering, electronics, coating, printing and the like. However, activated carbon has a limited adsorption capacity, and requires regeneration treatment after saturation of adsorption. If the saturated activated carbon is directly abandoned, not only is the resource wasted, but also secondary pollution risks can be caused by the release of adsorbed pollutants. Therefore, the activated carbon regeneration technology has important significance for realizing the recycling of resources and reducing the comprehensive cost of VOCs treatment. At present, the active carbon regeneration technology mainly comprises high-temperature heat regeneration, solvent extraction regeneration, microwave regeneration and other methods, wherein the high-temperature heat regeneration is a technology with wider application. The technology generally needs to realize the regeneration of the activated carbon through the steps of drying, carbonization, activation and the like under the anoxic environment with higher temperature (such as 800-950 ℃), and can obtain higher recovery rate of adsorption capacity. However, the technology has the defects in practical application that on one hand, the energy consumption is high under the high-temperature condition, the microporous structure of the activated carbon is easily damaged, the carbon skeleton is graphitized to a certain extent, the specific surface area and the adsorption performance of the activated carbon can be attenuated after repeated cyclic regeneration, and on the other hand, the adsorbed organic matters can be subjected to pyrolysis reaction in the high-temperature process to generate tail gas which needs further treatment. In addition, in actual VOCs treatment and sewage treatment scenes, pollutant components are often complex, and often contain various components such as halogenated hydrocarbon, nitrogenous solvent and the like. Research shows that the mixed solvent system may cause the microporous structure of the regenerated active carbon to change, and the existence of halohydrocarbon or nitrogenous solvent may also influence the recycling performance of the active carbon. From the perspective of adsorption mechanism analysis, certain thermodynamic irreversibility exists in the adsorption-desorption process, and the diffusion rate of solvent molecules in micropores also can influence the desorption efficiency. The prior regeneration technology is designed aiming at a single pollutant system, has relatively few cooperative regulation and control researches on pore channel structures and surface functional groups, and still has room for improving the cycle service life of the activated carbon when multi-component complex pollutants are treated. In summary, the development of the regenerated active carbon capable of taking energy consumption control, adsorption performance recovery and cycle stability into consideration and the preparation method thereof has positive significance in improving VOCs treatment efficiency and promoting resource recycling. Disclosure of Invention Based on the problems existing in the background technology, the invention provides the regenerated active carbon for VOCs treatment and the preparation method thereof, and the method combines a pretreatment process of solvent desorption, activation treatment and plasma pretreatment with a MOF derived rare earth doped surface modification technology, so that the pore structure of waste active carbon can be effectively recovered, a rare earth doped porous carbon layer can be constructed on the surface of the waste active carbon, and the adsorption capacity and selectivity of the regenerated active carbon to VOCs are obviously improved. The invention is implemented by the following technical scheme: the preparation method of the regenerated active carbon for VOCs treatment comprises the following steps: (1) Pre-treatment, namely sequentially carrying out solvent desorption, activation treatment and plasma treatment on the activated carbon with saturated adsorption to obtain a regenerated activated carbon matrix; (2) And (3) MOF derivative rare earth doped surface