CN111514866A - Solvent recovery efficient wood activated carbon and preparation method thereof - Google Patents

Abstract

The invention discloses a solvent recovery high-efficiency wood activated carbon and a preparation method thereof. The raw material weight ratio is: 95-105 parts of wood powder carbon, 15-22 parts of polyvinyl alcohol, 0.5-5 parts of surfactant, and 0.5 parts of cross-linking agent. ‑5 parts and 95‑105 parts of water, using wood powder charcoal as raw charcoal, polyvinyl alcohol, surfactant, cross-linking agent and water are mixed to form an adhesive, and the adhesive and wood powder charcoal are mixed and bonded to form , the activated carbon has less pore structure blocked, and the prepared activated carbon has a more developed pore structure and better bonding strength, which improves the acid and alkali resistance, and does not lose ash when used. Acid and alkali resistance problem, the total amount of adsorption is increased by 5-10 times, and the service life of activated carbon is further improved. It can be well applied to solvent recovery, reducing enterprise costs and improving efficiency.

Description

A kind of solvent recovery high-efficiency wood activated carbon and preparation method thereof

【Technical field】

The invention relates to the technical field of activated carbon, in particular to a solvent recovery high-efficiency wood activated carbon and a preparation method thereof.

【Background technique】

With the deepening of industrialization, the water, soil and air that human beings depend on are becoming more and more polluted, and more and more waste water, waste residue and waste gas are discharged by enterprises. The three wastes seriously affect people's quality of life, and environmental governance has become very Important, the country is also vigorously promoting. The three wastes produced by the enterprise must be treated and meet the emission standards before they can be discharged. The most ideal, most effective and most environmentally friendly way to remove these harmful substances is to use activated carbon.

Activated carbon is a substance with developed pores and stable chemical properties. At present, most enterprises use coal-based activated carbon for treatment, but there are disadvantages such as relatively high cost, unsatisfactory treatment effect, and short service life, which not only increases the cost of the enterprise, but also disposes of used activated carbon (hazardous waste). .

The development of wood activated carbon for solvent recovery is very late, and its share in this field is not high. The fundamental reasons are: 1. The acid and alkali resistance is average. When encountering acid or alkali, the adhesive will quickly lose its viscosity, resulting in The wood activated carbon is broken or chipped, causing losses; 2. The adhesive blocks the carbon pores, and the adhesive in the existing wood activated carbon easily penetrates into the activated carbon pores, which has a certain impact on the pores of the formed activated carbon, resulting in a relatively long service life of the wood activated carbon. short. Therefore, it is necessary to solve the problems of clogging carbon pores and acid and alkali resistance by adhesives, otherwise it is difficult for wood activated carbon to be suitable for solvent recovery.

[Content of the invention]

The purpose of the present invention is to solve the problem that the service life of the existing activated carbon is relatively short, and to provide a high-efficiency modified activated carbon that can adsorb various VOC gases and increase the adsorption capacity, which can improve the service life of the activated carbon and reduce the production cost of the enterprise.

Another object of the present invention is to provide a method for preparing high-efficiency wood-based activated carbon for solvent recovery.

The present invention provides the following technical solutions: a solvent recovery high-efficiency wood activated carbon, the raw material weight ratio is: 95-105 parts of wood powder carbon, 15-22 parts of polyvinyl alcohol, 0.5-5 parts of surfactant, and 0.5-5 parts of cross-linking agent parts and 95-105 parts of water.

A kind of solvent recovery high-efficiency wood activated carbon of the present application, using wood powder carbon as raw carbon, polyvinyl alcohol, surfactant, cross-linking agent and water are mixed and prepared into an adhesive, which is compounded, mixed and extruded according to a certain proportion. It is prepared by molding, crushing and sieving. During the preparation process of the adhesive, polyvinyl alcohol as a binder and a cross-linking agent are mixed with a cross-linking reaction, and the original linear structure is cross-connected and becomes a spatial network structure. , it is difficult to form a polymer cross-linked product with a large molecular weight into the pores of the activated carbon. At the same time, the polymer cross-linked product with a spatial network structure not only increases the viscosity but also improves the acid and alkali resistance, making the bonding performance better. The addition of surfactant improves the dispersion degree of the polymer cross-linked product, and at the same time plays a thickening effect, solves the problem of agglomeration, and further improves the flexibility and viscosity of the adhesive under the catalytic modification of the surfactant. The wood activated carbon obtained by mixing the adhesive and wood powder carbon has a larger specific surface area, and the pore structure of the activated carbon is less blocked, and the prepared activated carbon has a more developed pore structure and better adhesion. Bond strength, the more developed the microporous structure, the stronger the adsorption performance of the formed wood activated carbon, the increase of the bonding strength makes the formed product no longer react with acid or alkali, and then improves the acid and alkali resistance, and does not lose ash during use, this application It solves the problem of cross-linking agent blocking carbon pores and acid and alkali resistance, and can be well applied to solvent recovery, which can greatly reduce enterprise costs and improve efficiency.

Preferably, the wood powdered carbon is wood powder activated carbon with mesh number ≥ 200 mesh, iodine value ≥ 1100 mg/g, and pH value ≥ 5.6 produced by phosphoric acid method. The wood powdered carbon is a special powdered activated carbon for sewage, has developed mesoporous structure, large adsorption capacity, fast filtration and other characteristics, which can improve the recovery rate of the solvent.

Preferably, the polyvinyl alcohol is one or a combination of PVA1792, PVA1799, PVA2099, PVA2092, PVA2499 and PVA2492. Its function is as an adhesive, which can cross-link with other components in the adhesive to form a network cross-linked product, cross-link the PVA linear structure to form a network structure, improve acid and alkali resistance, and make activated carbon pores. Evenly distributed and sized.

Preferably, the surfactant is one or a combination of coconut oil and sodium lauryl sulfonate. The function of the surfactant is to improve the adsorption capacity of the activated carbon. Sodium dodecyl sulfonate acts as an anionic surfactant to thicken, change the rheological properties of polyvinyl alcohol, and improve the dispersibility and compatibility of polyvinyl alcohol.

Preferably, the crosslinking agent is one or a combination of borax and starch. Its function is to combine and solidify the carbon molecules after cross-linking with polyvinyl alcohol, so that the solidified pore structure is suitable for the adsorption of harmful substances. Borax can be cross-linked with the cis-hydroxyl group of polyvinyl alcohol, so that the original linear structure becomes a network structure, and the formed polymer cross-linked product with a spatial network structure has shear resistance and acid and alkali resistance. and other properties, so the viscosity increases and the bonding performance becomes better.

A preparation method of solvent recovery high-efficiency wood activated carbon, comprising the following steps:

S1. Material preparation: prepare the raw materials according to the weight ratio, spare;

S2. Preparation of adhesive: Add polyvinyl alcohol into water and stir evenly, let stand for 4-6 hours, then stir at high speed for 10-20 minutes, add surfactant and stir at medium speed for 4-6 minutes, and then add in cross-linking agent Stir at high speed for 4-6 minutes;

S3. Mixing: Add the wood powder charcoal and the adhesive to the reaction kettle, stir while adding, and continue stirring for 0.5-2 hours after the addition is complete;

S4, granulation and molding: after mixing, it is sent to the granulation equipment and extruded into granular carbon;

S5. Baking: Bake the granular charcoal to a moisture content of ≤5%;

S6, crushing and sieving: the baked granular carbon is sent to crushing equipment to be crushed, and then sieved after crushing.

Preferably, in step S4, it is extruded into granular carbon with a particle size of 2-5 mm.

Preferably, in step S5, baking is performed at a temperature of 80-150° C. for 2-8 hours.

Preferably, step S6 specifically includes: sending the baked granular carbon into a crushing device to be crushed into granular shapes with a size of 0.9mm-9mm, sieving after crushing, and selecting a granular vacuum that meets the requirements of particle size and length. Package.

Preferably, the medium-speed stirring is stirring at a rotational speed of 300-500 r/min, and the high-speed stirring is stirring at a rotational speed of 800-1000 r/min.

Compared with the prior art, the present invention has the following advantages:

The present invention is a solvent recovery high-efficiency wood activated carbon, and the raw material weight ratio is: 95-105 parts of wood powder carbon, 15-22 parts of polyvinyl alcohol, 0.5-5 parts of surfactant, 0.5-5 parts of cross-linking agent and 95 parts of water -105 parts, using wood powder charcoal as raw charcoal, polyvinyl alcohol, surfactant, cross-linking agent and water are mixed to prepare an adhesive, which is prepared by compounding, mixing, extrusion molding, crushing and sieving according to a certain proportion During the preparation of the adhesive, the cross-linking reaction occurs when the polyvinyl alcohol is used as the adhesive and the cross-linking agent is mixed, and the original linear structure is cross-connected into a spatial network structure, forming a high molecular weight high molecular weight. It is difficult for the polymer cross-links to enter the pores of the activated carbon, and the high-polymer cross-links with a spatial network structure not only increase the viscosity but also improve the acid and alkali resistance, making the bonding performance better, and the addition of surfactants improves The dispersion degree of the polymer cross-linked product is improved, and at the same time, it has a thickening effect and solves the problem of agglomeration. Under the catalytic modification of the surfactant, the flexibility and bonding performance of the adhesive are further improved. After mixing and bonding with wood powder carbon, the activated carbon has less pore structure blocked. The prepared activated carbon has a more developed pore structure and better bonding strength. The more developed the microporous structure, the stronger the adsorption performance of the formed wood activated carbon. The increase in bonding strength makes the molded product no longer react with acid or alkali, thereby improving the acid and alkali resistance, and no ash will be lost when used. -10 times, further improve the service life of activated carbon, can be well applied to solvent recovery, reduce enterprise cost and improve efficiency.

The preparation method of the solvent recovery high-efficiency wood activated carbon of the invention has the advantages of simple preparation technology, and the wood powder carbon raw material is produced by a special process, the service life of the solvent recovery high-efficiency wood activated carbon can be increased by more than 50%, and the enterprise use cost can be reduced by more than 30%. , suitable for mass continuous production.

【Detailed ways】

The specific technical solutions of the present invention are described below in conjunction with specific embodiments 1 to 4:

Example 1:

A kind of preparation method of solvent recovery high-efficiency wood activated carbon, comprises the following steps:

S1. Material preparation: prepare the raw materials according to the weight ratio in Table 1, for use;

S2. Preparation of adhesive: add polyvinyl alcohol into water and stir evenly, let stand for 6 hours, then stir at high speed for 10 minutes, add surfactant and stir at medium speed for 4 minutes, and then add crosslinking agent and stir at medium speed for 4 minutes. ;

S3. Mixing: add the wood powder charcoal and the adhesive to the reaction kettle at a weight ratio of 100:22, and stir while adding, and continue stirring for 1 hour after the addition is complete;

S4, granulation and molding: after mixing, it is sent to the granulation equipment, and extruded into granular carbon with a particle size of 2-5mm;

S5. Baking: Bake the granular carbon at a temperature of 120 °C for 4 hours, and the detected moisture content is less than or equal to 5%;

S6. Crushing and sieving: The baked granular carbon is sent to the crushing equipment to be crushed into granules with a size of 0.9mm-9mm, and then sieved after crushing, and the granular vacuum packaging that meets the requirements of particle size and length is selected. That is (the above-mentioned high-speed stirring is 1000 r/min, and the medium-speed stirring is 500 r/min).

Example 2:

A kind of preparation method of solvent recovery high-efficiency wood activated carbon, comprises the following steps:

S1. Material preparation: prepare the raw materials according to the weight ratio in Table 1, for use;

S2. Preparation of adhesive: Add polyvinyl alcohol into water and stir evenly, let stand for 5 hours, then stir at high speed for 20 minutes, add surfactant and stir at medium speed for 5 minutes, and then add crosslinking agent and stir at medium speed for 5 minutes. ;

S3. Mixing: add the wood powder charcoal and the adhesive to the reaction kettle at a weight ratio of 100:30, stir while adding, and continue stirring for 1.5 hours after the addition is complete;

S4, granulation and molding: after mixing, it is sent to the granulation equipment, and extruded into granular carbon with a particle size of 2-5mm;

S5. Baking: Bake the granular carbon at a temperature of 150 °C for 2 hours, and the moisture content is less than or equal to 5%;

S6. Crushing and sieving: The baked granular carbon is sent to the crushing equipment to be crushed into granules with a size of 0.9mm-9mm, and then sieved after crushing, and the granular vacuum packaging that meets the requirements of particle size and length is selected. That is (the above-mentioned high-speed stirring is 800 r/min, and the medium-speed stirring is 300 r/min).

Example 3:

S1. Material preparation: prepare the raw materials according to the weight ratio in Table 1, for use;

S2. Preparation of adhesive: Add polyvinyl alcohol into water and stir evenly, let stand for 4 hours, then stir at high speed for 15 minutes, add surfactant and stir at medium speed for 5 minutes, and then add crosslinking agent and stir at medium speed for 5 minutes. ;

S3. Mixing: Add the wood powder charcoal and the adhesive to the reaction kettle in a weight ratio of 100:1, and stir while adding, and continue stirring for 0.5 hours after the addition is complete;

S4, granulation and molding: after mixing, it is sent to the granulation equipment, and extruded into granular carbon with a particle size of 2-5mm;

S5. Baking: Bake the granular carbon at a temperature of 80 °C for 8 hours, and the detected moisture content is less than or equal to 5%;

S6. Crushing and sieving: The baked granular carbon is sent to the crushing equipment to be crushed into granules with a size of 0.9mm-9mm, and then sieved after crushing, and the granular vacuum packaging that meets the requirements of particle size and length is selected. That is (the above high-speed stirring is 900 r/min, and the medium-speed stirring is 400 r/min).

Example 4:

S1. Material preparation: prepare the raw materials according to the weight ratio in Table 1, for use;

S2. Preparation of adhesive: add polyvinyl alcohol into water and stir evenly, let stand for 4.5 hours, then stir at high speed for 12 minutes, add surfactant and stir at medium speed for 5.5 minutes, and then add crosslinking agent and stir at medium speed for 5.5 minutes. ;

S3. Mixing: add the wood powder charcoal and the adhesive to the reaction kettle in a weight ratio of 100:14, stir while adding, and continue stirring for 1 hour after the addition is complete;

S4, granulation and molding: after mixing, it is sent to the granulation equipment, and extruded into granular carbon with a particle size of 2-5mm;

S5. Baking: Bake the granular carbon at a temperature of 130 °C for 3 hours, and the detected moisture content is less than or equal to 5%;

S6. Crushing and sieving: The baked granular carbon is sent to the crushing equipment to be crushed into granules with a size of 0.9mm-9mm, and then sieved after crushing, and the granular vacuum packaging that meets the requirements of particle size and length is selected. That is (the above-mentioned high-speed stirring is 1000 r/min, and the medium-speed stirring is 500 r/min).

Table 1: The component allocation ratio of embodiment 1～4 solvent recovery high-efficiency wood activated carbon:

Test experiment:

1. Total amount of adsorption: Take the same amount of solvent recovery high-efficiency wood activated carbon prepared in Examples 1 to 4 and commercially available wood activated carbon of a certain brand (comparative example) to treat sewage under the same conditions, and carry out the total adsorption test of activated carbon, The test results are shown in Table 2. The formula for calculating the total amount q adsorbed by activated carbon is: q=V(C ₀ -C _i )/W; where V is the volume of sewage, in L; C ₀ is the initial concentration of organic matter in the raw sewage before adsorption, in mg/L; C _i is Equilibrium concentration of organic matter in water after adsorption, unit mg/L; W is the amount of wood activated carbon, unit g.

2. Acid resistance: The solvent recovery high-efficiency wood activated carbon prepared in Examples 1 to 4 and the commercially available wood activated carbon of a certain brand (comparative example) were soaked in hydrochloric acid solution, and the changes of the experimental samples were observed. The test results are shown in Table 2.

3. Alkali resistance: the solvent recovery high-efficiency wood activated carbon prepared in Examples 1 to 4 and the commercially available wood activated carbon of a certain brand (comparative example) were soaked in sodium carbonate solution, and the changes of the experimental samples were observed, and the test results were shown in Table 2. Show.

4. Purification ability test, test the CADR value of the solvent recovery high-efficiency wood activated carbon prepared in Examples 1 to 4 and the commercially available wood activated carbon of a certain brand (comparative example), test instrument: laser particle counter, test environment: temperature is: 25±1.5℃, humidity: 40±5%, the test results are shown in Table 2.

Table 2 Test results:

From the test data in Table 2, it can be seen that the total amount of adsorption in the examples of the present application can be increased by 5-10 times compared with the comparative examples. After the adhesive of the present application is cured, the size and distribution of the activated carbon pores can be made uniform, so as to avoid blocking the activated carbon pores and improve the pore size. The density and pore structure are suitable for the adsorption of harmful substances, while the comparative example loses a lot of effective adsorption pores due to the blockage of the gaps between the carbon molecules, resulting in poisoning and no longer adsorption after a certain amount of adsorption. In addition, the present application has good acid and alkali resistance, and the adhesive undergoes a cross-linking reaction during the production process, so that the product no longer reacts with acid or alkali, thereby improving acid and alkali resistance, and does not lose ash during use, and The proportion of acid or alkali will destroy the glue inside, so that the glue quickly loses its viscosity, and then the carbon loses its connection and falls off, so that the carbon particles are dispersed and become mud-like and lose their effect; compared with the comparative example, the present application also has a good purification effect. Ability; the application solves the problem of crosslinking agent blocking carbon pores and acid and alkali resistance, can be well applied to solvent recovery, can greatly reduce enterprise costs and improve efficiency.

Claims (10)

1. a solvent recovery high-efficiency wood activated carbon is characterized in that, its raw material weight proportioning is: 95-105 parts of wood powder carbon, 15-22 parts of polyvinyl alcohol, 0.5-5 part of surfactant, 0.5-5 part of crosslinking agent parts and 95-105 parts of water. 2. a kind of solvent recovery high-efficiency wood activated carbon according to claim 1, is characterized in that: described wood powder charcoal is the wood that adopts phosphoric acid method to produce order number ≥ 200 orders, iodine value ≥ 1100mg/g, pH value ≥ 5.6 Powdered activated carbon. 3. a kind of solvent recovery high-efficiency wood activated carbon according to claim 1 is characterized in that: described polyvinyl alcohol is one or more combinations in PVA1792, PVA1799, PVA2099, PVA2092, PVA2499, PVA2492. 4. a kind of solvent recovery high-efficiency wood activated carbon according to claim 1 is characterized in that: described tensio-active agent is one or a combination in coconut oil, sodium dodecyl sulfonate. 5. a kind of solvent recovery high-efficiency wood activated carbon according to claim 1 is characterized in that: described cross-linking agent is one or a combination of borax and starch. 6. a preparation method of solvent recovery high-efficiency wood activated carbon according to any one of claims 1-5, is characterized in that comprising the following steps: S1. Material preparation: prepare the raw materials according to the weight ratio, spare; S2. Preparation of adhesive: add polyvinyl alcohol into water and stir evenly, let stand for 4-6 hours, then stir at high speed for 10-20 minutes, then add surfactant and stir at medium speed for 4-6 minutes, and then add cross-linking agent Mix at medium speed for 4-6 minutes; S3. Mixing: Add the wood powder charcoal and the adhesive to the reaction kettle, stir while adding, and continue stirring for 0.5-2 hours after the addition is complete; S4, granulation and molding: after mixing, it is sent to the granulation equipment and extruded into granular carbon; S5. Baking: Bake the granular charcoal to a moisture content of ≤5%; S6, crushing and sieving: the baked granular carbon is sent to crushing equipment to be crushed, and then sieved after crushing. 7. The preparation method of solvent recovery high-efficiency wood activated carbon according to claim 6, characterized in that: in step S5, baking is performed at a temperature of 80-150° C. for 2-8 hours. 8. The preparation method of solvent recovery high-efficiency wood-based activated carbon according to claim 6, characterized in that: step S6 specifically comprises: sending the baked granular carbon into a crushing device to be crushed into granular particles with a specification of 0.9mm-9mm , sieve after crushing, and select granular vacuum packaging that meets the requirements of particle size and length. 9. the preparation method of solvent recovery high-efficiency wood-based activated carbon according to claim 6, is characterized in that: described medium-speed stirring is stirring with the rotating speed of 300-500r/min, and described high-speed stirring is with 800-1000r/min Stir at speed. 10. The method for preparing high-efficiency wood-based activated carbon for solvent recovery according to claim 6, characterized in that: in step S4, it is extruded into granular carbon with a particle size of 2-5 mm.