Preparation method of reproducible solid amine material for adsorbing CNCl

Abstract

The invention relates to the field of adsorbent preparation, in particular to a preparation method of a reproducible solid amine material for adsorbing CNCl. Comprising the following steps: (1) firstly, pretreating a carrier MCM-41 or SBA-15; (2) weighing organic amine, dissolving the organic amine into absolute ethyl alcohol, and uniformly mixing; (3) weighing the carrier pretreated in the step (1), adding into the mixed solution in the step (2), and stirring at 40 DEG C for 8 hours; (4) after the stirring is completed, drying the mixture in a drying oven, and obtaining a solid amine material after the absolute ethyl alcohol is completely evaporated; no other heavy metal pollutants are introduced in the preparation process, the technology is simple, reproducible adsorption and desorption can be carried out for five times, and technical support can be provided for design of a reproducible CNCl device.

Description

Technical Field

[0001] The invention relates to the field of adsorbent preparation, and in particular to a method for preparing a regenerable solid amine material for adsorbing CNCl. Background Art

[0002] SBA-15 is usually used for the regenerative adsorption of CO2. Amine-grafted mesoporous materials are the main factors in the CO2 capture performance. Related studies have investigated the effects of SBA-15 with different boron loadings on the CO2 adsorption capacity. It was found that the dynamic capacity of CO2 showed a volcano-shaped curve with the change of boron loading. Hao Yuan and Peng Li used BTESE (1,2-bis (triethoxysilyl)) ethane as the silicon source, impregnated SBA-15 with polyethyleneimine (PEI) and diethylenetriamine (DETA), and used the type of amine (PEI and DETA), the loading amount of amine (0%-50%) and the temperature (20-120°C) as parameters. The regenerative adsorption of CO2 was studied. It was found that the DETA-modified adsorbent had a higher amine dispersion, and the PEI-modified adsorbent performed better in thermal stability, adsorption capacity and adsorption kinetics. However, both CNCl and CO2 are acidic gases, and organic amines can achieve regenerative adsorption of CNCl. The existing protective material for CNCl is impregnated activated carbon, which contains various metal oxides and achieves a single protection by chemically reacting with CNCl, and cannot be regenerated in situ. Therefore, it is necessary to invent a material that can regenerate CNCl to provide technical support for the regenerative adsorption system. Summary of the invention

[0003] The present invention solves the technical problem that the existing CNCl adsorption materials cannot realize the regenerative adsorption of CNCl, cannot realize desorption and multiple regeneration, and provides a preparation method of a regenerative solid amine material for adsorbing CNCl. The preparation process of the prepared material is simple, and the material can realize the in-situ regeneration characteristic of CNCl adsorption.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing a regenerable solid amine material for adsorbing CNCl, comprising the following steps:

[0005] (1) First, the carrier MCM-41 or SBA-15 is pretreated;

[0006] (2) weighing an organic amine, dissolving it in anhydrous ethanol, and mixing it evenly;

[0007] (3) Weigh the carrier pretreated in step (1) and add it to the mixed solution in step (2), and stir at 40° C. for 8 h;

[0008] (4) After the stirring is completed, the mixture is placed in a drying oven to dry, and after the anhydrous ethanol is completely evaporated, a solid amine material is obtained.

[0009] As a further limitation of the technical solution of the present invention, the pretreatment method in step (1) is: placing the carrier in a muffle furnace and calcining it at a temperature of 400° C. for 4 hours.

[0010] As a further limitation of the technical solution of the present invention, the mixed solution in step (2) is stirred in a magnetic stirrer for 30 minutes.

[0011] As a further limitation of the technical solution of the present invention, the organic amine in step (2) is diethylenetriamine, triethylenetetramine or tetraethylenepentamine.

[0012] As a further limitation of the technical solution of the present invention, during the stirring process in step (3), the container is sealed.

[0013] As a further limitation of the technical solution of the present invention, the loading amount of the organic amine in the mixture in step (4) is 10 wt %-30 wt %.

[0014] As a further limitation of the technical solution of the present invention, the drying condition in the drying oven in step (4) is: drying at 60° C. overnight.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The material used in the present invention can realize the regenerative adsorption of CNCl by physical adsorption and weak chemical adsorption.

[0017] 2. The method of the present invention is green and energy-saving, and the process steps used are simple.

[0018] 3. The evaluation device of the present invention is simple to operate and highly practical, and can provide reference for subsequent renewable air purification devices.

[0019] 4. No other heavy metal pollutants are introduced during the preparation process of the adsorption material of the present invention. The present invention can solve the problems of metal pollution and renewability at the same time. The technology is simple and can perform renewable adsorption and desorption 5 times, which can provide technical support for the design of renewable CNCl devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The effect of carrier type on CO2 adsorption performance.

[0021] Figure 2 Effect of organic amine types on CO2 adsorption performance.

[0022] Figure 3 Effect of organic amine loading on CO2 adsorption performance DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with specific embodiments.

[0024] Example

[0025] The materials used in this example are: diethylenetriamine, triethylenetetramine, tetraethylenepentamine, MCM-41, SBA-15, deionized water, N2 / CO2, anhydrous ethanol, toluene, etc. The instruments used in this experiment are: a heat-collecting constant temperature magnetic stirrer, a blast drying oven, a high-temperature fixed bed, a gas analyzer, a muffle furnace, an electronic balance, etc.

[0026] The organic amine solid adsorbent was prepared by physical impregnation method: first, the carrier (MCM-41, SBA-15) was pretreated, and the carrier was placed in a muffle furnace and calcined at 400℃ for 4h to remove the impurity gas pre-adsorbed by MCM-41 and SBA-15 in the air. Then, a certain mass of organic amine (diethylenetriamine, triethylenetetramine, tetraethylenepentamine) was weighed and dissolved in a beaker containing 15mL of anhydrous ethanol, and placed in a magnetic stirrer for 30min to mix evenly, and a certain amount of pretreated carrier was weighed and added to the mixed solution, and continued to stir at 40℃ for 8h. During the stirring process, the container was sealed to prevent the amine from being oxidized by contact with air. After stirring, the mixture was placed in a drying oven at 60℃ and dried overnight. After all the anhydrous ethanol was evaporated, a solid amine adsorbent was obtained.

[0027] The adsorbent performance evaluation method is as follows:

[0028] Since CO2 is non-toxic, CO2 is first used to evaluate the reproducible adsorption performance of the material, and then CNCl is used for evaluation.

[0029] First, the CO2 adsorption and desorption process of the adsorbent was tested in the built fixed bed. During the measurement, a layer of quartz wool was filled at the bottom of the quartz reaction tube with an inner diameter of 1 cm to support the sample, and 0.3g of adsorbent was added. Before the adsorbent adsorbed CO2, it was degassed at 80℃ for 15min under 100mL / min N2 to remove the pre-adsorbed gas. During the analysis, after the fixed bed was cooled to the required adsorption temperature, the mixed gas (20vol%CO2+80vol%N2) was introduced into the reactor at a flow rate of 100mL / min. The outlet CO2 gas concentration was measured by a gas analyzer, and the CO2 adsorption amount was calculated based on the change in the outlet gas concentration. When the outlet CO2 concentration reached 95% of the inlet concentration, it was considered to have reached adsorption equilibrium. The adsorption penetration curve was drawn with time t as the horizontal axis and the outlet CO2 molar flow rate as the vertical axis. The adsorption capacity of the adsorbent was calculated by the integral area of ​​the penetration curve, the inlet CO2 concentration, the flow rate, the adsorption time and the mass of the adsorbent.

[0030] The integral equation of CO2 adsorption breakthrough curve is as follows:

[0031]

[0032] Where QS is the saturated adsorption capacity of the adsorbent, mmol·g-1; F is the CO2 inlet flow rate, mL / min; m is the mass of the adsorbent, g; C0 and C represent the inlet concentration and outlet concentration of CO2, mmol / L, respectively. The cyclicity of the adsorbent was determined by continuous adsorption-regeneration experiments. The adsorption time of each cycle was 30 min, the regeneration time was 15 min, and the other conditions were the same as above. The cycle process was repeated 5 times.

[0033] Experimental verification results:

[0034] To verify the effect of carrier type on CO2 adsorption performance, the CO2 adsorption performance of 30wt% diethylenetriamine / MCM-41 and diethylenetriamine / SBA-15 solid amine adsorbents at 50℃ and desorption performance at 80℃ were tested on a fixed bed. The results are shown in Figure 1 It can be seen that the solid amine adsorbent with SBA-15 as the carrier has a higher CO2 adsorption capacity and better cycle stability.

[0035] To verify the effect of organic amine types on CO2 adsorption performance, the CO2 adsorption performance of solid amine adsorbents with a loading of 30 wt% diethylenetriamine / SBA-15, triethylenetetramine / SBA-15 and tetraethylenepentamine / SBA-15 at 50°C and the desorption performance at 80°C were tested on a fixed bed. The results are as follows Figure 2 It can be seen that the solid amine adsorbent loaded with tetraethylenepentamine has a higher CO2 adsorption capacity and better cycle stability, and the average CO2 adsorption capacity is the highest.

[0036] To verify the effect of organic amine loading on CO2 adsorption performance, the CO2 adsorption performance of tetraethylenepentamine / SBA-15 solid amine adsorbent with a loading of 10-30wt% at 50°C and the desorption performance at 80°C were tested on a fixed bed. The results are as follows Figure 3 As shown. It can be seen that the 30wt% tetraethylenepentamine / SBA-15 solid amine adsorbent has a higher CO2 adsorption capacity and better cycle stability, and the average CO2 adsorption capacity is the highest. Therefore, the focus is on selecting 30wt% tetraethylenepentamine / SBA-15 as the adsorbent to further optimize the CNCl regeneration experimental conditions of the material.

[0037] CNCl real toxicity test evaluation:

[0038] To evaluate the renewability of the adsorbent material CNCl, the adsorption experiment of the material was carried out according to the national standard GJB1468A-2007 Appendix H. The desorption process was to connect the adsorbed stainless steel measuring tube to the vacuum pump and air generator for vacuum and small flow purge for desorption. The specific reference application number is 202210568782.3 authorized patent "A renewable adsorption material evaluation device and its evaluation method"

[0039] The evaluation results are as follows:

[0040] Table 1 Evaluation of the regenerative adsorption performance of CNCl by organic amines

[0041]

[0042] From Table 1 above, it can be seen that 30wt% tetraethylenepentamine / SBA-15 has relatively regenerative adsorption performance for CNCl. And the single adsorption time is long, which is expected to become a candidate material for regenerative adsorption performance of CNCl.

Claims

1. A method for preparing a regenerable solid amine material for adsorbing CNCl, characterized in that: The following steps are involved: (1) First, pretreat the carrier MCM-41 or SBA-15; (2) Weigh the organic amine, dissolve it in anhydrous ethanol, and mix well; (3) Weigh the carrier pretreated in step (1) and add it to the mixed solution in step (2), and stir at 40°C for 8 hours; (4) After stirring, the mixture is placed in a drying oven to dry, and after all the anhydrous ethanol is evaporated, a solid amine material is obtained.

2. The method for preparing a regenerable solid amine material for adsorbing CNCl according to claim 1, characterized in that: The pretreatment method in step (1) is: placing the carrier in a muffle furnace and calcining at a temperature of 400° C. for 4 hours.

3. The method for preparing a regenerable solid amine material for adsorbing CNCl according to claim 1, characterized in that: The mixed solution in step (2) was stirred in a magnetic stirrer for 30 min.

4. The method for preparing a regenerable solid amine material for adsorbing CNCl according to claim 1, characterized in that: The organic amine in step (2) is diethylenetriamine, triethylenetetramine or tetraethylenepentamine.

5. The method for preparing a regenerable solid amine material for adsorbing CNCl according to claim 1, characterized in that: During the stirring process in step (3), the container is sealed.

6. The method for preparing a regenerable solid amine material for adsorbing CNCl according to claim 1, characterized in that: The loading amount of the organic amine in the mixture in step (4) is 10wt%-30wt%.

7. The method for preparing a regenerable solid amine material for adsorbing CNCl according to claim 1, characterized in that: The drying condition in the drying oven in step (4) is: drying at 60° C. overnight.

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