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CN-122006660-A - Preparation method of carbon-based adsorbent for refining and upgrading crude pyroligneous liquor

CN122006660ACN 122006660 ACN122006660 ACN 122006660ACN-122006660-A

Abstract

The invention discloses a preparation method of a carbon-based adsorbent for refining and upgrading crude pyroligneous liquor, and belongs to the field of biomass resource utilization. The preparation method comprises the steps of (1) mixing straw with an activating agent and drying to obtain a solid-phase mixture, wherein the activating agent comprises one of a zinc chloride solution, a phosphoric acid solution and a mixed solution of zinc chloride and phosphoric acid, (2) carrying out pyrolysis activation on the solid-phase mixture in an inert atmosphere, cooling after completion to obtain biomass-based pyrolytic carbon, and (3) washing and drying the biomass-based pyrolytic carbon to obtain the carbon-based adsorbent for refining and upgrading crude wood vinegar. The preparation method has the advantages of green environmental protection, convenient process and high production efficiency, and the prepared carbon-based adsorbent has the advantages of developed pore channel structure, concentrated pore size distribution and rich oxygen-containing functional groups, particularly has good adsorption characteristics for phenolic substances, and has wide application prospect in refining and upgrading crude pyroligneous liquor as an adsorption material.

Inventors

  • ZHANG HUIYAN
  • CHEN WENQI
  • WU GANG
  • Su yinhai
  • XIAO RUI

Assignees

  • 东南大学

Dates

Publication Date
20260512
Application Date
20260128

Claims (10)

  1. 1. The preparation method of the carbon-based adsorbent is characterized by comprising the following steps: (1) Mixing the straw with an activating agent, and drying to obtain a solid phase mixture, wherein the activating agent comprises one of zinc chloride solution, phosphoric acid solution and mixed solution of zinc chloride and phosphoric acid; (2) Carrying out pyrolysis activation on the solid phase mixture in an inert atmosphere, and cooling after completion to obtain biomass-based pyrolytic carbon; (3) And washing and drying the biomass-based pyrolytic carbon to obtain the carbon-based adsorbent for refining and upgrading the crude pyroligneous liquor.
  2. 2. The method for preparing the carbon-based adsorbent according to claim 1, wherein in the step (1), the concentration of the activating agent is 0.05-0.5 mol/L, when the activating agent is a mixed solution of zinc chloride and phosphoric acid, the mixed molar ratio of the zinc chloride to the phosphoric acid is 1:0.25-1:5, the straw is 3-10 g, and the corresponding amount of the activating agent is 50-100 mL.
  3. 3. The method for producing a carbon-based adsorbent according to claim 1, wherein in the step (1), the stirring speed of mixing is 400 to 800rpm, the mixing time is 4 to 8 hours, and the drying temperature is 105 to 150 ℃.
  4. 4. The method for preparing a carbon-based adsorbent according to claim 1, wherein in the step (2), the initial temperature of pyrolysis activation is room temperature, the heating rate is 5-10 ℃ per minute, the pyrolysis temperature is 600-800 ℃, and the heat preservation time is 10-60 minutes.
  5. 5. The method for preparing a carbon-based adsorbent according to claim 1, wherein in the step (2), the inert atmosphere is at least one of nitrogen, argon and helium, and the gas flow rate is 50-100 mL/min.
  6. 6. The method for preparing a carbon-based adsorbent according to claim 1, wherein in the step (3), the biological activated carbon is washed with an acid solution and water, and then dried at 100-150 ℃ to obtain the carbon-based adsorbent for refining and upgrading crude pyroligneous liquor.
  7. 7. The method for preparing a carbon-based adsorbent according to claim 6, wherein the acid solution comprises at least one of hydrochloric acid, nitric acid and sulfuric acid, and the concentration of the acid solution is 0.1-1 mol/L.
  8. 8. A carbon-based adsorbent characterized by being prepared by the preparation method according to any one of claims 1 to 7.
  9. 9. The method of claim 8, wherein the carbon-based adsorbent is used as an adsorbent material for refining and upgrading crude pyroligneous liquor.
  10. 10. The method according to claim 9, wherein the carbon-based adsorbent is used as an adsorbent material for removing phenols in crude pyroligneous liquor.

Description

Preparation method of carbon-based adsorbent for refining and upgrading crude pyroligneous liquor Technical Field The invention relates to the field of biomass resource utilization, in particular to a preparation method of a carbon-based adsorbent for refining and upgrading crude pyroligneous liquor. Background The waste straw is an important biomass resource, has rich reserves and high annual output, and is mainly treated by open burning and landfill modes. These treatment methods result in a great deal of resource waste, environmental pollution, and also create hazards to human health and ecosystems. The pyrolysis technology can efficiently convert waste straws into high-added-value products such as combustible gas, wood vinegar and biochar. The pyroligneous liquor is used as one of main products obtained by pyrolysis of straw, has potential application value in agriculture and industry, and the main components of the pyroligneous liquor comprise moisture, organic acid, phenols, ketones and the like. The organic acid content in the organic matters is highest and is about 50% -70%, wherein the acetic acid content is highest, the organic acid-containing organic matters have the effects of resisting bacteria and adjusting pH, can reduce the surface tension of leaf surfaces, improve the absorption efficiency of nitrogen, phosphorus, potassium and trace elements, and can be widely applied to the fields of industry and agriculture. However, wood vinegar also contains some harmful substances (phenols, polycyclic aromatic hydrocarbons, heavy metals and the like), wherein the phenols are aromatic compounds, account for about 10% -15% of organic substances, have certain biotoxicity, and can inhibit plant growth, destroy soil environment and even threaten human health through food chains if being directly used as liquid fertilizer or pesticide. Based on this, development of efficient pyroligneous liquor refining extraction technology to directionally remove harmful substances therein has become a hot spot of research. The biochar prepared by straw pyrolysis has the problems of small specific surface area, single pore structure, low adsorption selectivity for specific harmful components in wood vinegar, limited adsorption capacity and the like, and needs to be prepared into the activated carbon with the specific pore structure through physical, chemical or biological modification such as acid-base activation so as to improve the adsorption selectivity and the directional removal capacity for the harmful substances in the wood vinegar. For example, literature （H.Y. Zhao, Z.Q. Wang, Y.H. Liang, et al, Adsorptive decontamination of antibiotics from livestock wastewater by using alkaline-modified biochar, Environmental Research 226 (2023) 115676.） utilizes potassium hydroxide to modify biochar, achieving a multiple increase in specific surface area. The literature （D. Xia, F. Tan, C.P. Zhang, et al, ZnCl2-activated biochar from biogas residue facilitates aqueous As(Ⅲ) removal, Applied Surface Science 377 (2016) 361-369.） improves the porosity, specific surface area and adsorption performance of the biochar through zinc chloride modification. The literature （E.G. Griffin, J.M. Nelson, The influence of certain substances on the activity of invertase, Journal of the American Chemical Society 38 (1916) 722-730.） proposes an enzyme immobilization method for the first time, wherein reverse enzymes are adsorbed on activated carbon, the activity is almost unchanged, and the method has high efficiency and is suitable for the selectivity of a complex pollution system. However, these methods have the disadvantages of low adsorption capacity for physical activation, difficulty in synchronously optimizing pore structure and surface chemical properties by a single chemical activator, and great influence on the biological activation method by environment, cost and process, thus limiting the directional design of high-performance activated carbon. Thereby limiting the directional removal capability of phenolic substances in the crude pyroligneous liquor. Based on the method, a modified preparation method of the active carbon with the adjustable pore structure is designed and developed, so that the pyroligneous liquor is converted from a potential pollution source into green production data, a solution with low cost, high efficiency detoxification and resource circulation is provided for high-value utilization of agricultural and forestry waste, and the method is very important for expanding biomass resource utilization. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, in a first aspect of the present invention, a method for preparing a carbon-based adsorbent is provided, which is convenient and efficient, and includes the following steps: (1) Mixing the straw with an activating agent, and drying to obtain a solid phase mixture, wherein the activating agent comprises one of zinc chloride solution, phosph