Regeneration method of working solution for producing hydrogen peroxide by anthraquinone process

Abstract

The invention provides a regeneration method of a working solution for production of hydrogen peroxide by an anthraquinone process, and belongs to the technical field of hydrogen peroxide synthesizing.The regeneration method comprises the steps that the working solution is introduced into a regeneration bed and makes contact with an internal regenerant to be regenerated for a period of time, then the working solution is output, and the regenerated working solution is obtained. A surface modification method comprises the following steps: adding a CaOMnO2 / modified aluminum oxide compound into deionized water, stirring for 5-7 hours, adding tetraethyl orthosilicate, carrying out ultrasonic dispersion, reacting for 20-30 hours, centrifuging, cleaning the precipitate, adding into an ethylenediaminetetraacetic acid solution, adding 3-aminopropyltriethoxysilane, stirring for reacting for 3-4 hours, filtering, washing, and drying to obtain the CaOMnO2 / modified aluminum oxide composite material. The regeneration agent provided by the invention has the advantages that the regeneration effect is good, the regeneration increment is 16.12-21.45 g / L, and the service life is 99-108 days.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen peroxide synthesis, and in particular relates to a method for regenerating a working fluid for producing hydrogen peroxide by an anthraquinone process. Background Art

[0002] Hydrogen peroxide, that is, an aqueous solution of hydrogen peroxide, is a colorless, transparent liquid with a slightly irritating odor. It has strong oxidizing and bleaching properties, weak reducing properties, and weak acidity. Due to its unique chemical properties, hydrogen peroxide is widely used in medical disinfection, dyeing and bleaching, oxygen preparation, food processing, water treatment and other fields.

[0003] At present, the synthesis methods of hydrogen peroxide mainly include water electrolysis method, alcohol oxidation method, catalase method, anthraquinone method, etc. Among them, the anthraquinone method is the most important method for industrial production of hydrogen peroxide, accounting for about 95% of the global production. The principle of this method is to dissolve anthraquinone in an appropriate solvent to form a working solution, and then cyclically hydrogenate and oxidize anthraquinone under the joint action of a catalyst, hydrogen and oxygen to generate hydrogen peroxide at the same time, and then obtain a hydrogen peroxide product through extraction and post-treatment steps. However, in the process of cyclic hydrogenation and oxidation of anthraquinone, anthraquinone will undergo side reactions to generate a series of degradation products. The accumulation of degradation products will affect the quality of hydrogen peroxide products and the stable operation of production equipment. The use of suitable catalysts can regenerate degradation products and reconvert them into effective anthraquinone, reduce the content of degradation products in the working solution, and reduce the impact of degradation product accumulation on production.

[0004] Currently, activated alumina is used in industry to regenerate degradation products. However, 1. The mechanical strength of activated alumina is insufficient and its stability is poor, which makes it easy to pulverize in the alkaline working solution, increasing the burden of alkali separation in the post-treatment process; 2. Some degradation products and solvent components in the working solution are crystallized and precipitated on the surface of the activated alumina, which will block the pores, resulting in a decrease in the effective surface area of ​​the activated alumina and a decrease in catalytic activity.

[0005] Patent CN105174229A discloses a composite anthraquinone method hydrogen peroxide working fluid active regeneration agent and a preparation method thereof, which adopts a composite layered structure, consisting of an outer layer of activated alumina and an inner layer of calcium oxide. This method improves the activity of the regeneration agent, and the total degradation products of the working fluid after regeneration can be controlled below 20g / L. However, the mechanical strength of the activated alumina and the problem of pore blockage caused by crystal precipitation on the surface of the activated alumina have not been effectively improved. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a method for regenerating a working fluid for producing hydrogen peroxide by an anthraquinone method, and achieves the following invention objectives: to provide a regenerating agent, the activated alumina inside of which has high stability, the pores are not easily blocked by crystallization, and the service life is long, thereby improving the regeneration effect of the working fluid.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for regenerating a working solution for producing hydrogen peroxide by an anthraquinone process comprises the following steps: The working liquid is passed into the regeneration bed to contact with the internal regeneration agent, the regeneration temperature is controlled to be 50-60°C, the contact time between the working liquid and the regeneration agent is 40-60 minutes, and then the working liquid is output to obtain the regenerated working liquid; The preparation method of the regeneration agent includes preparing modified alumina, compounding, and surface modification; The method for preparing modified alumina is as follows: adding aluminum isopropoxide and isopropanol to deionized water, stirring and hydrolyzing at 65-75° C. for 3.8-4.2 hours, then heating to 110-130° C., adding phosphoric acid, reacting for 1.5-2.5 hours to obtain alumina sol, slowly dropping the alumina sol into a double-layer solution of paraffin oil and ammonia water to form alumina microspheres, filtering and fishing out the alumina microspheres after 2.7-3.3 hours, drying at 105-115° C. for 7-9 hours, then transferring to a muffle furnace, heating to 550-650° C. at a rate of 2-4° C. / min, and calcining for 3-4 hours to obtain modified alumina; The mass ratio of deionized water, aluminum isopropoxide, isopropanol and phosphoric acid is 5-7:16.5-17.5:6-8:2.8-3.2; The stirring rate is 500-700 r / min; The alumina sol is slowly dripped, the particle size of the dripping is controlled to be 1.5-2.5 mm, and the frequency is 15-25 drops / min; The double-layer solution comprises a lower layer of ammonia water with a layer height of 4 to 6 cm and a mass fraction of ammonia water of 12 to 18%, and an upper layer of paraffin oil with a layer height of 18 to 22 cm.

[0008] The composite method comprises grinding the modified alumina, passing it through a 170-230 mesh sieve, and then adding it to a mixed solution of calcium nitrate and manganese nitrate, immersing it for 4-6 hours, and then evaporating to remove excess water, drying the obtained solid at 100-120° C. for 2.5-3.5 hours, and then calcining it at 450-550° C. for 3.6-4.4 hours to obtain a CaOMnO2 / modified alumina composite; The mass ratio of the modified aluminum oxide, calcium nitrate and manganese nitrate is 85-95:6-8:2-4; In the mixed solution of calcium nitrate and manganese nitrate, the mass fraction of calcium nitrate is 13-17%, and the mass fraction of manganese nitrate is 8-10%.

[0009] The surface modification method comprises the following steps: adding a CaOMnO2 / modified alumina composite to deionized water, stirring the composite by magnetic force for 5 to 7 hours, adding tetraethyl orthosilicate, performing ultrasonic dispersion for 0.8 to 1.2 hours, reacting the composite at room temperature for 20 to 30 hours, and then centrifuging the composite for 8 to 12 minutes. The composite is then cleaned with deionized water and ethanol, and then added to an ethylenediaminetetraacetic acid solution. 3-aminopropyltriethoxysilane is then added, and the composite is stirred at 70 to 90° C. for reaction for 3 to 4 hours, filtered, and the filter cake is dried at 50 to 70° C. to a constant weight to obtain a regeneration agent. The mass ratio of the CaOMnO2 / modified alumina composite, deionized water, and tetraethyl orthosilicate is 0.8-1.2:38-42:8-10; The mass ratio of the CaOMnO2 / modified alumina composite, ethylenediaminetetraacetic acid, and 3-aminopropyltriethoxysilane is 12-18: 3-5: 0.8-1.2; The magnetic stirring rate is 350-450 r / min, the centrifugal rate is 2500-3500 r / min, and the stirring reaction rate is 40-60 r / min; The mass fraction of the ethylenediaminetetraacetic acid solution is 20-30%.

[0010] Compared with the prior art, the present invention has the following beneficial effects: During the calcination process of conventional activated alumina, dehydration condensation occurs between adjacent hydroxyl groups to form Al-O-Al. However, during the calcination process of the modified alumina of the present invention, dehydration condensation occurs between adjacent hydroxyl groups to form Al-OPO-Al, which increases the adjacent Al 3+ The bond length between the two materials is increased, the interfacial stress is reduced, and the stability of the modified alumina is improved, making the modified alumina less likely to pulverize; A layer of silicon dioxide is coated on the surface of the modified alumina to further improve the stability of the modified alumina. At the same time, the surface of the silicon dioxide is modified by using a silane coupling agent, 3-aminopropyltriethoxysilane, to connect ethylenediaminetetraacetic acid to the silicon dioxide. The ethylenediaminetetraacetic acid can complex the metal impurities in the working solution to prevent the powdered modified alumina from entering the next process. The crystallization of some degradation products and solvent components in the working fluid will be blocked by the silica on the surface and then fixed on the surface of the regeneration agent by EDTA instead of entering the internal modified alumina pores. When the surface precipitation is aggregated, it can be removed by regular heating and dissolution, which increases the life of the regeneration agent. DETAILED DESCRIPTION

[0012] Example 1 The working liquid is passed into the regeneration bed to contact with the internal regeneration agent, the regeneration temperature is controlled to be 55°C, the contact time between the working liquid and the regeneration agent is 50 minutes, and then the working liquid is output to obtain the regenerated working liquid; The initial effective anthraquinone content of the working solution was 118.37 g / L, the total degradation product content was 50.44 g / L, the effective anthraquinone content of the working solution after regeneration was 139.82 g / L, the regeneration increment was 21.45 g / L, the total degradation product content was 28.17 g / L, and the regeneration agent life was 108 days; The preparation method of the regeneration agent includes preparing modified alumina, compounding, and surface modification; The method for preparing modified alumina is as follows: adding aluminum isopropoxide and isopropanol to deionized water, stirring and hydrolyzing at 70°C for 4 hours, then heating to 120°C, adding phosphoric acid, reacting for 2 hours to obtain alumina sol, slowly dropping the alumina sol into a double-layer solution of paraffin oil and ammonia water to form alumina microspheres, filtering and fishing out the alumina microspheres after 3 hours, drying at 110°C for 8 hours, then transferring to a muffle furnace, heating to 600°C at a rate of 3°C / min, and calcining for 3.5 hours to obtain modified alumina; The mass ratio of deionized water, aluminum isopropoxide, isopropanol, and phosphoric acid is 6:17:7:3; The stirring rate is 600r / min; The alumina sol is slowly added dropwise, the particle size is controlled to be 2 mm, and the frequency is 20 drops / min; The double-layer solution has a lower layer of ammonia water with a layer height of 5 cm and a mass fraction of ammonia water of 15%, and an upper layer of paraffin oil with a layer height of 20 cm.

[0013] The composite method comprises grinding the modified alumina, passing it through a 200-mesh sieve, and then adding it to a mixed solution of calcium nitrate and manganese nitrate, immersing it for 5 hours and then evaporating to remove excess water, drying the obtained solid at 110° C. for 3 hours, and then calcining it at 500° C. for 4 hours to obtain a CaOMnO2 / modified alumina composite; The mass ratio of the modified aluminum oxide, calcium nitrate and manganese nitrate is 90:7:3; In the mixed solution of calcium nitrate and manganese nitrate, the mass fraction of calcium nitrate is 15%, and the mass fraction of manganese nitrate is 9%.

[0014] The surface modification method comprises the following steps: adding a CaOMnO2 / modified alumina composite to deionized water, stirring magnetically for 6 hours, adding tetraethyl orthosilicate, ultrasonically dispersing for 1 hour, reacting at room temperature for 24 hours, and then centrifuging for 10 minutes, washing the precipitate with deionized water and ethanol, adding the precipitate to an ethylenediaminetetraacetic acid solution, and then adding 3-aminopropyltriethoxysilane, stirring and reacting at 80° C. for 3.5 hours, filtering, and drying the filter cake at 60° C. to a constant weight to obtain a regeneration agent; The mass ratio of the CaOMnO2 / modified alumina composite, deionized water, and tetraethyl orthosilicate is 1:40:9; The mass ratio of the CaOMnO2 / modified alumina composite, ethylenediaminetetraacetic acid, and 3-aminopropyltriethoxysilane is 15:4:1; The magnetic stirring rate is 400 r / min, the centrifugal rate is 3000 r / min, and the stirring reaction rate is 50 r / min; The mass fraction of the ethylenediaminetetraacetic acid solution is 25%.

[0015] Example 2 The working liquid is passed into the regeneration bed to contact with the internal regeneration agent, the regeneration temperature is controlled to be 50°C, the contact time between the working liquid and the regeneration agent is 40 minutes, and then the working liquid is output to obtain the regenerated working liquid; The initial effective anthraquinone content of the working solution was 118.37 g / L, the total degradation product content was 50.44 g / L, the effective anthraquinone content of the working solution after regeneration was 137.66 g / L, the regeneration increment was 19.29 g / L, the total degradation product content was 30.53 g / L, and the regeneration agent life was 103 days; The preparation method of the regeneration agent includes preparing modified alumina, compounding, and surface modification; The method for preparing modified alumina is as follows: adding aluminum isopropoxide and isopropanol to deionized water, stirring and hydrolyzing at 65° C. for 3.8 hours, then heating to 110° C., adding phosphoric acid, reacting for 1.5 hours to obtain alumina sol, slowly dropping the alumina sol into a double-layer solution of paraffin oil and ammonia water to form alumina microspheres, filtering and fishing out the alumina microspheres after 2.7 hours, drying at 105° C. for 7 hours, then transferring to a muffle furnace, heating to 550° C. at a rate of 2° C. / min, and calcining for 3 hours to obtain modified alumina; The mass ratio of deionized water, aluminum isopropoxide, isopropanol, and phosphoric acid is 5:16.5:6:2.8; The stirring rate is 500r / min; The alumina sol is slowly added dropwise, the particle size is controlled to be 1.5 mm, and the frequency is 15 drops / min; The double-layer solution has a lower layer of ammonia water with a layer height of 4 cm and a mass fraction of ammonia water of 12%, and an upper layer of paraffin oil with a layer height of 18 cm.

[0016] The composite method comprises grinding the modified alumina, passing it through a 170-mesh sieve, and then adding it to a mixed solution of calcium nitrate and manganese nitrate, immersing it for 4 hours and then evaporating to remove excess water, drying the obtained solid at 100° C. for 2.5 hours, and then calcining it at 450° C. for 3.6 hours to obtain a CaOMnO2 / modified alumina composite; The mass ratio of the modified aluminum oxide, calcium nitrate and manganese nitrate is 85:6:2; In the mixed solution of calcium nitrate and manganese nitrate, the mass fraction of calcium nitrate is 13%, and the mass fraction of manganese nitrate is 8%.

[0017] The surface modification method comprises the following steps: adding a CaOMnO2 / modified alumina composite to deionized water, stirring the composite magnetically for 5 hours, adding tetraethyl orthosilicate, performing ultrasonic dispersion for 0.8 hours, reacting the composite at room temperature for 20 hours, and then centrifuging the composite for 8 minutes. The composite is then washed with deionized water and ethanol, and then added to an ethylenediaminetetraacetic acid solution. 3-aminopropyltriethoxysilane is then added, and the composite is stirred at 70°C for reaction for 3 hours, filtered, and the filter cake is dried at 50°C to a constant weight to obtain a regeneration agent. The mass ratio of the CaOMnO2 / modified alumina composite, deionized water, and tetraethyl orthosilicate is 0.8:38:8; The mass ratio of the CaOMnO2 / modified alumina composite, ethylenediaminetetraacetic acid, and 3-aminopropyltriethoxysilane is 12:3:0.8; The magnetic stirring rate is 350 r / min, the centrifugal rate is 2500 r / min, and the stirring reaction rate is 40 r / min; The mass fraction of the ethylenediaminetetraacetic acid solution is 20%.

[0018] Example 3 The working liquid is passed into the regeneration bed to contact with the internal regeneration agent, the regeneration temperature is controlled to be 60°C, the contact time between the working liquid and the regeneration agent is 60 minutes, and then the working liquid is output to obtain the regenerated working liquid; The initial effective anthraquinone content of the working solution was 118.37 g / L, the total degradation product content was 50.44 g / L, the effective anthraquinone content of the working solution after regeneration was 134.49 g / L, the regeneration increment was 16.12 g / L, the total degradation product content was 36.25 g / L, and the regeneration agent life was 99 days; The preparation method of the regeneration agent includes preparing modified alumina, compounding, and surface modification; The method for preparing modified alumina is as follows: adding aluminum isopropoxide and isopropanol to deionized water, stirring and hydrolyzing at 75°C for 4.2 hours, then heating to 130°C, adding phosphoric acid, reacting for 2.5 hours to obtain alumina sol, slowly dropping the alumina sol into a double-layer solution of paraffin oil and ammonia water, forming alumina microspheres for 3.3 hours, filtering and fishing out the alumina microspheres, drying at 115°C for 9 hours, and then transferring to a muffle furnace, heating to 650°C at a rate of 4°C / min, and calcining for 4 hours to obtain modified alumina; The mass ratio of deionized water, aluminum isopropoxide, isopropanol, and phosphoric acid is 7:17.5:8:3.2; The stirring rate is 700r / min; The alumina sol is slowly added dropwise, the particle size is controlled to be 2.5 mm, and the frequency is 25 drops / min; The double-layer solution has a lower layer of ammonia water with a layer height of 6 cm and a mass fraction of ammonia water of 18%, and an upper layer of paraffin oil with a layer height of 22 cm.

[0019] The composite method comprises grinding the modified alumina, passing it through a 230-mesh sieve, and then adding it to a mixed solution of calcium nitrate and manganese nitrate, immersing it for 6 hours, and then evaporating to remove excess water, and drying the obtained solid at 120° C. for 3.5 hours, and then calcining it at 550° C. for 4.4 hours to obtain a CaOMnO2 / modified alumina composite; The mass ratio of the modified aluminum oxide, calcium nitrate and manganese nitrate is 95:8:4; In the mixed solution of calcium nitrate and manganese nitrate, the mass fraction of calcium nitrate is 17%, and the mass fraction of manganese nitrate is 10%.

[0020] The surface modification method comprises adding a CaOMnO2 / modified alumina composite to deionized water, stirring magnetically for 7 hours, adding tetraethyl orthosilicate, ultrasonically dispersing for 1.2 hours, reacting at room temperature for 30 hours, and then centrifuging for 12 minutes, washing the precipitate with deionized water and ethanol, adding it to an ethylenediaminetetraacetic acid solution, and then adding 3-aminopropyltriethoxysilane, stirring and reacting at 90° C. for 4 hours, filtering, and drying the filter cake at 70° C. to a constant weight to obtain a regeneration agent; The mass ratio of the CaOMnO2 / modified alumina composite, deionized water, and tetraethyl orthosilicate is 1.2:42:10; The mass ratio of the CaOMnO2 / modified alumina composite, ethylenediaminetetraacetic acid, and 3-aminopropyltriethoxysilane is 18:5:1.2; The magnetic stirring rate is 450 r / min, the centrifugal rate is 3500 r / min, and the stirring reaction rate is 60 r / min; The mass fraction of the ethylenediaminetetraacetic acid solution is 30%.

[0021] Example 4 The working liquid is passed into the regeneration bed to contact with the internal regeneration agent, the regeneration temperature is controlled to be 55°C, the contact time between the working liquid and the regeneration agent is 50 minutes, and then the working liquid is output to obtain the regenerated working liquid; The initial effective anthraquinone content of the working solution was 118.37 g / L, the total degradation product content was 50.44 g / L, the effective anthraquinone content of the working solution after regeneration was 136.51 g / L, the regeneration increment was 18.14 g / L, the total degradation product content was 30.59 g / L, and the regeneration agent life was 87 days; The preparation method of the regeneration agent includes compounding and surface modification; The composite method comprises grinding the activated alumina, passing it through a 200-mesh sieve, and then adding it to a mixed solution of calcium nitrate and manganese nitrate, immersing it for 5 hours, and then evaporating to remove excess water, drying the obtained solid at 110° C. for 3 hours, and then calcining it at 500° C. for 4 hours to obtain a CaOMnO2 / activated alumina composite; The mass ratio of the activated alumina, calcium nitrate and manganese nitrate is 90:7:3; In the mixed solution of calcium nitrate and manganese nitrate, the mass fraction of calcium nitrate is 15%, and the mass fraction of manganese nitrate is 9%.

[0022] The surface modification method comprises the following steps: adding a CaOMnO2 / activated alumina complex to deionized water, stirring the mixture magnetically for 6 hours, adding tetraethyl orthosilicate, performing ultrasonic dispersion for 1 hour, reacting the mixture at room temperature for 24 hours, and then centrifuging the mixture for 10 minutes. After the precipitate is cleaned with deionized water and ethanol, the precipitate is added to an ethylenediaminetetraacetic acid solution, and then 3-aminopropyltriethoxysilane is added. The mixture is stirred and reacted at 80° C. for 3.5 hours, filtered, and the filter cake is dried at 60° C. to a constant weight to obtain a regeneration agent. The mass ratio of the CaOMnO2 / activated alumina composite, deionized water, and tetraethyl orthosilicate is 1:40:9; The mass ratio of the CaOMnO2 / activated alumina composite, ethylenediaminetetraacetic acid, and 3-aminopropyltriethoxysilane is 15:4:1; The magnetic stirring rate is 400 r / min, the centrifugal rate is 3000 r / min, and the stirring reaction rate is 50 r / min; The mass fraction of the ethylenediaminetetraacetic acid solution is 25%.

[0023] Example 5 The working liquid is passed into the regeneration bed to contact with the internal regeneration agent, the regeneration temperature is controlled to be 55°C, the contact time between the working liquid and the regeneration agent is 50 minutes, and then the working liquid is output to obtain the regenerated working liquid; The initial effective anthraquinone content of the working solution was 118.37 g / L, the total degradation product content was 50.44 g / L, the effective anthraquinone content of the working solution after regeneration was 138.76 g / L, the regeneration increment was 20.39 g / L, the total degradation product content was 36.17 g / L, and the regeneration agent life was 104 days; The preparation method of the regeneration agent includes preparing modified alumina, compounding, and surface modification; The method for preparing modified alumina is as follows: adding aluminum isopropoxide and isopropanol to deionized water, stirring and hydrolyzing at 70°C for 4 hours, then heating to 120°C, adding phosphoric acid, reacting for 2 hours to obtain alumina sol, slowly dropping the alumina sol into a double-layer solution of paraffin oil and ammonia water to form alumina microspheres, filtering and fishing out the alumina microspheres after 3 hours, drying at 110°C for 8 hours, then transferring to a muffle furnace, heating to 600°C at a rate of 3°C / min, and calcining for 3.5 hours to obtain modified alumina; The mass ratio of deionized water, aluminum isopropoxide, isopropanol, and phosphoric acid is 6:17:7:3; The stirring rate is 600r / min; The alumina sol is slowly added dropwise, the particle size is controlled to be 2 mm, and the frequency is 20 drops / min; The double-layer solution has a lower layer of ammonia water with a layer height of 5 cm and a mass fraction of ammonia water of 15%, and an upper layer of paraffin oil with a layer height of 20 cm.

[0024] The composite method comprises grinding the modified alumina, passing it through a 200-mesh sieve, and then adding it to a mixed solution of calcium nitrate and manganese nitrate, immersing it for 5 hours and then evaporating to remove excess water, drying the obtained solid at 110° C. for 3 hours, and then calcining it at 500° C. for 4 hours to obtain a CaOMnO2 / modified alumina composite; The mass ratio of the modified aluminum oxide, calcium nitrate and manganese nitrate is 90:7:3; In the mixed solution of calcium nitrate and manganese nitrate, the mass fraction of calcium nitrate is 15%, and the mass fraction of manganese nitrate is 9%.

[0025] The surface modification method comprises adding the CaOMnO2 / modified alumina composite into deionized water, stirring magnetically for 6 hours, adding tetraethyl orthosilicate, ultrasonically dispersing for 1 hour, reacting at room temperature for 24 hours, and then centrifuging for 10 minutes, washing the precipitate with deionized water and ethanol, and drying at 60° C. to constant weight to obtain a regeneration agent; The mass ratio of the CaOMnO2 / modified alumina composite, deionized water, and tetraethyl orthosilicate is 1:40:9; The magnetic stirring speed is 400 r / min, and the centrifugal speed is 3000 r / min.

[0026] Example 6 The working liquid is passed into the regeneration bed to contact with the internal regeneration agent, the regeneration temperature is controlled to be 55°C, the contact time between the working liquid and the regeneration agent is 50 minutes, and then the working liquid is output to obtain the regenerated working liquid; The initial effective anthraquinone content of the working solution was 118.37 g / L, the total degradation product content was 50.44 g / L, the effective anthraquinone content of the working solution after regeneration was 126.15 g / L, the regeneration increment was 7.78 g / L, the total degradation product content was 40.53 g / L, and the regeneration agent life was 88 days; The preparation method of the regeneration agent includes preparing modified alumina, compounding; The method for preparing modified alumina is as follows: adding aluminum isopropoxide and isopropanol to deionized water, stirring and hydrolyzing at 70°C for 4 hours, then heating to 120°C, adding phosphoric acid, reacting for 2 hours to obtain alumina sol, slowly dropping the alumina sol into a double-layer solution of paraffin oil and ammonia water to form alumina microspheres, filtering and fishing out the alumina microspheres after 3 hours, drying at 110°C for 8 hours, then transferring to a muffle furnace, heating to 600°C at a rate of 3°C / min, and calcining for 3.5 hours to obtain modified alumina; The mass ratio of deionized water, aluminum isopropoxide, isopropanol, and phosphoric acid is 6:17:7:3; The stirring rate is 600r / min; The alumina sol is slowly added dropwise, the particle size is controlled to be 2 mm, and the frequency is 20 drops / min; The double-layer solution has a lower layer of ammonia water with a layer height of 5 cm and a mass fraction of ammonia water of 15%, and an upper layer of paraffin oil with a layer height of 20 cm.

[0027] The composite method comprises grinding the modified alumina, passing it through a 200-mesh sieve, and then adding it to a mixed solution of calcium nitrate and manganese nitrate, immersing it for 5 hours and then evaporating to remove excess water, drying the obtained solid at 110° C. for 3 hours, and then calcining it at 500° C. for 4 hours to obtain a CaOMnO2 / modified alumina composite, i.e., a regeneration agent; The mass ratio of the modified aluminum oxide, calcium nitrate and manganese nitrate is 90:7:3; In the mixed solution of calcium nitrate and manganese nitrate, the mass fraction of calcium nitrate is 15%, and the mass fraction of manganese nitrate is 9%.

[0028] In Examples 1 to 6, the testing method for the initial effective anthraquinone content of the working solution, the total degradation product content, the effective anthraquinone content of the working solution after regeneration, and the total degradation product content is gas-liquid chromatography.

[0029] Through Examples 1 to 6, it can be seen that Example 4 uses conventional activated alumina, and its regeneration effect is not much different from that of Examples 1 to 3, but conventional activated alumina is easy to pulverize, so the life of the regeneration agent is short; The regeneration effect and service life of Example 5 are not much different from those of Examples 1 to 3, but there is no complexing effect on the powdered modified alumina. After regeneration, the working liquid contains a small amount of powdered modified alumina particles, which increases the separation burden of the next process. Example 6 Since the surface of the regeneration agent lacks the protection of silicon dioxide and the fixation of the crystals, the regeneration agent is easily blocked by the crystals, the regeneration effect on the working fluid is poor, and the life of the regeneration agent is short.

Claims

1. A method for regenerating a working solution for producing hydrogen peroxide by anthraquinone method, characterized in that: The regeneration method is to pass the working fluid into the regeneration bed, contact with the internal regeneration agent for a period of time, and then output the working fluid to obtain the regenerated working fluid; The preparation method of the regeneration agent includes preparing modified alumina, compounding, and surface modification; The method for preparing modified alumina comprises adding aluminum isopropoxide and isopropanol to deionized water, hydrolyzing for 3.8 to 4.2 hours, then heating to 110 to 130° C., adding phosphoric acid, reacting for 1.5 to 2.5 hours to obtain an alumina sol, slowly dropping the alumina sol into a double-layer solution of paraffin oil and ammonia water to form alumina microspheres, and after 2.7 to 3.3 hours, filtering and removing the alumina microspheres, drying and transferring them to a muffle furnace, and calcining for 3 to 4 hours to obtain modified alumina; The surface modification method comprises the following steps: adding a CaOMnO2 / modified alumina complex to deionized water, magnetically stirring for 5 to 7 hours, adding tetraethyl orthosilicate, ultrasonically dispersing for 0.8 to 1.2 hours, reacting at room temperature for 20 to 30 hours, and then centrifuging for 8 to 12 minutes. After the precipitate is cleaned with deionized water and ethanol, it is added to an ethylenediaminetetraacetic acid solution, and then 3-aminopropyltriethoxysilane is added. The reaction is stirred at 70 to 90° C. for 3 to 4 hours, and the regeneration agent is obtained by filtering and drying.

2. The method for regenerating a working solution for producing hydrogen peroxide by anthraquinone process according to claim 1, characterized in that: The contact time of the regeneration agent is 40 to 60 minutes, and the contact regeneration temperature is 50 to 60°C.

3. The method for regenerating a working solution for producing hydrogen peroxide by anthraquinone process according to claim 1, characterized in that: In the method for preparing modified alumina, the mass ratio of deionized water, aluminum isopropoxide, isopropanol and phosphoric acid is 5-7:16.5-17.5:6-8:2.8-3.2, and the alumina sol is slowly added dropwise, the dropwise particle size is controlled to be 1.5-2.5 mm, and the frequency is 15-25 drops / min.

4. The method for regenerating a working solution for producing hydrogen peroxide by anthraquinone process according to claim 1, characterized in that: In the method for preparing modified alumina, the double-layer solution has a lower layer of ammonia water with a layer height of 4 to 6 cm and a mass fraction of ammonia water of 12 to 18%, and an upper layer of paraffin oil with a layer height of 18 to 22 cm.

5. The method for regenerating a working solution for producing hydrogen peroxide by anthraquinone method according to claim 1, characterized in that: In the surface modification method, the mass ratio of the CaOMnO2 / modified alumina composite, deionized water, and tetraethyl orthosilicate is 0.8-1.2:38-42:8-10, the mass ratio of the CaOMnO2 / modified alumina composite, ethylenediaminetetraacetic acid, and 3-aminopropyltriethoxysilane is 12-18:3-5:0.8-1.2, the magnetic stirring rate is 350-450 r / min, the centrifugal rate is 2500-3500 r / min, the stirring reaction rate is 40-60 r / min, and the mass fraction of the ethylenediaminetetraacetic acid solution is 20-30%.

6. The method for regenerating a working solution for producing hydrogen peroxide by anthraquinone method according to claim 1, characterized in that: The composite method comprises grinding the modified alumina, passing it through a 170-230 mesh sieve, and then adding it into a mixed solution of calcium nitrate and manganese nitrate, immersing it for 4-6 hours, evaporating and removing excess water, and drying and calcining the obtained solid to obtain a CaOMnO2 / modified alumina composite.

7. The method for regenerating a working solution for producing hydrogen peroxide by anthraquinone method according to claim 6, characterized in that: In the composite method, the mass ratio of the modified aluminum oxide, calcium nitrate and manganese nitrate is 85-95:6-8:2-4, and in the mixed solution of calcium nitrate and manganese nitrate, the mass fraction of calcium nitrate is 13-17%, and the mass fraction of manganese nitrate is 8-10%.

8. The method for regenerating a working solution for producing hydrogen peroxide by anthraquinone method according to claim 6, characterized in that: In the composite method, the calcination temperature is 450-550° C. and the calcination time is 3.6-4.4 hours.