Special adsorbing resin for straw extraction and preparation method thereof
By preparing a special adsorption resin for straw extraction, the problems of environmentally unfriendly preparation and low adsorption capacity in existing adsorption resin technologies have been solved, achieving a highly efficient and environmentally friendly adsorption effect for 5-hydroxymethylfurfural.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 安徽皖东树脂科技有限公司
- Filing Date
- 2024-01-03
- Publication Date
- 2026-04-10
AI Technical Summary
In the existing straw hydrolysis process, the preparation of adsorption resin is not environmentally friendly, and the selective adsorption of 5-hydroxyfurfural is poor, resulting in low adsorption capacity.
Polystyrene microspheres were prepared by suspension polymerization, using low-toxicity bromoethane as a crosslinking agent and gallic acid as a modifier. Through post-crosslinking and molecular imprinting techniques, combined with the characteristics of benzene ring and 5-hydroxyfurfural, a special adsorption resin for straw extraction was prepared.
It achieves high adsorption capacity and selectivity for 5-hydroxymethylfurfural, with an adsorption capacity of up to 69.4 mg/g wet resin and an elution rate of over 99.7%, avoiding the use of highly toxic chloromethyl ether, making it environmentally friendly and healthy.
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Figure BDA0004648093940000071 
Figure BDA0004648093940000081
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of adsorption resins, and particularly relates to a special adsorption resin for straw extraction and a preparation method thereof. BACKGROUND
[0002] With the attention to carbon emissions, the treatment and disposal of agricultural waste straw is also a current concern. In the past, incineration was the main way of straw treatment, but with the improvement of environmental pollution and environmental awareness, incineration of straw has been gradually abolished.
[0003] Since corn, wheat and other straws contain a large amount of cellulose polymerized from glucose monomers, which has a structural unit for converting 5-hydroxymethylfurfural, it is an ideal raw material for producing 5-hydroxymethylfurfural. 5-hydroxymethylfurfural is a platform chemical for traditional Chinese medicine, which can be used to prepare 2,5-furan dimethyl ether, 2,5-furan dicarboxylic acid, levulinic acid and other high-value chemicals. Therefore, the use of straw hydrolysis to prepare 5-hydroxymethylfurfural is more and more in practical application. However, in the process of straw hydrolysis, a series of other compounds are formed. In order to obtain 5-hydroxymethylfurfural with high purity, the mixture produced by degradation must be separated and purified. The super-high cross-linked resin has the advantages of high specific surface area, high porosity, high thermal stability, light weight, controllable pore size and the like, and is a new research hotspot in the separation and purification of straw hydrolysis products.
[0004] Although the super-high cross-linked adsorption resin has good adsorption performance, the preparation of the existing super-high cross-linked adsorption resin needs to use chloromethyl ether as a cross-linking agent, which has strong carcinogenicity and is not environmentally friendly. In addition, the selective adsorption of 5-hydroxymethylfurfural is poor, and the adsorption capacity is low. It is necessary to optimize. SUMMARY
[0005] The purpose of the present application is to provide a special adsorption resin for straw extraction and a preparation method thereof, which solves the problems of the existing adsorption resin for extracting 5-hydroxymethylfurfural in the process of straw hydrolysis, which is not environmentally friendly, and has poor selective adsorption of 5-hydroxymethylfurfural and low adsorption capacity.
[0006] The purpose of the present application can be achieved by the following technical solutions:
[0007] A preparation method of a special adsorption resin for straw extraction, comprising the following steps:
[0008] (1) preparing polystyrene microspheres with styrene and divinylbenzene as main raw materials;
[0009] (2) Put the polystyrene microspheres into a reaction kettle containing bromoethane, and add zinc chloride in batches in equal amounts, with an interval of 10 min, and stir for 12 h at 301 K. After cooling to room temperature, perform suction filtration. The suction filtration product is placed in a Soxhlet extractor and extracted with acetone for 8 h. Vacuum drying is performed at 333 K for 2 h to obtain brominated polystyrene microspheres;
[0010] (3) Under nitrogen protection, the brominated polystyrene microspheres are added to a reaction kettle containing nitrobenzene, and after stirring for 12 h, a mixture a composed of 5-hydroxymethylfurfural, gallic acid and dichloroethane is added, and zinc chloride is added. Stirring is performed at 343 K for 4 h, zinc chloride is added again, the temperature is raised to 358-368 K, and stirring is performed for 10 h after cooling to room temperature. Suction filtration is performed, the obtained product is placed in a mixed solution b and ultrasonic treatment is performed for 12-24 h. Suction filtration is performed again, the filter cake is washed with methanol and then placed in a Soxhlet extractor and extracted with acetone for 2 h. Finally, vacuum drying is performed at 333 K for 5 h to obtain a straw extraction special adsorption resin.
[0011] The present application first prepares polystyrene microspheres by using a suspension polymerization method, then uses low-toxicity bromoethane as a crosslinking agent to obtain brominated polystyrene microspheres, and then uses gallic acid as a modifier. On the one hand, the phenolic hydroxyl modifier source is modified to obtain a phenolic hydroxyl modified adsorption resin. On the other hand, the hydrogen bond interaction between the -OH of gallic acid and the -O- and C=O in 5-hydroxymethylfurfural is used to obtain a stable complex. Then, 5-hydroxymethylfurfural is removed through a mixed solution b to obtain an adsorption resin containing shape-matching cavities with 5-hydroxymethylfurfural and having good adsorption performance for 5-hydroxymethylfurfural.
[0012] As a preferred technical solution of the present application, the preparation step of the polystyrene microspheres in step (1) is as follows:
[0013] Deionized water is added to the reaction kettle, and then gelatin is added. Stirring is performed at 333 K until the gelatin is dissolved. Then, a mixture c of styrene, benzoyl peroxide, liquid wax, toluene and divinylbenzene is added. The stirring speed is 100-200 rpm. The temperature is raised to 353 K after stirring for 1 h at 343 K. Stirring is performed for 12 h. After cooling for 4-6 h, suction filtration is performed with a vacuum pump. The resin balls are collected, washed with hot water to remove the gelatin, and then dried. The polystyrene microspheres are obtained by placing them in a Soxhlet extractor and extracting them with acetone for 12 h, and finally vacuum drying them at 333 K for 6 h. The mass ratio of deionized water, gelatin, styrene, benzoyl peroxide, liquid wax, toluene and divinylbenzene is 300:3:44:0.5:15:10:4.5.
[0014] As a preferred technical solution of the present application, the amount ratio of polystyrene microspheres, bromoethane and zinc chloride in step (2) is 28 g:300 mL:11.2 g.
[0015] As a preferred technical scheme of the present application, the ratio of the use amount of brominated polystyrene microspheres, nitrobenzene, 5-hydroxymethylfurfural, gallic acid, dichloroethane and zinc chloride in step (3) is 8-15 g: 60-120 mL: 0.2-0.4 g: 0.8-2.6 g: 10-30 mL: 0.7-2.0 g, and the mass ratio of the first amount of zinc chloride added and the second amount of zinc chloride added is 7-4: 3-5.
[0016] As a preferred technical scheme of the present application, the mixed solution b in step (3) is composed of methanol and acetic acid in a volume ratio of 9:1.
[0017] As a preferred technical scheme of the present application, a special adsorption resin for straw extraction is prepared by the above preparation method.
[0018] The present application has the following beneficial effects:
[0019] 1. The special adsorption resin for straw extraction has a maximum adsorption capacity of 5-hydroxymethylfurfural of 69.4 mg / g wet resin, and an elution rate of more than 99.7%, realizing high adsorption selectivity of 5-hydroxymethylfurfural.
[0020] 2. The special adsorption resin for straw extraction is an ultra-high crosslinking adsorption resin, which uses bromoethane as a crosslinking agent to avoid the use of highly toxic chloromethyl ether, and is more environmentally friendly and healthy.
[0021] 3. The present application uses the widely existing polyphenol compound gallic acid as a modifier and 5-hydroxymethylfurfural as a template molecule to obtain a gallic acid modified ultra-high crosslinking adsorption resin through post-crosslinking and chemical modification and molecular imprinting. The molecular imprinting technology and ultra-high crosslinking adsorption resin are combined to form hydrophobic-hydrophobic interaction and π-π interaction between the benzene ring in the adsorption resin and the furan ring in 5-hydroxymethylfurfural, and hydrogen bonding and electrostatic force interaction between the carboxyl and phenolic hydroxyl groups and the hydroxymethyl group in 5-hydroxymethylfurfural, thereby efficiently adsorbing 5-hydroxymethylfurfural. In addition, the adsorption resin also has imprinting cavities left by 5-hydroxymethylfurfural molecules, which can completely match the morphology of 5-hydroxymethylfurfural, realize selective adsorption of 5-hydroxymethylfurfural, and increase the adsorption capacity of the adsorption resin for 5-hydroxymethylfurfural. DETAILED DESCRIPTION
[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.
[0023] Example 1
[0024] A preparation method of a special adsorption resin for straw extraction, comprising the following steps:
[0025] (1) preparing polystyrene microspheres by taking styrene and divinylbenzene as main raw materials;
[0026] (2) putting 28 g of polystyrene microspheres into a reaction kettle containing 300 mL of bromoethane, adding 11.2 g of zinc chloride in three equal portions with an interval of 10 min, stirring and reacting at 301 K for 12 h, cooling to room temperature, and then performing suction filtration; the suction filtration product is placed in a Soxhlet extractor and extracted with acetone for 8 h, and then vacuum dried at 333 K for 2 h to obtain brominated polystyrene microspheres;
[0027] (3) under the protection of nitrogen, 8 g of brominated polystyrene microspheres are added into a reaction kettle containing 60 mL of nitrobenzene, and after stirring for 12 h, a mixture a composed of 0.2 g of 5-hydroxymethylfurfural, 0.8 g of gallic acid and 10 mL of dichloroethane is added, 0.4 g of zinc chloride is added, stirring and reacting at 343 K for 4 h, 0.3 g of zinc chloride is added again, the temperature is raised to 358 K, and stirring and reacting for 10 h, and then cooling to room temperature, suction filtration, and ultrasonic treatment of the obtained product in a mixed solution b for 12 h, wherein the mixed solution b is composed of methanol and acetic acid in a volume ratio of 9:1, and then suction filtration, washing the filter cake with methanol, placing the filter cake in a Soxhlet extractor, extracting with acetone for 2 h, and finally vacuum drying at 333 K for 5 h to obtain the special adsorption resin for straw extraction.
[0028] In the step (1), the preparation steps of the polystyrene microspheres are as follows:
[0029] 300 mL of deionized water is added into a reaction kettle, and then 3 g of gelatin is added, stirring until the gelatin is dissolved at 333 K, and then a mixture c composed of 44 g of styrene, 0.5 g of benzoyl peroxide, 15 g of liquid wax, 10 g of toluene and 4.5 g of divinylbenzene is added, stirring at a rotation speed of 100 rpm for 1 h at 343 K, and then the temperature is raised to 353 K, and stirring and reacting for 12 h, and then cooling for 4 h, and then performing suction filtration with a vacuum pump, collecting the resin balls, washing with hot water to remove the gelatin, and then drying, placing in a Soxhlet extractor, and extracting with acetone for 12 h, and finally vacuum drying at 333 K for 6 h to obtain the polystyrene microspheres.
[0030] Example 2
[0031] A preparation method of a special adsorption resin for straw extraction, comprising the following steps:
[0032] (1) preparing polystyrene microspheres by taking styrene and divinylbenzene as main raw materials;
[0033] (2) Put 28 g of polystyrene microspheres into a reaction kettle containing 300 mL of bromoethane, add 11.2 g of zinc chloride in three equal portions with an interval of 10 min, stir at 301 K for 12 h, cool to room temperature, and then filter under vacuum. The filtered product is placed in a Soxhlet extractor and extracted with acetone for 8 h. After vacuum drying at 333 K for 2 h, brominated polystyrene microspheres are obtained;
[0034] (3) Under nitrogen protection, 11 g of brominated polystyrene microspheres are added to a reaction kettle containing 90 mL of nitrobenzene, and stirred for 12 h. Then, a mixture a composed of 0.3 g of 5-hydroxymethylfurfural, 1.2 g of gallic acid, and 20 mL of dichloroethane is added, followed by the addition of 1.05 g of zinc chloride. The reaction is stirred at 343 K for 4 h, and then 0.45 g of zinc chloride is added again. The temperature is raised to 362 K, and the reaction is stirred for 10 h before being cooled to room temperature. The product is filtered under vacuum, and then ultrasonically treated in a mixed solution b composed of methanol and acetic acid in a volume ratio of 9:1 for 16 h. After being filtered again, the filter cake is washed with methanol and then placed in a Soxhlet extractor for extraction with acetone for 2 h. Finally, the product is vacuum dried at 333 K for 5 h to obtain a straw extraction special adsorption resin.
[0035] In step (1), the preparation of polystyrene microspheres is as follows:
[0036] A mixture c composed of 44 g of styrene, 0.5 g of benzoyl peroxide, 15 g of liquid wax, 10 g of toluene, and 4.5 g of divinylbenzene is added to the reaction kettle containing 300 mL of deionized water and 3 g of gelatin. The mixture is stirred at 333 K until the gelatin is dissolved. Then, the temperature is raised to 343 K, and the reaction is stirred at 150 rpm for 1 h. The temperature is then raised to 353 K, and the reaction is stirred for 12 h. After being cooled for 5 h, the product is filtered under vacuum. After being washed with hot water to remove the gelatin, the product is dried, placed in a Soxhlet extractor, and extracted with acetone for 12 h. Finally, the product is vacuum dried at 333 K for 6 h to obtain polystyrene microspheres.
[0037] Example 3
[0038] A method for preparing a straw extraction special adsorption resin includes the following steps:
[0039] (1) Polystyrene microspheres are prepared using styrene and divinylbenzene as main raw materials;
[0040] (2) 28 g of polystyrene microspheres are placed in a reaction kettle containing 300 mL of bromoethane. 11.2 g of zinc chloride is added in three equal portions with an interval of 10 min. The reaction is stirred at 301 K for 12 h. After being cooled to room temperature, the product is filtered under vacuum. The filtered product is placed in a Soxhlet extractor and extracted with acetone for 8 h. After vacuum drying at 333 K for 2 h, brominated polystyrene microspheres are obtained;
[0041] (3) Under the protection of nitrogen, 15 g of brominated polystyrene microspheres were added to a reaction kettle containing 120 mL of nitrobenzene, and stirred for 12 h. Then, a mixture a composed of 0.4 g of 5-hydroxymethylfurfural, 2.6 g of gallic acid, and 30 mL of dichloroethane was added, followed by the addition of 1.0 g of zinc chloride. The reaction was stirred at 343 K for 4 h, and then 1.0 g of zinc chloride was added again. The temperature was raised to 368 K, and the reaction was stirred for 10 h before being cooled to room temperature. Filtration was performed, and the obtained product was placed in a mixed solution b composed of methanol and acetic acid in a volume ratio of 9:1 for ultrasonic treatment for 24 h. Filtration was performed again, and the filter cake was washed with methanol and then placed in a Soxhlet extractor for extraction with acetone for 2 h. Finally, vacuum drying was performed at 333 K for 5 h to obtain the straw extraction special adsorption resin.
[0042] In step (1), the preparation of polystyrene microspheres is as follows:
[0043] A mixture c composed of 44 g of styrene, 0.5 g of benzoyl peroxide, 15 g of liquid wax, 10 g of toluene, and 4.5 g of divinylbenzene was added to the reaction kettle containing 300 mL of deionized water and 3 g of gelatin. The mixture was stirred at 333 K until the gelatin was dissolved. The stirring speed was 200 rpm, and the reaction was performed at 343 K for 1 h before being raised to 353 K for 12 h. After cooling for 6 h, the product was collected by filtration using a vacuum pump. The resin balls were washed with hot water to remove the gelatin and then dried. The product was placed in a Soxhlet extractor for extraction with acetone for 12 h. Finally, vacuum drying was performed at 333 K for 6 h to obtain the polystyrene microspheres.
[0044] Comparative Example 1
[0045] A method for preparing a straw extraction special adsorption resin, in which the gallic acid in Example 1 is replaced with an equal amount of phenol, and the remaining raw materials and preparation process are the same as in Example 1.
[0046] Comparative Example 2
[0047] A method for preparing a straw extraction special adsorption resin, in which the 5-hydroxymethylfurfural in Example 1 is removed, and the remaining raw materials and preparation process are the same as in Example 1.
[0048] The straw extraction special adsorption resins obtained in Examples 1-3 and Comparative Examples 1-2 were detected, and the detection process was as follows:
[0049] (I) The specific surface area and pore size distribution of the resin were determined using a specific surface area and pore size analyzer, and the test results are shown in Table 1:
[0050] Table 1
[0051]
[0052] As can be seen from the data recorded in Table 1, the specific surface area of the adsorption resins obtained in Example 1, Example 2 and Example 3 is lower than that of Comparative Example 1 and Comparative Example 2, but the pore size is increased, which indicates that the polarity of the carboxyl and phenolic hydroxyl groups introduced by gallic acid compared with phenol can cause the internal pore structure of the resin to collapse, resulting in a decrease in the specific surface area, and after molecular imprinting, the surface of the resin produces imprinted cavities matched with 5-hydroxymethylfurfural molecules, which are larger than the surface pore holes of the resin without imprinting, and the interaction between the polar groups and 5-hydroxymethylfurfural is conducive to the adsorption of 5-hydroxymethylfurfural.
[0053] (II) Adsorption performance test
[0054] The adsorption resins prepared in Examples 1-3 and Comparative Examples 1-2 were placed in a 95% ethanol solution for swelling for 24 h, then washed with deionized water until no odor was detected, and then wet resins were obtained by suction filtration. 0.25 g of each group of wet resins was weighed and added to 25 mL of corn stalk hydrolysate system, and the sample was placed in a shaking incubator at 25°C and shaken at 120 rpm for 240 min. After reaching adsorption equilibrium, the adsorption resin was separated from the solution; wherein the concentration of 5-hydroxymethylfurfural in the corn stalk hydrolysate system was 5.0 g / L, the concentration of levulinic acid was 2.5 g / L, the concentration of formic acid was 1.0 g / L, and the concentration of glucose was 1.0 g / L. The detection method of the adsorption capacity was high performance liquid chromatography detection method, and the specific test conditions were as follows: the mobile phase used for testing was 5 mM dilute sulfuric acid solution, the flow rate was 0.5 mL / min; the chromatographic column was HPX-87H; the test temperature was 55°C; the injection volume was 10 μL;
[0055] The test results are shown in Table 2:
[0056] Table 2
[0057]
[0058] As can be seen from the data recorded in Table 2, compared with Comparative Example 1 and Comparative Example 2, the adsorption capacity of the adsorption resins obtained in Example 1, Example 2 and Example 3 for 5-hydroxymethylfurfural can reach 69.4 mg / g of wet resin, and the elution rate is ≥99.7%, which realizes high-efficiency adsorption and separation of 5-hydroxymethylfurfural.
[0059] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be apparent that the scope of the present application is not limited to these specific embodiments.
[0060] While the embodiments of the application have been shown and described herein, it will be understood by those skilled in the art that many changes, modifications, substitutions and alterations to these embodiments can be made without departing from the principles and spirits of the application, and it is intended that the scope of the application be limited solely by the scope of the appended claims and the equivalents thereof.
Claims
1. A method for preparing an adsorption resin for extracting 5-hydroxymethylfurfural from straw hydrolysis, characterized in that, Includes the following steps: (1) Polystyrene microspheres were prepared using styrene and divinylbenzene as the main raw materials; (2) Place polystyrene microspheres in bromoethane, add zinc chloride in batches in equal amounts, stir and react at 301K for 12h, cool and filter, extract the filtered product with a Soxhlet extractor, and dry under vacuum to obtain brominated polystyrene microspheres. (3) Under nitrogen protection, brominated polystyrene microspheres were added to nitrobenzene and stirred for 12 h. Then, a mixture a consisting of 5-hydroxymethylfurfural, gallic acid and dichloroethane was added, and zinc chloride was added. The mixture was stirred at 343 K for 4 h. Zinc chloride was added again, and the temperature was raised to 358-368 K. After stirring for 10 h, the mixture was cooled and filtered. The product was placed in mixed solution b and ultrasonically treated for 12-24 h. After filtration, the filter cake was washed and placed in a Soxhlet extractor for extraction. After vacuum drying, the adsorption resin for extracting 5-hydroxymethylfurfural from straw hydrolysis was obtained. The adsorption resin used to extract 5-hydroxymethylfurfural from straw hydrolysis showed an adsorption capacity of up to 69.4 mg / g wet resin and an elution rate of over 99.7%, achieving high adsorption selectivity for 5-hydroxymethylfurfural.
2. The method for preparing an adsorption resin for extracting 5-hydroxymethylfurfural from straw hydrolysis according to claim 1, characterized in that, The preparation steps of polystyrene microspheres in step (1) are as follows: Deionized water and gelatin were mixed and stirred at 333K until the gelatin dissolved. Then, a mixture of styrene, benzoyl peroxide, liquid wax, toluene, and divinylbenzene (c) was added. The mixture was stirred at 343K for 1 hour, then heated to 353K and stirred for 12 hours. After cooling for 4-6 hours, the mixture was filtered using a vacuum pump, and the resin balls were collected. After washing with hot water and drying, the mixture was extracted with acetone in a Soxhlet extractor for 12 hours. Finally, the mixture was vacuum dried at 333K for 6 hours to obtain polystyrene microspheres. The mass ratio of deionized water, gelatin, styrene, benzoyl peroxide, liquid wax, toluene, and divinylbenzene was 300:3:44:0.5:15:10:4.
5.
3. The method for preparing an adsorption resin for extracting 5-hydroxymethylfurfural from straw hydrolysis according to claim 1, characterized in that, In step (2), the ratio of polystyrene microspheres, bromoethane and zinc chloride is 28g:300mL:11.2g.
4. The method for preparing an adsorption resin for extracting 5-hydroxymethylfurfural from straw hydrolysis according to claim 1, characterized in that, In step (3), the ratio of brominated polystyrene microspheres, nitrobenzene, 5-hydroxymethylfurfural, gallic acid, dichloroethane and zinc chloride is 8-15g: 60-120mL: 0.2-0.4g: 0.8-2.6g: 10-30mL: 0.7-2.0g, and the mass ratio of the first addition of zinc chloride to the second addition of zinc chloride is 7-4: 3-5.
5. The method for preparing an adsorption resin for extracting 5-hydroxymethylfurfural from straw hydrolysis according to claim 1, characterized in that, In step (3), the mixed solution b is composed of methanol and acetic acid in a volume ratio of 9:
1.
6. An adsorption resin for extracting 5-hydroxymethylfurfural from straw hydrolysis, characterized in that, It is prepared by the preparation method described in any one of claims 1-5.