Method for preparing high-concentration hydrogen peroxide

Abstract

The invention relates to the technical field of hydrogen peroxide production, and discloses a method for preparing high-concentration hydrogen peroxide, which comprises the following steps: fully mixing low-concentration hydrogen peroxide with the concentration of 34-42wt% with an oxidation liquid with higher hydrogen peroxide content after precision filtration, and dissolving part of hydrogen peroxide in the oxidation liquid into the low-concentration hydrogen peroxide in the mixing process, the method comprises the following steps of: firstly, separating an oil phase from a water phase through a separator to obtain a high-concentration hydrogen peroxide crude product with the concentration of 48-56wt%, and separating to remove organic matters entrained in the high-concentration hydrogen peroxide crude product to obtain a high-concentration hydrogen peroxide finished product with the concentration close to 50wt%. The high-concentration hydrogen peroxide with the concentration close to 50 wt% can be prepared without a concentration process, the production cost of the high-concentration hydrogen peroxide can be reduced, and the process safety can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen peroxide production, and in particular to a method for preparing high-concentration hydrogen peroxide. Background Art

[0002] Hydrogen peroxide is an ideal green chemical, widely used in many fields such as papermaking, textiles, chemical manufacturing, environmental protection, electronics, etc. my country is the world's largest producer and consumer of hydrogen peroxide. Although there are many methods for preparing hydrogen peroxide, the anthraquinone method is the only method for large-scale industrial production of hydrogen peroxide. This method uses alkyl anthraquinone dissolved in an organic solvent as a carrier for hydrogenation and oxidation, and obtains hydrogen peroxide through hydrogenation, oxidation, extraction and post-treatment. Anthraquinone is used as a working carrier for recycling, and is reduced to hydroanthraquinone during the hydrogenation process. Hydroanthraquinone is oxidized to generate anthraquinone during the oxidation process, and hydrogen peroxide is obtained at the same time. The hydrogen peroxide dissolved in the working solution is extracted with water to obtain a hydrogen peroxide product. Because hydrogen peroxide and water can be miscible in any proportion, hydrogen peroxide products of different concentrations can be prepared. However, due to various factors, the concentration of hydrogen peroxide extracted by the current hydrogen peroxide production technology is difficult to exceed 38wt%, generally between 27.5wt% and 36wt%, among which the two concentrations of 27.5wt% and 35wt% are the most used in industry.

[0003] Due to the characteristics of hydrogen peroxide being easy to decompose and release oxygen under the action of anthraquinone hydrogenation catalyst, in order to prevent the oxygen produced by the decomposition of hydrogen peroxide from mixing with a large amount of hydrogen in the hydrogenation reactor to cause a safety accident, it is necessary to control the hydrogen peroxide content in the working liquid entering the hydrogenation reactor. In actual production, the hydrogen peroxide content in the working liquid (i.e., the raffinate) exiting the extraction tower is controlled, that is, the raffinate index shall not be higher than 0.3g / L. If it exceeds this index, emergency parking treatment is required, otherwise there is a large safety hazard. Therefore, the hydrogen peroxide extraction process requires not only to ensure that the raffinate does not exceed the standard, but also to ensure the concentration of hydrogen peroxide produced by extraction. Affected by the distribution coefficient of hydrogen peroxide in the aqueous phase and the working liquid and the design of the extraction tower, in order to ensure that the raffinate does not exceed the standard, the concentration of hydrogen peroxide produced by direct extraction is restricted. Under normal circumstances, when a fixed bed process is used to produce hydrogen peroxide, the concentration of hydrogen peroxide obtained by extraction is almost below 35wt%. If this concentration is exceeded, it is easy to cause the raffinate to be high, which poses a large safety hazard. When using the fluidized bed process to produce hydrogen peroxide, the hydrogenation efficiency and oxidation efficiency are higher than those of the fixed bed process. Although the concentration of hydrogen peroxide produced by extraction can stably reach 35wt%, the raffinate generally reaches 0.2g / L at this time. If the concentration of hydrogen peroxide is further increased, the raffinate will inevitably increase. Therefore, due to the limitation of the working fluid system and safety production considerations, in the current hydrogen peroxide production technology, the concentration of hydrogen peroxide produced by extraction is difficult to exceed 38wt%.

[0004] Compared with hydrogen peroxide with a concentration of 27.5-35wt%, hydrogen peroxide with a concentration close to 50wt% not only has stronger oxidation ability, but is also easy to transport. High-concentration hydrogen peroxide has many uses in industry, such as the production of propylene oxide or epichlorohydrin, which must be used. When cyclohexanone ammoximation is used to produce cyclohexanone oxime, the use of high-concentration hydrogen peroxide can not only improve the reaction efficiency, but also reduce wastewater discharge. With the increasing requirements for environmental protection, the use of high-concentration hydrogen peroxide will inevitably increase.

[0005] At present, the industry obtains hydrogen peroxide with a concentration of 27.5-35wt% through hydrogenation, oxidation and extraction, and then concentrates it to obtain a high-concentration hydrogen peroxide product with a concentration of about 50wt% or even higher, such as patent CN103523756A. Usually, falling film evaporation is used for concentration, which not only requires equipment such as falling film evaporator and vacuum pump, but also requires high energy consumption because water is evaporated during concentration. In addition, the hydrogen peroxide will accelerate decomposition when heated during the concentration process, resulting in loss of hydrogen peroxide material. Summary of the invention

[0006] In order to solve the technical problems mentioned in the background technology that the equipment required for industrial preparation of hydrogen peroxide with a concentration of 50wt% or more is relatively expensive and the energy consumption is too high, and at the same time, evaporation and concentration may lead to the loss of hydrogen peroxide materials, the present invention provides a method for preparing high-concentration hydrogen peroxide, which can achieve the preparation of high-concentration hydrogen peroxide with a concentration close to 50wt% without a concentration process, which can not only reduce the production cost of high-concentration hydrogen peroxide, but also improve process safety.

[0007] The specific technical scheme of the present invention is: a method for preparing high-concentration hydrogen peroxide, comprising the following steps: a) subjecting the working liquid to a hydrogenation reaction to obtain a hydrogenated liquid, oxidizing and filtering to obtain a first oxidized liquid, wherein the hydrogen peroxide content in the first oxidized liquid is 12.5 to 20.0 g / L; b) fully mixing the first oxidation liquid with low-concentration hydrogen peroxide and then performing water-oil phase separation, the oil phase obtained by separation is the second oxidation liquid, the water phase obtained is a high-concentration hydrogen peroxide crude product, and the concentration of the low-concentration hydrogen peroxide mixed with the first oxidation liquid is 34-42wt%; c) countercurrent extraction of the second oxidation liquid with weakly acidic water to obtain low-concentration hydrogen peroxide, and the low-concentration hydrogen peroxide is mixed with the first oxidation liquid in step b); d) cooling the crude high-concentration hydrogen peroxide product, performing agglomeration separation and gas stripping to obtain a high-concentration hydrogen peroxide product with a concentration of 48-56 wt %.

[0008] The present invention proposes a new process: a low-concentration hydrogen peroxide with a concentration of 34-42wt% and a stability of not less than 97.5% is fully mixed with an oxidizing liquid with a high hydrogen peroxide content after precision filtration. During the mixing process, part of the hydrogen peroxide in the oxidizing liquid will dissolve into the low-concentration hydrogen peroxide, thereby achieving the concentration of the low-concentration hydrogen peroxide. Then, the oil phase and the water phase are separated by a separator to obtain a high-concentration hydrogen peroxide crude product with a concentration of 48-56wt%. The organic matter carried therein is then separated and removed to obtain a high-concentration hydrogen peroxide finished product with a concentration close to 50wt%. The oil phase material separated from the separator, i.e., the second oxidizing liquid, is sent to an extraction tower, and the hydrogen peroxide dissolved therein is extracted into the water phase with weakly acidic water, and a low-concentration hydrogen peroxide with a concentration of 34-42wt% is obtained from the bottom of the tower, and then it is pumped to the front of the oxidizing liquid pump by a rare product pump to merge with the first oxidizing liquid. The hydrogen peroxide content in the raffinate obtained from the upper part of the extraction tower is controlled to be no higher than 0.25g / L to ensure extraction safety. The raffinate from the extraction tower is treated by conventional methods to remove water and then returned to the hydrogenation reactor to continue the hydrogenation reaction, thus realizing the recycling of the working liquid.

[0009] Furthermore, in step a), the working solution is obtained by dissolving ethyl anthraquinone and amyl anthraquinone or amyl anthraquinone in a solvent, and the solvent is a mixed solvent composed of non-polar heavy aromatic hydrocarbons and polar solvents such as tetrabutyl urea, diisobutyl carbinol and / or trioctyl phosphate, methyl cyclohexyl acetate. The use of a variety of solvents can improve the solubility of anthraquinone and hydroanthraquinone, providing a prerequisite for obtaining an oxidizing solution with a high hydrogen peroxide content.

[0010] Furthermore, the concentration of anthraquinone in the working fluid is 150 to 360 kg / m 3 .

[0011] Furthermore, the volume ratio of the non-polar solvent to the polar solvent in the working solution is 60:40 to 85:15.

[0012] Preferably, after the working fluid is hydrogenated, the hydrogenation efficiency can reach 13.0 to 20.5 g / L.

[0013] Further, the oxidation is carried out in an oxidation reactor, using air to oxidize the hydrogenated liquid.

[0014] Preferably, the first oxidizing liquid needs to be finely filtered before entering the next step to remove possible entrained solid particle impurities, prevent the solid particle impurities from causing drastic decomposition of high-concentration hydrogen peroxide, and improve process safety.

[0015] Preferably, during precision filtration, the filter element precision is 0.5 to 5 μm, and the interception efficiency is ≥ 99.8%.

[0016] Furthermore, in step b), the concentration of the low-concentration hydrogen peroxide is 34-42 wt %, and the stability is ≥97.5%.

[0017] Furthermore, the concentration of the crude high-concentration hydrogen peroxide is 48-56wt%, and the stability is ≥97.0%.

[0018] Furthermore, in step b), the content of hydrogen peroxide in the second oxidation solution is 6.5-12.0 g / L.

[0019] Furthermore, the first oxidizing liquid and the low-concentration hydrogen peroxide solution can be fully mixed in two ways.

[0020] The first method: The first oxidation liquid and low-concentration hydrogen peroxide are combined in front of the oxidation liquid pump, pre-mixed by a centrifugal pump, and then further mixed in a mixer such as a jet pump or a static mixer. One to three mixers are used in series to ensure the mixing effect. If the low-concentration hydrogen peroxide is not thoroughly mixed with the first oxidation liquid, it is difficult to obtain a high-concentration hydrogen peroxide product.

[0021] The second method: the first oxidizing liquid and low-concentration hydrogen peroxide are simultaneously fed into a stirring kettle and fully mixed by stirring under a nitrogen atmosphere.

[0022] Preferably, the first method is adopted for mixing.

[0023] Preferably, the water-oil separation is carried out in a separator, and the separator is selected from at least one of a static separation tank, a centrifuge, a centrifugal extractor, a decanter or a coalescing separator, and 1 to 3 separators are used in series to ensure the water-oil separation effect. If the water phase and the oil phase are not separated thoroughly, the hydrogen peroxide content in the second oxidation liquid will be too high, resulting in excessive residual content in the working liquid after extraction, affecting safe production. In addition, it will also cause the total organic carbon content in the crude hydrogen peroxide to be too high, and even after subsequent purification, it is likely to affect the quality of the high-concentration hydrogen peroxide product.

[0024] Furthermore, in step c), the weakly acidic water is an aqueous solution with a phosphoric acid concentration of 0.1 to 0.4 g / L.

[0025] Furthermore, in step c), the volume ratio of the second oxidizing liquid to the weakly acidic water is 45:1 to 85:1.

[0026] Furthermore, in step d), the cooling temperature is 25-40°C.

[0027] Preferably, the extraction is carried out in an extraction tower with weakly acidic water, and the second oxidation liquid enters from the bottom of the extraction tower and countercurrently extracts with the weakly acidic water added from the top of the tower, so that the hydrogen peroxide in the second oxidation liquid is extracted into the water phase, and low-concentration hydrogen peroxide is produced from the bottom of the tower, and then pumped to the front of the oxidation liquid pump with a rare product to merge with the first oxidation liquid. The working liquid coming out of the upper part of the extraction tower is pre-separated from part of the water by the oil-water separation filler arranged at the upper part of the extraction tower, and then enters the dewatering system, and returns to the hydrogenation reactor after dewatering. During extraction, the residual should be controlled not to exceed 0.25g / L, which is lower than the control index of the existing process not higher than 0.30g / L, and is therefore more conducive to safe production. In order to ensure the concentration of low-concentration hydrogen peroxide produced by extraction, the hydrogen peroxide content in the second oxidation liquid cannot be too low, otherwise the required concentration of low-concentration hydrogen peroxide cannot be obtained, and it is difficult to obtain the required concentration of high-concentration hydrogen peroxide.

[0028] In order to ensure that the residual does not exceed the safety control index of 0.25g / L and to obtain low-concentration hydrogen peroxide with a higher concentration as much as possible, the extraction tower must have a certain number of plates. In order to ensure the stability of low-concentration hydrogen peroxide and high-concentration hydrogen peroxide, weakly acidic water with a phosphoric acid concentration of 0.1-0.4g / L is used as the extraction agent.

[0029] Preferably, the height-to-diameter ratio of the extraction tower is 5:1 to 9.5:1, and the number of tower plates is 24 to 56. A wire mesh filler composited with stainless steel and PP or stainless steel and PTFE is arranged under each tower plate to enhance the extraction effect and ensure that the concentration of low-concentration hydrogen peroxide and the residual index of the raffinate can meet the requirements. A low-concentration hydrogen peroxide separation stationary section is arranged at the bottom of the extraction tower to minimize the entrainment of the working liquid with the low-concentration hydrogen peroxide, and the height of the stationary section is 1.5 to 4.5 meters.

[0030] Furthermore, in step d), during the gas stripping, the air before entering the oxidation reactor is used for gas stripping, and the air after use is returned to the oxidation reactor, so that there is no material loss during the gas stripping process. The total organic carbon content is further reduced by gas stripping to ensure that the total organic carbon content of the high-concentration hydrogen peroxide product meets the standard.

[0031] Preferably, the gas stripping is carried out in a gas stripping tower. The height-to-diameter ratio of the gas stripping tower is 3.5:1-8:1; the operating pressure of the gas stripping tower is 0.5-1.0 MPaG; the volume ratio of the high-concentration hydrogen peroxide entering the gas stripping tower to the air is 1:20-1:65; the packing is a stainless steel structured packing or a ball ring, a step ring, a conjugate ring, or a saddle ring random packing. If the air intake is too low, the purpose of effectively reducing the total organic carbon content in the hydrogen peroxide cannot be achieved; if the air intake is too large, the residence time of the hydrogen peroxide will be too short or even atomized, and the gas stripping effect cannot be achieved.

[0032] Preferably, the mixing and separation operation temperature is 48-53°C.

[0033] Preferably, the extraction operating temperature is 48-53°C.

[0034] Preferably, the operating temperature of the coalescence separation and gas stripping is 25-40°C.

[0035] Preferably, the residence time of the coalescence separation is 2 to 15 minutes.

[0036] Preferably, the material of the coalescing separation filter element is one or more of ethylene-tetrafluoroethylene copolymer, fluorinated ethylene propylene copolymer, soluble polytetrafluoroethylene, polyvinylidene fluoride or polyphenylene sulfide.

[0037] Compared with the prior art, the beneficial effects of the present invention are: 1) By fully mixing low-concentration hydrogen peroxide with an oxidizing liquid with a high hydrogen peroxide content, and then performing oil-water separation, a high-concentration hydrogen peroxide crude product can be obtained, and then the organic matter carried therein is separated and removed to obtain a high-concentration hydrogen peroxide finished product. Compared with the preparation of high-concentration hydrogen peroxide by concentration, the method of the present invention is relatively simple, the hydrogen peroxide is always at a lower operating temperature, not only the production process is safer and more reliable, but also energy consumption is reduced.

[0038] 2) A highly efficient working liquid system is used, the hydrogenation efficiency of the working liquid during the hydrogenation reaction is not less than 13.0 g / L, and the hydrogen peroxide content in the oxidation liquid is not less than 12.5 g / L. Compared with the technology of 7-9 g / L of fixed bed or 10-12 g / L of conventional fluidized bed hydrogenation efficiency, when the production scale of the hydrogen peroxide device is the same, the working liquid circulation volume of the present invention is lower and the production efficiency is higher.

[0039] 3) A method combining coagulation separation and gas stripping is used to remove organic matter entrained in crude hydrogen peroxide. Compared with the traditional method of purifying hydrogen peroxide with heavy aromatic hydrocarbons, the contact between heavy aromatic hydrocarbons and hydrogen peroxide is avoided, thereby improving production safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the process flow of the present invention.

[0041] The accompanying drawings are marked as follows: 1. oxidation reactor; 2. precision filter; 3. oxidation liquid storage tank; 4. oxidation liquid pump; 5. mixer; 6. separator; 7. extraction tower; 8. rare product temporary storage tank; 9. rare product pump; 10. cooler; 11. coarse product agglomerator; 12. concentrated product temporary storage tank; 13. concentrated product pump; 14. gas stripping tower; 15. extraction tower plate; 16. oil-water separation filler; 17. high-concentration hydrogen peroxide finished product; 18. air; 19. water removal system. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the embodiments.

[0043] Overall embodiment like Figure 1 As shown, a method for preparing high-concentration hydrogen peroxide comprises the following steps:

[0044] 1) Hydrogenation The working liquid is subjected to a hydrogenation reaction in a hydrogenation reactor, and the obtained hydrogenated liquid is filtered and then enters an oxidation reactor 1, where an oxidation liquid is obtained after an oxidation reaction. The oxidation liquid is filtered through a precision filter 2 to obtain a first oxidation liquid, which enters an oxidation liquid storage tank 3.

[0045] Specifically, the filter element in the precision filter 1 has a precision of 1 μm and a retention efficiency of 99.9%.

[0046] 2) Two-phase separation The first oxidizing liquid is delivered to the mixer 5 by the oxidizing liquid pump 4, and enters the mixer 5 together with the low-concentration hydrogen peroxide delivered from the rare product pump 9 through the oxidizing liquid pump 4 to be fully mixed, and then enters the separator 6 for two-phase separation, wherein the water phase is the high-concentration hydrogen peroxide crude product, and the oil phase is the second oxidizing liquid.

[0047] Specifically, the operating temperature of the mixer 5 and the separator 6 is 50°C.

[0048] Specifically, the concentration of the low-concentration hydrogen peroxide is 34-42wt%, and the stability is ≥97.5%.

[0049] Specifically, the concentration of the crude high-concentration hydrogen peroxide is 48-56wt%, and the stability is ≥97.0%.

[0050] Specifically, the content of hydrogen peroxide in the second oxidizing liquid is 6.5-12.0 g / L.

[0051] Specifically, the first oxidizing liquid and the low-concentration hydrogen peroxide solution are further mixed in the mixer 4 .

[0052] In particular, the mixer is a static mixer.

[0053] Specifically, the water phase and oil phase separation are carried out in the separator 6, and two separators 6 are used in series.

[0054] Specifically, the separator is a static separation tank and a coalescing separator used in series.

[0055] 3) Countercurrent extraction The second oxidizing liquid is sent to the extraction tower 7, and countercurrent extraction is performed with a phosphoric acid aqueous solution with an acidity of 0.15 g / L. The hydrogen peroxide is dissolved in the water phase and extracted from the bottom of the tower to obtain a low-concentration hydrogen peroxide solution, which enters the rare product temporary storage tank 8. Thereafter, it is sent to the oxidizing liquid pump 4 by the rare product pump 9 to merge with the first oxidizing liquid. The remaining working liquid is taken out from the top of the tower, and after coalescence, separation and water removal, it is returned to the hydrogenation reactor for recycling.

[0056] Specifically, in all embodiments and comparative examples, the residue did not exceed the safety control index of 0.25 g / L.

[0057] Specifically, countercurrent extraction is carried out in the extraction tower 7, wherein the height-to-diameter ratio of the extraction tower 7 is 7.5:1, the number of tower plates is 36, a wire mesh separation filler composite of stainless steel and PTFE is arranged below the tower plate 15, an oil-water separation filler 16 is arranged at the upper part of the extraction tower, and a low-concentration hydrogen peroxide separation standing section is arranged at the lower part of the extraction tower, and the height of the standing section is 2.0 meters.

[0058] Specifically, the operating temperature of the extraction column is 50°C.

[0059] Specifically, the total organic carbon content in the crude high-concentration hydrogen peroxide product is ≤0.025 wt %.

[0060] Specifically, the raffinate discharged from the upper part of the extraction tower 7 enters the water removal system 19 .

[0061] 4) Refining After the high-concentration crude hydrogen peroxide is cooled to 35°C by the cooler 10, it enters the crude hydrogen peroxide agglomerator 11 for agglomeration and separation, and then enters the concentrated product temporary storage tank 12, and is finally transported to the stripping tower 14 by the concentrated product pump 13. The air 18 before entering the oxidation reactor is used for stripping to obtain a high-concentration hydrogen peroxide product 17, and the air after stripping is returned to the oxidation reactor 1.

[0062] Specifically, the gas stripping tower 13 has a height-to-diameter ratio of 6:1 and an operating pressure of 0.6 MPaG.

[0063] Specifically, the gas stripping tower is a packed tower, and the packing is stainless steel structured packing.

[0064] Specifically, the operating temperature of the crude product coalescer 11 and the stripping column 13 was 35°C.

[0065] Specifically, the residence time of the crude hydrogen peroxide in the crude product agglomerator 11 is 6 minutes.

[0066] Specifically, the crude product coalescer 11 is made of ethylene-tetrafluoroethylene copolymer.

[0067] Example 1 1) Hydrogenation The working liquid is hydrogenated to obtain a hydrogenated liquid, which is oxidized and filtered to obtain a first oxidized liquid, wherein the content of hydrogen peroxide in the first oxidized liquid is 15.2 g / L.

[0068] Specifically, the working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate as a mixed solvent, wherein the anthraquinone concentration is 220 kg / m 3 .

[0069] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate is 68:18:12:2.

[0070] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 15.6 g / L.

[0071] 2) Two-phase separation The first oxidation liquid is fully mixed with low-concentration hydrogen peroxide and then separated into an aqueous phase and an oil phase. The oil phase obtained by separation is the second oxidation liquid, and the aqueous phase obtained is a crude product of high-concentration hydrogen peroxide.

[0072] Specifically, the hydrogen peroxide content in the second oxidation liquid is 8.8 g / L.

[0073] The concentration of the crude high-concentration hydrogen peroxide is 50.4wt% and the stability is 97.5%.

[0074] 3) Extraction The second oxidizing liquid was countercurrently extracted with 0.15 g / L phosphoric acid aqueous solution to obtain low-concentration hydrogen peroxide, which was mixed with the first oxidizing liquid in step 2), and the residue was detected to be 0.16 g / L.

[0075] Specifically, the volume ratio of the second oxidizing liquid to the weakly acidic water is 68:1.

[0076] Specifically, the concentration of the low-concentration hydrogen peroxide is 37.3 wt % and the stability is 97.9%.

[0077] 4) Refining The high-concentration hydrogen peroxide crude product is cooled and then subjected to agglomeration separation and gas stripping to obtain a high-concentration hydrogen peroxide finished product.

[0078] The hydrogen peroxide content in the high-concentration hydrogen peroxide product is 50.4wt%.

[0079] Specifically, the temperature of the coalescence separation was 35°C.

[0080] Specifically, the residence time for the coalescence separation was 6 min.

[0081] Specifically, the operating temperature of the gas stripping is 35°C.

[0082] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0083] 5) Detection It was detected that the total organic carbon content in the crude high-concentration hydrogen peroxide was 0.023wt%, the total organic content decreased to 0.021wt% after agglomeration and separation, and the total organic carbon content in the high-concentration hydrogen peroxide finished product obtained after gas stripping was 0.019wt%. It can be seen that the total organic content in hydrogen peroxide is continuously reduced as the process (agglomeration and separation, gas stripping) proceeds. Compared with the traditional method of purifying hydrogen peroxide with heavy aromatic hydrocarbons, the contact between heavy aromatic hydrocarbons and hydrogen peroxide is avoided, and the production safety is improved.

[0084] Comparative Example 1 The difference between this comparative example and Example 1 is that in step 1) of this comparative example, the content of hydrogen peroxide in the first oxidation solution is 10.8 g / L, that is, when the concentration of hydrogen peroxide in the first oxidation solution is lower than 12.5 g / L, the rest of the process is the same as that of Example 1, and the specific steps are as follows: 1) Hydrogenation The working liquid is hydrogenated to obtain a hydrogenated liquid, which is oxidized and filtered to obtain a first oxidized liquid, wherein the content of hydrogen peroxide in the first oxidized liquid is 10.5 g / L.

[0085] Specifically, the working liquid uses amyl anthraquinone as a working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate. Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea and methyl cyclohexyl acetate is 68:18:12:2.

[0086] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 10.8 g / L.

[0087] 2) Two-phase separation The first oxidation liquid is fully mixed with low-concentration hydrogen peroxide and then separated into an aqueous phase and an oil phase. The oil phase obtained by separation is the second oxidation liquid, and the aqueous phase obtained is a crude hydrogen peroxide product with an increased concentration.

[0088] Specifically, the hydrogen peroxide content in the second oxidizing liquid is 6.2 g / L.

[0089] The concentration of the crude hydrogen peroxide with increased concentration is 42.5 wt % and the stability is 97.7%.

[0090] 3) Countercurrent extraction The second oxidizing liquid was countercurrently extracted with a 0.15 g / L phosphoric acid aqueous solution to obtain a low-concentration hydrogen peroxide solution, which was mixed with the first oxidizing liquid in step 2), and the residue was detected to be 0.13 g / L.

[0091] Specifically, the volume ratio of the second oxidizing liquid to the weakly acidic water is 68:1.

[0092] Specifically, the concentration of the low-concentration hydrogen peroxide is 30.8 wt % and the stability is 98.3%.

[0093] 4) Refining The crude hydrogen peroxide with increased concentration obtained in step 2) is cooled, subjected to agglomeration separation and gas stripping to obtain a finished hydrogen peroxide product.

[0094] The hydrogen peroxide content in the finished hydrogen peroxide solution is 42.5wt%.

[0095] Specifically, the temperature of the coalescence separation was 35°C.

[0096] Specifically, the residence time for the coalescence separation was 6 min.

[0097] Specifically, the temperature of the gas stripping was 35°C.

[0098] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0099] 5) Detection It was detected that the total organic carbon content in the crude hydrogen peroxide was 0.023wt%, the total organic content in the crude hydrogen peroxide after agglomeration and separation decreased to 0.021wt%, and the total organic carbon content in the finished hydrogen peroxide obtained after gas stripping was 0.019wt%.

[0100] Table 1 Effect of hydrogen peroxide content in the first oxidation solution on the concentration of hydrogen peroxide finished product It can be seen from the data in Table 1 that when the hydrogenation efficiency is reduced and the hydrogen peroxide content in the first oxidation liquid is too low, it will directly lead to a decrease in the concentration of low-concentration hydrogen peroxide and the concentration of high-concentration hydrogen peroxide. The higher the hydrogen peroxide content in the first oxidation liquid, the higher the concentration of hydrogen peroxide that can be produced. When the hydrogen peroxide content in the first oxidation liquid is low, a hydrogen peroxide product with a concentration close to 50wt% cannot be produced.

[0101] Comparative Example 2 The difference between this comparative example and Example 1 is that in this comparative example, in step 3), the concentration of the low-concentration hydrogen peroxide is 32.7%, that is, when the concentration of the low-concentration hydrogen peroxide is less than 34wt%, the concentration of the hydrogen peroxide product finally obtained is compared. The remaining steps are the same as those in Example 1, and the specific steps are as follows: 1) Hydrogenation The working liquid is hydrogenated to obtain a hydrogenated liquid, which is oxidized and filtered to obtain a first oxidized liquid, wherein the content of hydrogen peroxide in the first oxidized liquid is 15.2 g / L.

[0102] Specifically, the working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate as a mixed solvent, wherein the anthraquinone concentration is 220 kg / m 3 .

[0103] Specifically, the volume ratio of heavy aromatics, tetrabutyl urea, diisobutyl carbinol and is 68:18:12:2.

[0104] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 15.6 g / L.

[0105] 2) Two-phase separation The first oxidation liquid is fully mixed with low-concentration hydrogen peroxide and then separated into an aqueous phase and an oil phase. The oil phase obtained by separation is the second oxidation liquid, and the aqueous phase obtained is a crude hydrogen peroxide product with an increased concentration.

[0106] Specifically, the hydrogen peroxide content in the second oxidation liquid is 8.3 g / L.

[0107] The concentration of the crude hydrogen peroxide is 46.7wt% and the stability is 97.4%.

[0108] 3) Countercurrent extraction The second oxidizing liquid was countercurrently extracted with 0.15 g / L phosphoric acid aqueous solution to obtain low-concentration hydrogen peroxide, which was mixed with the first oxidizing liquid in step 2), and the residue was detected to be 0.14 g / L.

[0109] Specifically, the volume ratio of the second oxidizing liquid to the weakly acidic water is 58:1.

[0110] Specifically, the concentration of the low-concentration hydrogen peroxide is 32.7 wt % and the stability is 97.8%.

[0111] 4) Refining The crude hydrogen peroxide is cooled and then subjected to agglomeration separation and gas stripping to obtain the finished hydrogen peroxide product.

[0112] The hydrogen peroxide content in the finished hydrogen peroxide solution is 46.7wt%.

[0113] Specifically, the temperature of the coalescence separation was 35°C.

[0114] Specifically, the residence time for the coalescence separation was 6 min.

[0115] Specifically, the temperature of the gas stripping was 35°C.

[0116] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0117] 5) Detection It was detected that the total organic carbon content in the crude hydrogen peroxide was 0.023wt%, which further decreased to 0.021wt% after agglomeration and separation, and the total organic carbon content in the finished hydrogen peroxide obtained after gas stripping was 0.019wt%.

[0118] Table 2 Effect of low concentration hydrogen peroxide concentration on the concentration of finished hydrogen peroxide It can be concluded from the data in Table 2 that a decrease in the concentration of the low-concentration hydrogen peroxide produced by extraction will lead to a decrease in the hydrogen peroxide content in the subsequent second oxidation liquid and the concentration of the hydrogen peroxide product. When the concentration of the low-concentration hydrogen peroxide is low, a hydrogen peroxide product with a concentration close to 50wt% cannot be produced.

[0119] Comparative Example 3 The difference between this comparative example and Example 1 is that in this comparative example, in step 2), the first oxidizing liquid does not pass through the mixer after passing through the oxidizing liquid pump, but directly enters the separator, and the specific steps are: 1) Hydrogenation The working liquid is hydrogenated to obtain a hydrogenated liquid, which is oxidized and filtered to obtain a first oxidized liquid, wherein the content of hydrogen peroxide in the first oxidized liquid is 15.2 g / L.

[0120] Specifically, the working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate as a mixed solvent, wherein the anthraquinone concentration is 220 kg / m 3 .

[0121] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate is 68:18:12:2.

[0122] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 15.6 g / L.

[0123] 2) Two-phase separation After the first oxidizing liquid and low-concentration hydrogen peroxide are premixed by the oxidizing liquid pump, they do not pass through the mixer but directly enter the separator for water-oil phase separation. The separated oil phase is the second oxidizing liquid, and the obtained water phase is the crude hydrogen peroxide with increased concentration.

[0124] Specifically, the hydrogen peroxide content in the second oxidation liquid is 9.5 g / L.

[0125] The concentration of the crude hydrogen peroxide is 45.6wt% and the stability is 97.5%.

[0126] 3) Extraction The second oxidizing liquid was countercurrently extracted with 0.15 g / L phosphoric acid aqueous solution to obtain low-concentration hydrogen peroxide, which was mixed with the first oxidizing liquid in step 2), and the residue was detected to be 0.14 g / L.

[0127] Specifically, the volume ratio of the second oxidizing liquid to the weakly acidic water is 68:1.

[0128] Specifically, the concentration of the low-concentration hydrogen peroxide is 34.5 wt % and the stability is 98.1%.

[0129] 4) Refining The crude hydrogen peroxide is cooled and then subjected to agglomeration separation and gas stripping to obtain the finished hydrogen peroxide product.

[0130] The hydrogen peroxide content in the finished hydrogen peroxide solution is 45.6wt%.

[0131] Specifically, the temperature of the coalescence separation was 35°C.

[0132] Specifically, the residence time for the coalescence separation was 6 min.

[0133] Specifically, the temperature of the gas stripping was 35°C.

[0134] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0135] 5) Detection It was detected that the total organic carbon content in the crude hydrogen peroxide was 0.021wt%, which further decreased to 0.019wt% after agglomeration and separation, and the total organic carbon content in the finished hydrogen peroxide obtained after gas stripping was 0.017wt%.

[0136] It can be seen from this that if the first oxidizing liquid is not fully mixed with the low-concentration hydrogen peroxide, the concentration of the produced hydrogen peroxide product will be affected, and a hydrogen peroxide product with a concentration close to 50wt% cannot be produced.

[0137] Comparative Example 4 The difference between this comparative example and Example 1 is that in this comparative example, in step 2), only a static separation tank is used for separation, and the specific steps are: 1) Hydrogenation The working liquid is hydrogenated to obtain a hydrogenated liquid, which is oxidized and filtered to obtain a first oxidized liquid, wherein the content of hydrogen peroxide in the first oxidized liquid is 15.2 g / L.

[0138] Specifically, the working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate as a mixed solvent, wherein the anthraquinone concentration is 220 kg / m 3 .

[0139] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate is 68:18:12:2.

[0140] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 15.6 g / L.

[0141] 2) Two-phase separation After the first oxidation liquid is fully mixed with the low-concentration hydrogen peroxide, it is separated only by using a static separation tank without further separation by a coalescing separator. The oil phase separated from the upper part of the static separation tank is the second oxidation liquid, and the water phase obtained from the bottom of the static separation tank is a crude hydrogen peroxide product with an increased concentration.

[0142] Specifically, the hydrogen peroxide content in the second oxidation liquid is 8.8 g / L.

[0143] Specifically, the concentration of the crude hydrogen peroxide is 50.3 wt % and the stability is 97.5%.

[0144] 3) Extraction The second oxidizing liquid was countercurrently extracted with 0.15 g / L phosphoric acid aqueous solution to obtain low-concentration hydrogen peroxide, which was mixed with the first oxidizing liquid in step 2), and the residue was detected to be 0.16 g / L.

[0145] Specifically, the volume ratio of the second oxidizing liquid to the weakly acidic water is 68:1.

[0146] Specifically, the concentration of the low-concentration hydrogen peroxide is 37.3 wt % and the stability is 97.9%.

[0147] 4) Refining The high-concentration hydrogen peroxide crude product is cooled and then subjected to agglomeration separation and gas stripping to obtain a high-concentration hydrogen peroxide finished product.

[0148] The hydrogen peroxide content in the high-concentration hydrogen peroxide product is 50.3wt%.

[0149] Specifically, the temperature of the coalescence separation was 35°C.

[0150] Specifically, the residence time for the coalescence separation was 6 min.

[0151] Specifically, the temperature of the gas stripping was 35°C.

[0152] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0153] 5) Detection It was detected that the total organic carbon content in the crude hydrogen peroxide was 0.035wt%, which decreased to 0.031wt% after agglomeration and separation, and the total organic carbon content in the finished hydrogen peroxide obtained after gas stripping was 0.027wt%.

[0154] It can be seen from this that if the first oxidizing liquid and the low-concentration hydrogen peroxide are not fully separated, the total organic carbon content in the high-concentration hydrogen peroxide crude product will increase, resulting in the total organic carbon content in the high-concentration hydrogen peroxide finished product exceeding the standard.

[0155] Comparative Example 5 The difference between this comparative example and Example 1 is that in this comparative example, the first oxidizing liquid is not mixed with low-concentration hydrogen peroxide and subjected to two-phase separation, that is, the first oxidizing liquid is directly fed into the extraction process without undergoing the process of mixing and separating with low-concentration hydrogen peroxide after oxidation. Under the premise of ensuring safe production (i.e., the raffinate does not exceed 0.25 g / L), the extraction section is simulated and calculated, and the highest concentration of hydrogen peroxide that can be obtained is 41.6 wt%.

[0156] Example 2 1) Hydrogenation The working liquid is hydrogenated to obtain a hydrogenated liquid, which is oxidized and filtered to obtain a first oxidized liquid, wherein the content of hydrogen peroxide in the first oxidized liquid is 17.1 g / L.

[0157] Specifically, the working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and methyl cyclohexyl acetate as a mixed solvent, wherein the anthraquinone concentration is 235 kg / m 3 .

[0158] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and methyl cyclohexyl acetate is 65:20:13:2.

[0159] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 17.5 g / L.

[0160] 2) Two-phase separation The first oxidation liquid is fully mixed with low-concentration hydrogen peroxide and then separated into an aqueous phase and an oil phase. The oil phase obtained by separation is the second oxidation liquid, and the aqueous phase obtained is a crude product of high-concentration hydrogen peroxide.

[0161] Specifically, the hydrogen peroxide content in the second oxidation liquid is 10.2 g / L.

[0162] Specifically, the concentration of the crude high-concentration hydrogen peroxide is 53.3 wt % and the stability is 97.2%.

[0163] 3) Countercurrent extraction The second oxidizing liquid is countercurrently extracted with a 0.15 g / L phosphoric acid aqueous solution to obtain a low-concentration hydrogen peroxide solution, and the low-concentration hydrogen peroxide solution is mixed with the first oxidizing liquid in step 2), and the residual is detected to be 0.15 g / L.

[0164] Specifically, the volume ratio of the second oxidizing liquid to the weakly acidic water is 68:1.

[0165] Specifically, the concentration of the low-concentration hydrogen peroxide solution is 40.8 wt % and the stability is 97.6%.

[0166] 4) Refining The high-concentration hydrogen peroxide crude product is cooled and then subjected to agglomeration separation and gas stripping to obtain a high-concentration hydrogen peroxide finished product.

[0167] The hydrogen peroxide content in the high-concentration hydrogen peroxide product is 53.3wt%.

[0168] Specifically, the temperature of the coalescence separation was 35°C.

[0169] Specifically, the residence time for the coalescence separation was 6 min.

[0170] Specifically, the temperature of the gas stripping was 35°C.

[0171] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0172] 5) Detection It was detected that the total organic carbon content in the crude high-concentration hydrogen peroxide was 0.022wt%, which decreased to 0.020wt% after agglomeration and separation, and the total organic carbon content in the finished hydrogen peroxide product obtained after gas stripping was 0.019wt%.

[0173] Comparative Example 6 The difference between this comparative example and Example 2 is that in this comparative example, the first oxidizing liquid is not mixed with low-concentration hydrogen peroxide and subjected to two-phase separation, that is, the first oxidizing liquid is directly fed into the extraction process without undergoing the process of mixing and separating with low-concentration hydrogen peroxide after oxidation. Under the premise of ensuring safe production (i.e., the raffinate does not exceed 0.25 g / L), the extraction section is simulated and calculated, and the highest concentration of hydrogen peroxide that can be obtained is 43.5 wt%.

[0174] Table 3 Effect of two-phase separation on the concentration of high-concentration hydrogen peroxide finished product From the data in Table 3, it can be concluded that the oxidizing liquid is not mixed and separated with the low-concentration oxidizing liquid, but is directly sent to the extraction process for extraction. Under the premise of ensuring that the residue does not exceed the standard, the maximum concentration of the crude hydrogen peroxide that can be produced can only reach 43.5wt%, which is far below 50wt% and cannot meet the product concentration requirements.

[0175] The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art.

[0176] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing high-concentration hydrogen peroxide, characterized in that: The following steps are involved: a) subjecting the working solution to a hydrogenation reaction to obtain a hydrogenated liquid, oxidizing and filtering to obtain a first oxidized liquid, wherein the hydrogen peroxide content of the first oxidized liquid is 12.5-20.0 g / L; b) After the low-concentration hydrogen peroxide is fully mixed with the first oxidation liquid, the water phase and the oil phase are separated, the oil phase obtained by separation is the second oxidation liquid, and the water phase obtained is the high-concentration hydrogen peroxide crude product, and the concentration of the low-concentration hydrogen peroxide mixed with the first oxidation liquid is 34-42wt%; c) countercurrent extraction of weakly acidic water and the second oxidation liquid to obtain low-concentration hydrogen peroxide, and the low-concentration hydrogen peroxide is mixed with the first oxidation liquid in step b); d) Cooling the crude high-concentration hydrogen peroxide product, performing agglomeration separation and gas stripping to obtain a high-concentration hydrogen peroxide product with a concentration of 48-56wt%.

2. A method for preparing high-concentration hydrogen peroxide according to claim 1, characterized in that: In step b), the hydrogen peroxide content in the second oxidation liquid is 6.5-12.0 g / L.

3. A method for preparing high-concentration hydrogen peroxide according to claim 1, characterized in that: In step a), the working liquid is obtained by dissolving amyl anthraquinone or ethyl anthraquinone and amyl anthraquinone in a solvent, the solvent is a mixed solvent consisting of a non-polar solvent heavy aromatic hydrocarbon and a polar solvent, the anthraquinone concentration in the working liquid is 150-360 kg / m3, the polar solvent is tetrabutyl urea, diisobutyl carbinol and / or trioctyl phosphate, methyl cyclohexyl acetate, and the volume ratio of the polar solvent to the non-polar solvent is 15:85-40:

60.

4. A method for preparing high-concentration hydrogen peroxide according to claim 1 or 2, characterized in that: The hydrogenation efficiency of the hydrogenation reaction is 13.0~20.5g / L.

5. A method for preparing high-concentration hydrogen peroxide according to claim 1, characterized in that: In step a), during filtration, the filter element accuracy is 0.5~5μm, and the retention efficiency is ≥99.8%.

6. A method for preparing high-concentration hydrogen peroxide according to claim 1, characterized in that: In step b), the mixing and separation temperatures are both 48-53°C.

7. A method for preparing high-concentration hydrogen peroxide according to claim 1, characterized in that: In step c), The volume ratio of the second oxidizing liquid to the weakly acidic water is 45:1 to 85:1, and the volume ratio of the weakly acidic water to the second oxidizing liquid is 1:85 to 1:45; Weakly acidic water is a 0.1~0.4g / L phosphoric acid aqueous solution; The extraction temperature is 48~53℃.

8. A method for preparing high-concentration hydrogen peroxide according to claim 1, characterized in that: In step d), the cooling temperature is 25-40°C.

9. A method for preparing high-concentration hydrogen peroxide according to claim 1 or 8, characterized in that: In step d), when the crude product of high concentration hydrogen peroxide is agglomerated and separated: The operating temperature is 25~40℃; The residence time for coalescence separation is 2~15min.

10. A method for preparing high-concentration hydrogen peroxide according to claim 9, characterized in that: In step d), during gas stripping: The operating temperature is 25~40℃; The volume ratio of air to liquid is 1:65~1:20; The operating pressure is 0.5~1.0MPaG.

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