Preparation method and application of solid adsorption method carbon capture material

Abstract

The preparation method comprises the following steps: S1, preparing raw materials including a carbon source, a chemical activator, diluted hydrochloric acid and deionized water; s2, carrying out carbonization treatment on the raw materials; s3, activating the carbonized raw material, firstly performing chemical activation, and then performing physical activation; s4, cooling and washing the activated material; and S5, drying and crushing the washed material to obtain the solid adsorption method carbon capture material. The specific surface area and the pore structure size of the prepared carbon capture material are adjusted by controlling the impregnation ratio of zinc acetate to ferric chloride and combining the activation temperature and the activation time, so that the prepared solid adsorption method carbon capture material has the optimal adsorption capacity, and more efficient carbon capture can be carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon capture, and in particular to a method for preparing a solid adsorption carbon capture material. Background Art

[0002] Along with the process of industrialization, greenhouse gas emissions, mainly carbon dioxide, have caused global warming, seriously threatening the development of human society. 2 Capture is one of the important technologies to solve the above problems. 2 During capture, carbon capture materials are needed, and carbon capture materials are materials specifically used to capture, adsorb and convert carbon dioxide.

[0003] Most of the existing industrial carbon capture materials are solid adsorption carbon capture materials. The current industrial carbon capture technology mainly relies on the physical adsorption properties of solid adsorption materials (such as activated carbon, zeolite, metal organic framework materials MOFs). Its core mechanism is to adjust the specific surface area of ​​the material (usually 500-3000m 2 / g), pore size distribution (concentrated in the range of 0.3-2nm micropores) and surface chemical functional groups to achieve CO 2 Selective adsorption. However, the existing carbon capture operation mode is to increase CO 2 The capture efficiency of activated carbon is mostly achieved by stacking carbon capture materials, which cannot bring out the best capture efficiency of the carbon capture material, resulting in material waste. Activated carbon is a common solid adsorption material, due to its low cost, easy preparation and regeneration. 2 The capture field has been widely studied, and its CO2 adsorption capacity is relatively low. 2 The selectivity is not high, which is due to the complex pore structure of activated carbon. At present, most of them use physical or chemical methods to increase the porosity and specific surface area of ​​activated carbon, thereby increasing the adsorption capacity of CO2, such as using chemical reagents such as KOH and NaOH for activation, but the pore size matching is insufficient and the precise control of the pore size cannot be achieved. In view of this, this scheme proposes a preparation method of solid adsorption carbon capture material to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a solid adsorption carbon capture material to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing a solid adsorption carbon capture material, the preparation method comprising the following steps:

[0006] S1, preparing raw materials, including a carbon source, a chemical activator, dilute hydrochloric acid and deionized water, wherein the carbon source includes one or more of sawdust, rice husk, coconut shell and polyacrylonitrile, and the chemical activator includes one or more of zinc acetate and ferric chloride;

[0007] S2, pre-treating and carbonizing the raw materials, wherein the pre-treating is drying and crushing the raw materials, and the carbonizing is carbonizing the crushed raw materials;

[0008] Preferably, the carbonization treatment in S2 includes the following steps:

[0009] S201, first drying the prepared raw materials at 60-100° C. until the moisture content in the raw materials is less than 5%;

[0010] S202, using a pulverizer to pulverize the dried raw materials into particles with a diameter less than 0.8 to 1 mm;

[0011] S203, preheating the tubular furnace to 400-800° C., and then introducing nitrogen into the tubular furnace to form an inert atmosphere;

[0012] S204, putting the crushed raw materials into a tubular furnace for carbonization, the carbonization temperature is 450-800° C., and the carbonization time is 1-3 hours.

[0013] S3, activating the raw materials after carbonization: first chemical activation and then physical activation;

[0014] Preferably, the chemical activation of the raw materials in S3 is to first put the carbonized material and the pre-weighed activator into a ball mill and mix them, then put the mixture into a tube furnace, set the chemical temperature at 400-900°C, introduce nitrogen to form an inert gas atmosphere, and then maintain the chemical activity for 1-6 hours to form more porous structures.

[0015] Preferably, the physical activation of the raw materials in S3 is to place the mixture after chemical activation in a tubular furnace with nitrogen or carbon dioxide gas for further physical activation, the physical activation temperature is 500-700°C, and the physical activation time is 4-8h. Physical activation increases porosity and specific surface area, and this step can be used as a continuation of chemical activation to further ensure the adequacy of chemical activation.

[0016] The added amount of the chemical activator accounts for 20% to 50% of the total mass of the carbon source; further preferably, the chemical activator is a mixture of zinc acetate and ferric chloride in a molar ratio of 1:1; the mass ratio of the chemical activator to the carbonized material is 1:3.

[0017] S4, cooling and washing the activated material, wherein the washing is first performed by chemical washing and then by water washing;

[0018] Preferably, the cooling of the material in S4 is to stop the heating for activating the material and allow it to cool naturally to room temperature to avoid structural damage, then use dilute hydrochloric acid to wash the activated material for chemical washing to remove residual activator, and finally use deionized water to rinse multiple times until the pH value of the washing liquid is close to neutral.

[0019] S5, drying and crushing the washed material, and screening through a sieve after crushing to prepare for subsequent performance testing;

[0020] Preferably, the drying and crushing of the washed material in S5 comprises the following steps:

[0021] S501, firstly, the washed material is placed in an oven at 60-80°C for drying for 6-12 hours until the material is completely dry, so as to ensure that the subsequent crushing operation can be carried out after drying;

[0022] S502, putting the dried material into a pulverizer for pulverization;

[0023] S503, using 60 mesh, 100 mesh, 150 mesh and 200 mesh sieves to screen the crushed material;

[0024] S504, the materials crushed by the 60-mesh, 100-mesh, 150-mesh and 200-mesh sieves are collected and marked respectively, and multiple particle sizes are set for comparison, so as to facilitate data aggregation in subsequent performance tests.

[0025] S6, performing application tests, wherein the application tests are carbon capture performance tests and cycle stability tests.

[0026] Preferably, the added amount of the chemical activator accounts for 20% to 50% of the total mass of the raw materials.

[0027] Chemical activators play an important role in improving the pore structure of carbon capture materials. 3 COO 2 ) and ferric chloride (FeCl 3 ), which can effectively adjust and optimize the pore structure of carbon materials, thereby improving their adsorption capacity for carbon dioxide. Chemical activation is to mix and heat the raw materials with chemical activators under high temperature conditions to promote the carbonization and pore formation of carbon materials. The activators participate in the reaction during the carbonization process, generate gas and remove part of the solid carbon, thereby forming a higher specific surface area and richer pore structure;

[0028] Zinc acetate (Zn(CH3 COO 2 ) is a commonly used chemical reagent that can be used as a zinc source. In the carbon capture process, zinc acetate can improve the performance of capture materials by forming zinc-based complexes. These complexes are used to enhance the adsorption capacity of gases, especially the selective adsorption of carbon dioxide.

[0029] Ferric chloride (FeCl 3 ) is a commonly used iron source and can be used as a catalyst or activator to participate in the reaction. In the application of carbon capture, ferric chloride can promote the reaction and improve the reaction activity and adsorption capacity of carbon capture materials. At the same time, ferric chloride can form a synergistic effect with zinc acetate to enhance the overall capture effect.

[0030] Technical effects and advantages of the present invention:

[0031] In the preparation of the solid adsorption carbon capture material of the present invention, zinc acetate and ferric chloride are selected as chemical activators. In this way, the specific surface area and pore structure size of the prepared carbon capture material are adjusted by the addition amount of zinc acetate and ferric chloride, combined with the activation temperature and activation time. After application testing, the solid adsorption carbon capture material prepared in this way has the best adsorption capacity, thereby enabling the carbon capture equipment produced by this scheme to perform more efficient carbon capture. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the operation flow of the preparation method of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example

[0035] (1) First, the sawdust is dried at 100° C. until the moisture content in the raw material is less than 5%. After drying, the subsequent crushing work can be more convenient; the dried raw material is crushed into particles with a diameter less than 0.8 to 1 mm using a crusher;

[0036] (2) Preheat the tube furnace to 450°C, and then introduce nitrogen into the tube furnace to form an inert atmosphere;

[0037] (3) The raw materials crushed in step (1) are placed in a tubular furnace for carbonization for 1 hour.

[0038] (4) Activating the carbonized material in step (3), first chemically activating and then physically activating; wherein the chemical activation is to first put the carbonized material and the pre-weighed activator into a ball mill for mixing, and during the mixing process, continuously stirring to ensure uniform mixing, and then putting the mixture into a tubular furnace, setting the temperature at 450°C, introducing nitrogen to form an inert gas atmosphere, and then maintaining the chemical activation for 4 hours to form a more porous structure; the physical activation is to continue to place the chemically activated mixture in a tubular furnace filled with nitrogen and continue to heat it, the heating temperature is set to 600°C, and the heating time is 5 hours.

[0039] (5) After physical activation, stop heating the material and allow it to cool naturally to room temperature. Then, use dilute hydrochloric acid to wash the activated material for chemical washing to remove the residual activator. Finally, use deionized water to rinse it multiple times until the pH value of the washing solution is close to neutral.

[0040] (6) The washed material is placed in an oven at 80° C. to dry until the material is completely dry, and the dried material is placed in a pulverizer for crushing; the crushed material is screened using 60-mesh, 100-mesh, 150-mesh and 200-mesh sieves respectively; and the crushed material is collected and marked to obtain a carbon capture material.

[0041] The carbon capture material was subjected to application test, which was a carbon capture performance test and a cycle stability test. : 0.1 g of the prepared carbon capture material powder (150 mesh) was placed in the adsorption device; the gas flow rate was set to 100 mL / min, and the test temperature was set to 25 °C and the pressure was set to 101.3 kPa; CO 2 The gas is injected into the device to start the adsorption process, and the gas concentration changes are monitored using a gas chromatograph or infrared gas analyzer to record the CO before and after adsorption. 2 Gas concentration; Calculate the CO of the material based on the gas concentration change and flow rate 2 Adsorption capacity.

[0042] It should be noted that the calculation includes the calculation of CO 2 The amount of inflow is calculated as follows:

[0043] C 入 =(C 0 -C f )×Q×t×conversion factor (1);

[0044] Among them, C 0 Indicates CO 2 Initial concentration of gas injection, C f When the adsorption reaches equilibrium, the CO flowing out of the system is measured. 2Gas concentration, t represents the time from gas injection to adsorption stabilization, Q represents the gas flow rate, and the conversion factor is expressed as follows: if the flow rate is expressed in L / min and the concentration is expressed in mg / L, then the inflowing CO 2 The unit of quantity is mg.

[0045] Under the activation conditions of the above examples, the type of activator and the mass ratio of the carbonized material to the activator (impregnation ratio) were studied to determine the CO 2 The effect of adsorption amount is shown in Table 1 below;

[0046] Table 1 CO2 capture of carbon capture materials after modification with different impregnation ratios 2 Adsorption Comparison Table

[0047]

[0048] From Table 1, we can see that the use of Zn(CH 3 COO 2 +FeCl 3 As a mixed activator, the carbon capture material CO was obtained when the mass ratio of the activator to the carbonized material was 1:3. 2 The adsorption capacity is the best.

[0049] Based on the reaction conditions of Example 6 in Table 1 [the impregnation ratio (using Zn(CH 3 COO 2 +FeCl 3 1:3)] and chemical activation time of 4h to study the CO2 capture effect of carbon capture materials modified with different chemical activation temperatures. 2 The adsorption amount is shown in Table 2 below;

[0050] Table 2 CO2 of carbon capture materials modified by different chemical activation temperatures 2 Adsorption Comparison Table

[0051]

[0052]

[0053] Set the impregnation ratio (using Zn(CH 3 COO 2 +FeCl 3 1:3) and chemical activation temperature 600℃, CO of carbon capture materials after modification with different activation times 2 The adsorption amount is shown in Table 3 below;

[0054] Table 3 CO2 removal of carbon capture materials after modification with different chemical activation times 2 Adsorption Comparison Table

[0055]

[0056] Combining the above Tables 1, 2 and 3, it can be seen that the optimal impregnation ratio of carbon capture material is Zn(CH 3 COO 2 +FeCl 3 1:3, the optimal chemical activation temperature range is 600℃, and the optimal chemical activation time range is 6h.

[0057] Set the impregnation ratio (using Zn(CH 3 COO 2 +FeCl 3 1:3) and chemical activation temperature of 600℃, chemical activation time of 6h, CO of carbon capture materials modified at different physical activation temperatures 2 The adsorption amount is shown in Table 4 below;

[0058] Table 4 CO2 of carbon capture materials modified by different physical activation temperatures 2 Adsorption Comparison Table

[0059]

[0060]

[0061] Set the impregnation ratio (using Zn(CH 3 COO 2 +FeCl 3 1:3) and chemical activation temperature of 600℃, chemical activation time of 6h, physical activation temperature of 600℃, CO of carbon capture materials after modification with different physical activation time 2 The adsorption amount is shown in Table 4 below;

[0062] Table 5 CO2 removal of carbon capture materials after modification with different physical activation times 2 Adsorption Comparison Table

[0063] Example Activation time (h) <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Total pore volume (cm 2 / g)]]> <![CDATA[CO 2 Adsorption capacity (mmol / g)]]> Cycle adsorption loss rate Embodiment 25 4 2619.42 0.63 2.87 22.64％ Embodiment 26 5 3174.33 0.79 3.19 5.51％ Embodiment 17 6 3748.02 0.96 3.70 3.66％ Embodiment 27 7 3952.31 0.98 3.84 3.21％ Embodiment 28 8 3306.17 0.84 3.31 5.22％

[0064] Combining the above Tables 1, 2, 3, 4 and 5, it can be seen that the optimal impregnation ratio of the carbon capture material is Zn(CH 3 COO 2 +FeCl 3 1:3, the optimal chemical activation temperature range is 600℃, the optimal chemical activation time range is 6h. The physical activation temperature is 600℃, and the physical activation time is 7h.

[0065] The cyclic stability test includes repeated adsorption tests and desorption experiments;

[0066] Repeated adsorption is the process of performing multiple CO adsorptions under the same conditions. 2Adsorption experiments were conducted to evaluate the cyclic stability of the materials. The adsorption loss rate of the carbon capture materials after 5 cycles-analysis is shown in Tables 1-5.

[0067] The desorption experiment is to conduct CO 2 The desorption experiment is to observe whether the adsorption capacity of the material remains stable. The analytical experiment only requires high-temperature desorption of the activated carbon at 100 degrees Celsius for 6 hours.

[0068] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a solid adsorption carbon capture material, characterized in that: The preparation method comprises the following steps: S1, preparing raw materials: a carbon source, a chemical activator, dilute hydrochloric acid and deionized water; the carbon source comprises one or more of sawdust, rice husk, coconut shell and polyacrylonitrile; the chemical activator comprises one or a mixture of zinc acetate and ferric chloride; S2, drying and crushing the carbon source, and carbonizing the crushed carbon source; S3, activating the carbonized material, first chemically activating it, and then physically activating it; specifically, putting the carbonized material and the activator into a ball mill and mixing them, and then putting the mixture into a tube furnace, setting the temperature of chemical activation at 400-900°C, introducing nitrogen to form an inert gas atmosphere, and then maintaining the chemical activation for 1-6 hours; placing the chemically activated material in a tube furnace with nitrogen or carbon dioxide gas for physical activation, the physical activation temperature is 500-700°C, and the physical activation time is 4-8 hours; S4, cooling and washing the activated material, first using a dilute hydrochloric acid solution for chemical washing, and then washing with water; S5, drying and crushing the washed material, and screening the crushed material through a sieve to obtain a solid adsorption carbon capture material.

2. The method for preparing a solid adsorption carbon capture material according to claim 1, characterized in that: The added amount of the chemical activator accounts for 20% to 50% of the total mass of the carbon source.

3. The method for preparing a solid adsorption carbon capture material according to claim 1, characterized in that: The specific operation of S2 is: S201, first drying the prepared carbon source at 60-100° C. until the moisture content in the raw material is less than 5%; S202, using a pulverizer to pulverize the dried raw materials into particles with a diameter less than 0.8 to 1 mm; S203, preheating the tube furnace to 400-800° C., and then introducing nitrogen into the tube furnace to form an inert atmosphere; S204, putting the crushed raw materials into a tubular furnace for carbonization, and the carbonization time is 1 to 3 hours.

4. The method for preparing a solid adsorption carbon capture material according to claim 1, characterized in that: The chemical activator is obtained by mixing zinc acetate and ferric chloride in a molar ratio of 1:1; the mass ratio of the chemical activator to the carbonized material is 1:

3.

5. The method for preparing a solid adsorption carbon capture material according to claim 1, characterized in that: The cooling of the material in S4 is to stop the heating for activating the material, allow it to cool naturally to room temperature, then use dilute hydrochloric acid to wash the activated material to remove the residual activator, and finally use deionized water to rinse it multiple times until the pH value of the washing liquid is close to neutral.

6. The method for preparing a solid adsorption carbon capture material according to claim 1, characterized in that: The specific steps of drying and crushing the washed material in S5 are as follows: S501, firstly, drying the washed material in an oven at 60-80°C for 6-12 hours until the material is completely dry; S502, putting the dried material into a pulverizer for pulverization; S503, using screens to screen and mark the crushed materials.

7. A solid adsorption carbon capture material prepared according to the method according to any one of claims 1 to 6.

8. Use of the solid adsorption carbon capture material prepared according to the method according to any one of claims 1 to 6 in CO2 capture and adsorption.

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