A porous activated carbon prepared using balsa wood material, its preparation method and application

Abstract

This invention discloses a porous activated carbon prepared using balsa wood material, its preparation method, and its application. The porous activated carbon has a pore diameter of 0.4 nm to 400 nm, and the pore volume ratio of micropores (0.4 nm to 2 nm), mesopores (2 nm to 50 nm), and macropores (50 nm to 400 nm) is greater than 30%. The specific surface area of ​​the porous activated carbon is 500 to 700 m² / g. It has an adsorption rate of 130% to 145% for carbon tetrachloride, exhibiting excellent adsorption performance.

Description

Technical Field

[0001] This invention belongs to the field of adsorption materials technology, specifically relating to a porous activated carbon prepared using balsa wood material, its preparation method, and its application. Background Technology

[0002] Carbon tetrachloride is a common chlorinated volatile organic compound (VOC) widely used as a solvent in industry, agriculture, and pharmaceutical production. Carbon tetrachloride released into the ambient air can enter the human body through inhalation or skin absorption, causing damage to the liver, kidneys, and nervous system, and may even induce cancer. Carbon tetrachloride is also ecotoxicous and difficult to degrade, causing long-term harm to water bodies and soil. Therefore, the removal and recovery of carbon tetrachloride gas from the environment and from industrial waste has become an important issue in environmental governance.

[0003] In carbon tetrachloride removal and recovery processes, activated carbon adsorption is the most widely used and convenient technology. The adsorption capacity of activated carbon materials for carbon tetrachloride molecules also reflects their adsorption performance for other chlorinated volatile organic compounds. However, current processes for increasing the specific surface area of ​​materials are complex and involve the use of large amounts of corrosive strong acids and bases. Furthermore, the current technology's adsorption capacity for carbon tetrachloride needs further improvement. Therefore, developing activated carbon materials with simple processes and high carbon tetrachloride adsorption rates remains a challenge in existing technologies. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing multi-level porous activated carbon using balsa wood material. The prepared activated carbon material can achieve efficient adsorption of carbon tetrachloride and has excellent adsorption performance.

[0005] The objective of this invention is achieved through the following technical solution.

[0006] A porous activated carbon prepared using balsa wood material, wherein the pore diameter of the obtained porous activated carbon is 0.4 nm to 400 nm.

[0007] The porous activated carbon has a pore volume ratio of more than 30% for micropores (0.4 nm to 2 nm), mesopores (2 nm to 50 nm), and macropores (50 nm to 400 nm).

[0008] The specific surface area of ​​the porous activated carbon is 500~700 m² / g.

[0009] A method for preparing porous activated carbon using balsa wood material, employing sodium cyclohexanesulfonate as a pore-forming agent.

[0010] A method for preparing porous activated carbon using balsa wood material, the preparation method specifically includes the following steps:

[0011] S1, Preprocessing

[0012] Balsa wood is cut into blocks, preheated at 220℃~260℃, cooled, crushed, and sieved to obtain preheated balsa wood powder.

[0013] S2, Mixing and Pyrolysis

[0014] Preheated balsa wood powder A, sodium cyclohexanesulfonate and water are mixed in a weight ratio of 1:(0.2~0.6):(3~6), stirred and dried, heated to 750℃~800℃ in an inert atmosphere and cooled to obtain primary carbonized material.

[0015] S3, Chemical Activation and Post-treatment

[0016] The primary carbonized material was soaked in sodium hydroxide solution, stirred, filtered, and washed with water until neutral. Then it was soaked in hydrochloric acid solution, filtered, washed with water until neutral, and dried to obtain porous activated carbon material.

[0017] In step S2, the inert gas is either nitrogen or argon.

[0018] In step S2, the heating rate is 2°C to 5°C per minute.

[0019] In step S3, the concentration of the hydrochloric acid solution used for soaking the carbon material is 0.1 mol / L ~ 1 mol / L.

[0020] The porous activated carbon described above or the porous activated carbon prepared by the above preparation method is applied to carbon tetrachloride adsorption applications.

[0021] The porous activated carbon has an adsorption rate of 130% to 145% for carbon tetrachloride.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The activated carbon material prepared by this invention has an adsorption capacity of over 130% for carbon tetrachloride when the specific surface area is no greater than 700 m² / g.

[0024] The activated carbon material prepared by this invention has a multi-level pore structure, containing abundant micropores, mesopores, and macropores, with each of the micropore, mesopore, and macropore volumes accounting for no less than 30%. The resulting multi-level pore structure, combining multiple pore sizes, significantly improves the adsorption effect. Attached Figure Description

[0025] Figure 1Scanning electron microscope (SEM) image (a) and elemental energy dispersive spectroscopy (EDS) data (b) of the carbon material obtained in Example 1;

[0026] Figure 2 The graph shows the change in specific surface area and pore volume of the carbon material obtained in Example 1 as a function of pore size.

[0027] Figure 3 Data on the carbon tetrachloride adsorption rate of the carbon material obtained in Example 1.

[0028] Figure 4 Scanning electron microscope image (a) and elemental energy dispersive spectroscopy (EDS) data (b) of the carbon material obtained in Example 2;

[0029] Figure 5 The graph shows the change in specific surface area and pore volume of the carbon material obtained in Example 2 as a function of pore size.

[0030] Figure 6 Data on the carbon tetrachloride adsorption rate of the carbon material obtained in Example 2.

[0031] Figure 7 Scanning electron microscope image (a) and elemental energy dispersive spectroscopy (EDS) data (b) of the carbon material obtained in Example 3;

[0032] Figure 8 The graph shows the change in specific surface area and pore volume of the carbon material obtained in Example 3 as a function of pore size.

[0033] Figure 9 Data on the carbon tetrachloride adsorption rate of the carbon material obtained in Example 3. Detailed Implementation

[0034] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0035] The following examples involve the following pharmaceutical products:

[0036] Sodium cyclohexanesulfonate: 99%, Shanghai Maclean Biochemical Technology Co., Ltd.

[0037] Hydrochloric acid: 35-38% by mass, Tianjin Fengchuan Chemical Reagent Technology Co., Ltd.

[0038] Sodium hydroxide: mass percentage >96%, Tianjin Hengxing Chemical Reagent Manufacturing Co., Ltd. Example

[0039] A method for preparing porous carbon using balsa wood material includes the following steps:

[0040] 1) Cut 2.5-year-old balsa wood from Indonesia into blocks approximately 2 cm long, wide, and high. Then place the balsa wood blocks in an oven at 240°C. o Preheat the oven at C for 6 hours. After preheating, allow the oven to cool naturally to 60°C. o At step C, the preheated balsa wood material is placed into a pulverizer and crushed, then sieved through a 40-mesh sieve to obtain preheated balsa wood powder A.

[0041] 2) Add preheated balsa wood powder A and sodium cyclohexanesulfonate to water and mechanically stir for 3 hours. The weight ratio of preheated balsa wood powder A, sodium cyclohexanesulfonate, and water is 1:(0.5):4. After stirring, place the mixture at 80°C. o Drying in oven C yields mixed raw material B. Mixed raw material B is then placed in an argon atmosphere-protected heating furnace at a speed of 3 [units per minute]. o Heating to 800°C at a heating rate of C o C, heat-treated for 2 hours. After heat treatment, cooled to room temperature to obtain primary carbonized material C.

[0042] 3) The obtained primary carbonized material C was soaked and stirred in a 1 mol / L sodium hydroxide solution for 24 hours, then filtered. The filtered carbon material was washed with deionized water until the washing solution was neutral. Then, the washed carbon material was soaked and stirred in a 0.5 mol / L hydrochloric acid solution for 24 hours, followed by filtration. The powder material after the liquid was removed was washed with deionized water until the washing solution was neutral. Finally, the obtained powder material was heated at 90°C. o The product, multi-level porous activated carbon material, is obtained by drying in a forced-air drying oven.

[0043] The morphology of the obtained material was characterized using scanning electron microscopy, and the elemental composition was analyzed using energy dispersive spectroscopy. The results are as follows: Figure 1 As shown, the obtained material has a granular morphology with a micron-scale pore structure on its surface. The main component of the obtained material is carbon (symbol: C), accounting for 93.37% by mass. Other components, including oxygen (O), sulfur (S), nitrogen (N), and sodium (Na), may be related to the pore-forming agent sodium cyclohexanesulfonate. The surface area and pore size distribution of the obtained carbon material were tested using a specific surface area and pore size analyzer, and the results are shown below. Figure 2 As shown. From Figure 2 The result shows that the specific surface area of ​​the obtained carbon material is 522.69 cm². 2 / g; the pore size of the obtained carbon material is present in the range of 0.6 nm to 400 nm; within the pore size range of 0.4 nm to 400 nm, the micropore volume accounts for 35.64%; the mesopore volume accounts for 32.49%; and the macropore volume accounts for 31.87%. Carbon tetrachloride adsorption tests were performed on the obtained activated carbon material with a hierarchical porous structure, and the results are as follows: Figure 3 As shown, the carbon tetrachloride adsorption rate of the obtained porous activated carbon material is 138.2%. Example

[0044] A method for preparing porous carbon using balsa wood material includes the following steps:

[0045] 1) Cut 3-year-old balsa wood from Papua New Guinea into blocks approximately 2 cm long, wide, and high. Then place the balsa wood blocks in an oven at 260°C. o Preheat the oven at C for 8 hours. After preheating, allow the oven to cool naturally to 60°C. o At step C, the preheated balsa wood material is placed into a pulverizer and crushed, then sieved through a 40-mesh sieve to obtain preheated balsa wood powder A.

[0046] 2) Add preheated balsa wood powder A and sodium cyclohexanesulfonate to water and mechanically stir for 6 hours. The weight ratio of preheated balsa wood powder A, sodium cyclohexanesulfonate, and water is 1:1:6. The mixed material is then placed in an 80°C container. o Drying in oven C yields mixed raw material B. Mixed raw material B is then placed in a nitrogen-atmosphere protected heating furnace at a speed of 2 [units per minute]. o The heating rate of C is increased to 850. o C, heat-treated for 4 hours. After heat treatment, cooled to room temperature to obtain primary carbonized material C.

[0047] 3) The obtained primary carbonized material C was soaked and stirred in a 2 mol / L sodium hydroxide solution for 12 hours, then filtered. The filtered carbon material was washed with deionized water until the washing solution was neutral. Then, the washed carbon material was soaked and stirred in a 0.1 mol / L hydrochloric acid solution for 48 hours, followed by filtration. The powder material after the liquid was removed was washed with deionized water until the washing solution was neutral. Finally, the obtained powder material was heated at 110 °C. o The product, multi-level porous activated carbon material, is obtained by drying in a forced-air drying oven.

[0048] The morphology of the obtained material was characterized using scanning electron microscopy, and the elemental composition was analyzed using energy dispersive spectroscopy. The results are as follows: Figure 4As shown, the obtained material has a granular morphology with a micron-scale pore structure on its surface, revealing the porous structure of wood. The main component of the obtained material is carbon (symbol: C), with a mass percentage >90%. Other components, such as oxygen (O), sulfur (S), nitrogen (N), and sodium (Na), may be related to the pore-forming agent sodium cyclohexanesulfonate. The surface area and pore size distribution of the obtained carbon material were tested using a specific surface area and pore size analyzer, and the results are as follows. Figure 5 As shown. From Figure 5 The specific surface area of ​​the obtained carbon material is 674.86 cm². 2 / g, the pore size of the obtained carbon material is present in the range of 0.6 nm to 400 nm; within the pore size range of 0.4 nm to 400 nm, the micropore volume accounts for 34.76%; the mesopore volume accounts for 34.34%; and the macropore volume accounts for 30.90%. Carbon tetrachloride adsorption tests were performed on the obtained carbon material with a hierarchical porous structure, and the results are as follows. Figure 6 As shown, the carbon tetrachloride adsorption rate of the material is 144.5%. Example

[0049] A method for preparing porous carbon using balsa wood material includes the following steps:

[0050] 1) Cut 2-year-old basa wood from Indonesia into blocks approximately 2 cm long, wide, and high. Then place the blocks in an oven at 220°C. o Preheat the oven at C for 4 hours. After preheating, allow the oven to cool naturally to 60°C. o At step C, the preheated balsa wood material is placed into a pulverizer and crushed, then sieved through a 40-mesh sieve to obtain preheated balsa wood powder A.

[0051] 2) Add preheated balsa wood powder A and sodium cyclohexanesulfonate to water and mechanically stir for 6 hours. The weight ratio of preheated balsa wood powder A, sodium cyclohexanesulfonate, and water is 1:0.3:3. After stirring, place the mixture at 80°C. o Drying in oven C yields mixed raw material B. Mixed raw material B is then placed in a nitrogen-atmosphere protected heating furnace at a speed of 5 [units per minute]. o Heating to 750°C at a rate of C o C, heat-treated for 1 hour. After heat treatment, cooled to room temperature to obtain primary carbonized material C.

[0052] 3) The obtained primary carbonized material C was soaked and stirred in a 0.5 mol / L sodium hydroxide solution for 48 hours, then filtered. The filtered carbon material was washed with deionized water until the washing solution was neutral. Then, the washed carbon material was soaked and stirred in a 1 mol / L hydrochloric acid solution for 12 hours, followed by filtration. The powder material after the liquid was removed was washed with deionized water until the washing solution was neutral. Finally, the obtained powder material was heated to 60 °C. o The product, multi-level porous activated carbon material, is obtained by drying in a forced-air drying oven.

[0053] The morphology of the obtained material was characterized using scanning electron microscopy, and the elemental composition was analyzed using energy dispersive spectroscopy. The results are as follows: Figure 7 As shown, the obtained material has a granular morphology with a micron-scale pore structure on its surface. The main component of the obtained material is carbon (symbol: C), with a mass percentage >90%. The other components, including oxygen (O), sulfur (S), nitrogen (N), and sodium (Na), may be related to the pore-forming agent sodium cyclohexanesulfonate. The surface area and pore size distribution of the obtained carbon material were tested using a specific surface area and pore size analyzer, and the results are shown below. Figure 8 As shown. From Figure 8 The result shows that the specific surface area of ​​the obtained carbon material is 501.48 cm². 2 / g, the pore size of the obtained carbon material is present in the range of 0.6 nm to 400 nm; within the pore size range of 0.4 nm to 400 nm, the micropore volume accounts for 36.72%; the mesopore volume accounts for 33.02%; and the macropore volume accounts for 30.26%. Carbon tetrachloride adsorption tests were performed on the obtained carbon material with a hierarchical porous structure, and the results are as follows: Figure 9 As shown, the adsorption rate of carbon tetrachloride in the material is 133.7%.

Claims

1. A method for preparing a porous activated carbon using Bashan wood material, characterized by, In the formula, R represents a hydrogen atom or a C1-C4 alkyl group, and n represents an integer of 1 to 3. The preparation method specifically comprises the following steps: S1, pretreatment Basswood timber is cut into blocks, preheated at 220-260 DEG C, cooled, crushed, sieved, and basswood powder is obtained; S2, mixing and pyrolysis The preheated basswood powder, sodium cyclohexane sulfamate and water are mixed at a weight ratio of 1:(0.2-0.6):(3-6), stirred, dried, heated to 750-800 DEG C in an inert atmosphere, and cooled to obtain primary carbonized material. The primary carbonized material is soaked with sodium hydroxide solution, stirred, filtered, washed with water until neutral, soaked with hydrochloric acid solution, filtered, washed with water until neutral, and dried to obtain a porous activated carbon material, wherein the porous activated carbon has a pore diameter of 0.4nm to 400nm, and the pore volume ratio of micropores with a pore diameter of 0.4nm to 2nm, mesopores with a pore diameter of 2nm to 50nm, and macropores with a pore diameter of 50nm to 400nm is greater than 30%, and the specific surface area of the porous activated carbon is 500 to 700m 2 / g.

2. The method of claim 1, wherein the porous activated carbon is prepared using a Balsa wood material. S3, chemical activation and post-treatment 3. The method of claim 1, wherein the porous activated carbon is prepared using a Balsa wood material. In the step S2, the inert atmosphere is one of nitrogen or argon.

4. The method of claim 1, wherein the porous activated carbon is prepared using a Balsa wood material. In the step S2, the temperature rising rate is 2-5 DEG C per minute.

5. Use of the porous activated carbon prepared by the method according to any one of claims 1 to 4 in carbon tetrachloride adsorption, characterized in that, In the step S3, the hydrochloric acid solution used for carbon material immersion has a concentration of 0.1-1 mol / L. The porous activated carbon has a carbon tetrachloride adsorption rate of 133.7-145%.

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