Method for producing high-concentration hydrogen peroxide through extraction

Abstract

The invention relates to the technical field of hydrogen peroxide production, and discloses a method for producing high-concentration hydrogen peroxide through extraction, which comprises the following steps: firstly, carrying out primary extraction on low-concentration hydrogen peroxide and a first oxidation solution with higher hydrogen peroxide content to obtain a high-concentration hydrogen peroxide crude product; the second oxidation liquid obtained through the first extraction is subjected to countercurrent extraction with weakly acidic water to obtain low-concentration hydrogen peroxide, and meanwhile, residual hydrogen peroxide in the second oxidation liquid is completely extracted, so that the concentration of the low-concentration hydrogen peroxide is ensured, and meanwhile, the content of hydrogen peroxide in raffinate obtained through the second extraction does not exceed the standard; the hydrogen peroxide product with the concentration close to 50wt% can be produced without concentration, and compared with a process for producing high-concentration hydrogen peroxide through concentration, the process is mild in operation condition and relatively simple in flow, production energy consumption is reduced, and the process is higher in safety and reliability.

Description

Technical Field

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

[0002] As a bulk green chemical, hydrogen peroxide is widely used in many fields such as chemical manufacturing, papermaking, textiles, and environmental protection. The method for large-scale industrial production of hydrogen peroxide is the anthraquinone method, which uses alkyl anthraquinone dissolved in an organic solvent as a carrier for hydrogenation and oxidation. Hydrogen peroxide is obtained 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 oxidizing liquid can be extracted with water to obtain hydrogen peroxide. The working liquid after extraction, i.e., the raffinate, is returned to the hydrogenation process for recycling after appropriate treatment.

[0003] Since hydrogen peroxide can be miscible with water in any proportion, hydrogen peroxide has a variety of concentration specifications. Commonly used in industry are 27.5wt%, 35wt% and 50wt%. At present, the most used is hydrogen peroxide with a concentration of about 35wt%. Hydrogen peroxide with a concentration of 50wt% is relatively less used, but high-concentration hydrogen peroxide must be used when producing propylene oxide and epichlorohydrin. When cyclohexanone ammoximation produces cyclohexanone oxime, the use of high-concentration hydrogen peroxide can not only improve the reaction efficiency, but also reduce wastewater discharge.

[0004] However, unlike the direct extraction to produce 27.5-35wt% hydrogen peroxide, higher concentration hydrogen peroxide needs to be produced by concentration, that is, 27.5-35wt% hydrogen peroxide is evaporated to remove part of the water for concentration to obtain a hydrogen peroxide product with a concentration of about 50wt%. This is because during extraction, it is necessary to ensure that the hydrogen peroxide content in the raffinate, i.e., the raffinate, does not exceed 0.30g / L to prevent the entrained hydrogen peroxide in the working liquid returned to the hydrogenation reactor from being decomposed by the hydrogenation catalyst, and the generated oxygen and hydrogen are mixed to cause safety accidents. During extraction, while ensuring that the raffinate does not exceed the standard, it is also necessary to strive to ensure that the concentration of hydrogen peroxide produced by extraction meets the standard. In actual production, it is prioritized to ensure that the raffinate does not exceed the standard. Affected by the distribution coefficient of hydrogen peroxide in the aqueous phase and the working liquid and the design of the extraction tower, the higher the concentration of hydrogen peroxide produced by extraction, the higher the raffinate. Therefore, in order to ensure that the raffinate does not exceed the standard, the concentration of hydrogen peroxide directly produced by extraction is limited. Under normal circumstances, extraction can directly produce a product with a concentration of about 35%. If the concentration of hydrogen peroxide produced by extraction exceeds 40wt%, it is easy to cause the residue to exceed the standard. Therefore, the concentration of hydrogen peroxide produced by conventional technology is difficult to exceed 40wt%, such as patent CN205973792U. If a higher concentration of hydrogen peroxide is required, it needs to be produced through a concentration process.

[0005] Since the rare hydrogen peroxide (concentration is generally less than 40wt%) evaporates water when it is concentrated, although the falling film evaporation technology is used, a certain temperature and vacuum degree are still required to quickly remove water and concentrate. Not only is the energy consumption high, but the hydrogen peroxide will accelerate decomposition after being heated during the concentration process, so concentration is a relatively dangerous process. Therefore, if high-concentration hydrogen peroxide can be produced without the concentration process, it is of great significance to reduce production costs and improve process safety. Summary of the invention

[0006] In order to solve the technical problems raised in the above background technology that high-concentration hydrogen peroxide cannot be produced by an extraction process under the premise of ensuring that the raffinate does not exceed the standard, and when a concentration method is used to prepare high-concentration hydrogen peroxide, the energy consumption required is too high, the safety risk is large, and the organic carbon content in the obtained high-concentration hydrogen peroxide is too high, the present invention provides a method for producing high-concentration hydrogen peroxide by extraction, so as to achieve the preparation of high-concentration hydrogen peroxide without a concentration process, reduce production costs, improve production safety, and obtain high-concentration hydrogen peroxide with a total organic carbon content of less than 0.03wt%.

[0007] The specific technical scheme of the present invention is: a method for producing high-concentration hydrogen peroxide by extraction, comprising the following steps: 1) hydrogenating, oxidizing and filtering a working liquid to obtain a first oxidation liquid, wherein the hydrogen peroxide content in the first oxidation liquid is 12.5 to 20.0 g / L; 2) countercurrent extraction of the first oxidation liquid and low-concentration hydrogen peroxide, wherein the aqueous phase is a crude high-concentration hydrogen peroxide product, the oil phase is a second oxidation liquid, the concentration of the low-concentration hydrogen peroxide is 36-42 wt%, and the content of hydrogen peroxide in the second oxidation liquid is 7.5-13.0 g / L; 3) countercurrent extraction of the second oxidation liquid and weakly acidic water to obtain a low-concentration hydrogen peroxide solution with a concentration of 36 to 42 wt%, and countercurrent extraction of the low-concentration hydrogen peroxide solution with the first oxidation liquid in step 2); 4) After cooling the crude high-concentration hydrogen peroxide, the crude product is purified, agglomerated and separated, and gas stripped in sequence to obtain a high-concentration hydrogen peroxide product.

[0008] The present invention proposes a method for producing high-concentration hydrogen peroxide with a concentration of about 50wt%: a double extraction process is adopted, wherein the extraction in step 2) is mainly for producing high-concentration hydrogen peroxide, and the extraction in step 3) is mainly for producing low-concentration hydrogen peroxide, and the hydrogen peroxide in the oxidation liquid is extracted cleanly to ensure that the residual of the working liquid returned to the hydrogenation process does not exceed the standard. The first oxidation liquid is subjected to countercurrent extraction with the low-concentration hydrogen peroxide, and the aqueous phase obtains a high-concentration hydrogen peroxide crude product, and the oil phase obtains the second oxidation liquid. By extracting the oxidation liquid with a high hydrogen peroxide content with the low-concentration hydrogen peroxide, part of the hydrogen peroxide in the oxidation liquid is extracted into the low-concentration hydrogen peroxide, thereby increasing the concentration of the low-concentration hydrogen peroxide, obtaining a high-concentration hydrogen peroxide crude product, and then cooling and separating to remove the entrained organic matter, that is, obtaining a high-concentration hydrogen peroxide finished product. In order to improve the safety of the low-concentration hydrogen peroxide after the concentration is increased and extracted with the working liquid, a relatively low extraction operation temperature and nitrogen atmosphere protection measures are adopted during the first extraction. After the first extraction, the first oxidation liquid obtains the second oxidation liquid, which contains a certain concentration of hydrogen peroxide and cannot be directly returned to the hydrogenation process. Therefore, it is sent to the second extraction, and the second oxidation liquid is countercurrently extracted with weakly acidic water to obtain low-concentration hydrogen peroxide from the bottom, which is then sent to step 2); the working liquid obtained from the upper part after the second extraction, that is, the raffinate, needs to be controlled to be no higher than 0.25g / L, which is lower than the upper limit control index of 0.30g / L in the existing process to ensure safe production. The raffinate obtained after the second extraction is subjected to conventional water removal treatment and then returned to the hydrogenation process for hydrogenation reaction, thereby realizing the recycling of the working liquid.

[0009] The concentration of low-concentration hydrogen peroxide cannot be too low, otherwise hydrogen peroxide with a concentration close to 50wt% cannot be obtained, so there are high requirements for the process conditions of the first extraction and the second extraction and the design of the extraction tower equipment. Because it is necessary to extract the hydrogen peroxide in the first oxidation liquid into the low-concentration hydrogen peroxide, and it is also required that the residual of the raffinate after the second extraction does not exceed the standard, the hydrogen peroxide content in the first oxidation liquid is required to be high. At the same time, it is also required that the distribution coefficient of hydrogen peroxide between water and working liquid is high, so that the hydrogen peroxide in the first oxidation liquid can enter the rare hydrogen peroxide as much as possible, and the concentration of hydrogen peroxide obtained is also higher, and the residual in the raffinate obtained after the second extraction is also easier to meet the standard. Although reducing the amount of polar solvent can increase the distribution coefficient, because the hydrogenation efficiency of the hydrogenation liquid is required to be high, the content of polar solvent cannot be too low, otherwise it is not enough to dissolve anthraquinone and hydroanthraquinone.

[0010] Furthermore, in step 1), the concentration of anthraquinone in the working solution is 150 to 360 kg / m 3The solvent is a mixed solvent composed of heavy aromatic hydrocarbons and polar solvents, the volume ratio of heavy aromatic hydrocarbons to polar solvents is 50:50 to 80:20, and the polar solvent is a composite solvent composed of tetrabutyl urea, diisobutyl carbinol and / or trioctyl phosphate and methyl cyclohexyl acetate. The use of multiple solvents can improve the solubility of anthraquinone and hydroanthraquinone, providing a prerequisite for obtaining an oxidizing solution with a high hydrogen peroxide content.

[0011] Preferably, the working solution is obtained by dissolving ethyl anthraquinone and amyl anthraquinone or amyl anthraquinone in a solvent.

[0012] Furthermore, in step 1), the hydrogenation efficiency of hydrogenation is 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 stability of low-concentration hydrogen peroxide is ≥97.5% to avoid the safety risk of uncontrolled decomposition of hydrogen peroxide due to the low stability of high-concentration hydrogen peroxide.

[0015] Preferably, the stability of the high concentration hydrogen peroxide is ≥97.0%.

[0016] Preferably, in step 2), the countercurrent extraction selects the extraction tower (hereinafter referred to as the first extraction tower), the first extraction tower has a height-to-diameter ratio of 2.5:1 to 5:1, and the number of tower plates is 5 to 24; a high-concentration hydrogen peroxide separation standing section is provided at the lower part of the first extraction tower, and the height of the standing section is 1.5 to 4.5 meters; a wire mesh composited with stainless steel and PP or stainless steel and PTFE is provided under each tower plate to enhance the extraction effect; stainless steel structured packing, stainless steel and PP or stainless steel and PTFE composite packing are provided at the high-concentration hydrogen peroxide standing section and the upper part of the first extraction tower to enhance the separation effect.

[0017] Furthermore, in step 2), the volume ratio of the first oxidizing liquid to the low-concentration hydrogen peroxide solution is 45:1 to 80:1.

[0018] Furthermore, in step 2), the operating temperature of the countercurrent extraction is 38-46°C.

[0019] Furthermore, a pipeline and a valve for continuously replenishing nitrogen are arranged at the upper part of the first extraction tower to keep the extraction operation always under a nitrogen atmosphere with an operating pressure of 0.3 to 40 kPa.

[0020] Furthermore, in step 3), the temperature of the countercurrent extraction is 48-55°C.

[0021] Furthermore, in step 2), the content of hydrogen peroxide in the second oxidation solution is 7.5-13.0 g / L.

[0022] Furthermore, in step 3), the weakly acidic water is a 0.1-0.4 g / L phosphoric acid aqueous solution, and the weakly acidic water is prepared by adding phosphoric acid to secondary desalted water. The presence of phosphoric acid reduces the decomposition of hydrogen peroxide.

[0023] Furthermore, in step 3), the volume ratio of the first oxidizing liquid to the weakly acidic water is 45:1 to 85:1; and the content of hydrogen peroxide in the raffinate exiting the second extraction tower is ≤0.25 g / L.

[0024] Preferably, in step 3), the countercurrent extraction selects an extraction tower (hereinafter referred to as the second extraction tower), the height-to-diameter ratio of the second extraction tower is 5:1-10:1, the number of tower plates is 26-58, and a wire mesh packing composited with stainless steel and PP or stainless steel and PTFE is arranged under each tower plate to enhance the extraction effect, ensure that the residue does not exceed the standard and the concentration of the rare hydrogen peroxide meets the requirements. In order to reduce the working liquid entrained by the rare hydrogen peroxide entering the first extraction tower, a rare hydrogen peroxide separation static section is arranged at the bottom of the second extraction tower, the height of the static section is 1.5-4.5 meters, and stainless steel structured packing, stainless steel and PP or stainless steel and PTFE composite packing are arranged at the top of the static section and the second extraction tower to enhance the separation effect.

[0025] Furthermore, in step 4), the crude high concentration hydrogen peroxide is cooled to 15-35°C.

[0026] Furthermore, in step 4), the volume ratio of heavy aromatics to high concentration crude hydrogen peroxide is 45:1 to 70:1.

[0027] Furthermore, in step 4), the total organic carbon content in the high-concentration hydrogen peroxide product is ≤0.025wt%.

[0028] In order to improve the safety of purification operations and prevent safety problems caused by the mixing of high-concentration hydrogen peroxide and heavy aromatic hydrocarbons at higher operating temperatures, the density of high-concentration hydrogen peroxide is significantly higher than that of low-concentration hydrogen peroxide, making it easier to separate high-concentration hydrogen peroxide and heavy aromatic hydrocarbons, so purification can be carried out at a relatively low temperature.

[0029] Preferably, in step 4), purification is carried out in a sieve plate tower, the operating temperature is 15-35° C., the height-to-diameter ratio of the purification tower is 6:1-9:1, and the number of tower plates is 20-35; a high-concentration hydrogen peroxide crude product separation standing section is provided at the lower part of the purification tower, and the height of the standing section is 1-3 meters.

[0030] Furthermore, pipelines and valves for continuously replenishing nitrogen are arranged on the upper part of the purification tower to keep the purification operation always under a nitrogen atmosphere with an operating pressure of 0.3 to 40 kPa.

[0031] Preferably, the used heavy aromatic solvent is sent to the working liquid preparation place after purification, and is added into the working liquid system as an effective component of the working liquid after being washed with water, so as to avoid the waste of heavy aromatics.

[0032] Preferably, when downstream users do not have high requirements for the total organic carbon content in the finished hydrogen peroxide product, the purification step may not be required, thereby avoiding direct contact between high-concentration hydrogen peroxide and heavy aromatic solvents, and improving process safety.

[0033] Preferably, the coalescence separation is carried out in a coalescence separator, and the coalescence filter element of the coalescence separator is made of one or more of ethylene-tetrafluoroethylene copolymer, fluorinated ethylene propylene copolymer, soluble polytetrafluoroethylene, polyvinylidene fluoride or polyphenylene sulfide.

[0034] Preferably, in step 4), the gas stripping is carried out in a packed tower, and the height-to-diameter ratio of the gas stripping tower is 3.5:1 to 8:1; the air used is introduced from the air used when entering the oxidation reactor, and the air used for gas stripping is returned to the oxidation reactor for continued use, so the gas stripping will not cause the loss of organic materials in the system, and no waste gas will be generated; the packing in the gas stripping tower is one or more of stainless steel structured packing or ball rings, step rings, conjugate rings, and saddle ring random packing.

[0035] Furthermore, the operating temperature of the gas stripping is 15-35° C., and the operating pressure is 0.5-1.0 MPaG.

[0036] Furthermore, the volume ratio of hydrogen peroxide to air (standard formula) entering the stripping tower is 1:20 to 1:65. If the air intake is too low, it will not reduce the total organic carbon content in hydrogen peroxide; if the air intake is too large, the residence time of hydrogen peroxide is too short or even atomized, and the expected effect will not be achieved.

[0037] Compared with the prior art, the beneficial effects of the present invention are: 1) The present invention adopts a double extraction process, wherein a low-concentration hydrogen peroxide is first extracted with a first oxidation liquid having a high hydrogen peroxide content to obtain a high-concentration hydrogen peroxide crude product; the second oxidation liquid obtained by the first extraction is then subjected to countercurrent extraction with weakly acidic water to obtain a low-concentration hydrogen peroxide, and the remaining hydrogen peroxide in the second oxidation liquid is extracted cleanly, while ensuring the concentration of the rare hydrogen peroxide, the hydrogen peroxide content in the raffinate of the second extraction is also ensured not to exceed the standard, and the production of a hydrogen peroxide product with a concentration of nearly 50wt% is achieved without concentration. The process of the present invention has mild operating conditions, a relatively simple process, reduced production energy consumption, and higher process safety and reliability.

[0038] 2) The present invention adopts an efficient working liquid system. The hydrogenation efficiency of the working liquid after hydrogenation 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 hydrogen efficiency of 7 to 9 g / L of the fixed bed or 11 to 12 g / L of the conventional fluidized bed, at the same hydrogen peroxide production scale, the technical working liquid circulation volume of the present invention is lower and the production efficiency is higher.

[0039] 3) The present invention adopts a method combining purification, agglomeration separation and gas stripping, which can effectively reduce the total organic carbon content in the crude hydrogen peroxide product. The total organic carbon content of the obtained hydrogen peroxide product with a concentration of about 50wt% is significantly lower than the excellent product index of the national standard GB / T1616-2014 "Industrial Hydrogen Peroxide". BRIEF DESCRIPTION OF THE DRAWINGS

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

[0041] The accompanying drawings are marked as follows: 1. oxidizing liquid storage tank; 2. oxidizing liquid pump; 3. oxidizing liquid filter; 4. first extraction tower; 5. second extraction tower; 6. low-concentration hydrogen peroxide temporary storage tank; 7. rare product pump; 8. cooler; 9. high-concentration hydrogen peroxide crude product temporary storage tank; 10. crude product pump; 11. purification tower; 12. coalescer; 13. gas stripping tower; 14. first extraction tower plate; 15. first extraction tower stationary end packing; 16 first extraction tower packing; 17. second extraction tower plate; 18. second extraction tower packing; 19. water removal system; 20. heavy aromatic solvent; 21. air; 22. high-concentration hydrogen peroxide finished product. DETAILED DESCRIPTION

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

[0043] Overall embodiment like Figure 1As shown, a method for producing high-concentration hydrogen peroxide by extraction, the working liquid undergoes a hydrogenation reaction in a hydrogenation reactor to obtain a hydrogenated liquid, which is filtered and enters an oxidation reactor, and the obtained first oxidized liquid enters an oxidized liquid storage tank 1, and an oxidized liquid pump 2 sends the first oxidized liquid in the oxidized liquid storage tank 1 to the bottom of a first extraction tower 4 through an oxidized liquid filter 3, and performs countercurrent extraction with low-concentration hydrogen peroxide sent by a rare product pump 7 in the first extraction tower, and a high-concentration crude hydrogen peroxide product is obtained at the top of the tower, and a second oxidized liquid is obtained at the top of the first extraction tower, and the second oxidized liquid is sent to the bottom of a second extraction tower 5, and performs countercurrent extraction with weakly acidic water added from the top of the second extraction tower 5, and a low-concentration hydrogen peroxide is obtained at the bottom of the tower, and a raffinate is obtained at the top of the second extraction tower, and enters a water removal system 19. After dehydration, the raffinate re-enters the hydrogenation reactor for hydrogenation reaction to realize the recycling of the working liquid. After the crude high-concentration hydrogen peroxide is cooled to 25° C. by the cooler 8, it enters the crude high-concentration hydrogen peroxide temporary storage tank 9, and is sent to the top of the purification tower 11 through the crude product pump 10, and is countercurrently contacted with the heavy aromatic hydrocarbons 20 entering from the bottom of the tower. Part of the organic matter entrained in the crude high-concentration hydrogen peroxide is dissolved in the heavy aromatic hydrocarbons. The heavy aromatic hydrocarbons after purification are sent back to the working liquid configuration, and are replenished into the working liquid system after washing. The purified high-concentration hydrogen peroxide enters the coalescer 12, and the hydrogen peroxide after coalescence and separation enters the stripping tower 13, and is stripped by using part of the air 21 entering the oxidation reactor to obtain the final high-concentration hydrogen peroxide product 22.

[0044] Specifically, the filter element in the oxidizing liquid filter 3 has a filter element precision of 1 μm and a retention efficiency of 99.9%.

[0045] Specifically, the height-to-diameter ratio of the first extraction tower is 3.5:1, the number of tower plates is 18, and a wire mesh filler composite of stainless steel and PTFE is arranged under each tower plate. A high-concentration hydrogen peroxide crude product separation static section is arranged at the lower part of the first extraction tower, with a height of 3.0 meters.

[0046] Specifically, the height-to-diameter ratio of the second extraction tower is 6.5:1, the number of tower plates is 36, a wire mesh filler composite of stainless steel and PTFE is arranged under each tower plate, and a low-concentration hydrogen peroxide separation static section is arranged at the lower part of the second extraction tower with a height of 2.0 meters.

[0047] Specifically, the height-to-diameter ratio of the purification tower is 7:1, the number of tower plates is 24, and a high-concentration hydrogen peroxide separation static section is set at the lower part of the purification tower with a height of 1.5 meters.

[0048] Specifically, the coalescing filter element of the coalescing separator is made of ethylene-tetrafluoroethylene copolymer.

[0049] Specifically, the operating pressure of the stripping tower is 0.6 MPaG.

[0050] Specific examples and comparative examples.

[0051] 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 14.9 g / L.

[0052] The working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate as a mixed solvent, among which the anthraquinone concentration is 215kg / m 3 .

[0053] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate is 63:20:15:2.

[0054] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 15.1 g / L.

[0055] 2) First extraction The first oxidation liquid is subjected to countercurrent extraction with low-concentration hydrogen peroxide to obtain a high-concentration hydrogen peroxide crude product from the lower part of the first extraction tower, and the second oxidation liquid is obtained from the upper part.

[0056] Specifically, the volume ratio of the first oxidizing liquid to the low-concentration hydrogen peroxide solution is 68:1.

[0057] Specifically, the concentration of the crude high-concentration hydrogen peroxide is 50.1 wt %.

[0058] Specifically, the content of hydrogen peroxide in the second oxidizing liquid is 9.4 g / L.

[0059] Specifically, the operating temperature of the first extraction was 42°C.

[0060] Specifically, during the first extraction, the nitrogen pressure was maintained at 5 kPa.

[0061] 3) Second extraction The second oxidizing liquid is subjected to countercurrent extraction with a 0.15 g / L aqueous phosphoric acid solution to obtain low-concentration hydrogen peroxide from the lower part of the second extraction tower. The obtained low-concentration hydrogen peroxide is mixed with the first oxidizing liquid in step 2). After testing, the hydrogen peroxide content in the raffinate is 0.20 g / L.

[0062] Specifically, the concentration of the low-concentration hydrogen peroxide solution is 39.1 wt % and the stability is 97.9%.

[0063] Specifically, the volume ratio of the second oxidizing liquid to the 0.15 g / L phosphoric acid aqueous solution is 68:1.

[0064] Specifically, the operating temperature of the second extraction is 50°C.

[0065] 4) Refining The crude high-concentration hydrogen peroxide is cooled to 25°C and then purified, coalesced and separated, and stripped in sequence to obtain a high-concentration hydrogen peroxide product. The purification is performed by countercurrent contact of a heavy aromatic solvent with the high-concentration hydrogen peroxide.

[0066] Specifically, the crude high-concentration hydrogen peroxide solution is cooled to 25°C.

[0067] Specifically, during purification, the volume ratio of heavy aromatics to high-concentration hydrogen peroxide crude product was 60:1, and the nitrogen pressure was maintained at 5 kPa.

[0068] Specifically, the residence time for the coalescence separation was 6 min.

[0069] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0070] Specifically, the hydrogen peroxide content in the high-concentration double water finished product is 50.1wt% and the stability is 97.5%.

[0071] 5) Detection The total organic carbon content in the crude high-concentration hydrogen peroxide was 0.033wt%, which decreased to 0.028wt% after purification, and further decreased to 0.026wt% after agglomeration and separation. The total organic carbon content in the high-concentration hydrogen peroxide product obtained after gas stripping was 0.021wt%. It can be seen that with the progress of purification, agglomeration and separation, and gas stripping, the total organic carbon content in the hydrogen peroxide product decreases in sequence.

[0072] Comparative Example 1 The difference between this comparative example and Example 1 is that in this comparative example, the concentration of the low-concentration hydrogen peroxide is reduced to 35.3wt% (that is, when the concentration of the low-concentration hydrogen peroxide is low, it is tested whether the concentration of the hydrogen peroxide product finally produced can be close to 50wt%), and the rest of the process is the same as Example 1, 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 14.9 g / L.

[0073] The working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate as a mixed solvent, among which the anthraquinone concentration is 215kg / m 3 .

[0074] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate is 63:20:15:2.

[0075] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 15.1 g / L.

[0076] 2) First extraction The first oxidation liquid is subjected to countercurrent extraction with low-concentration hydrogen peroxide to obtain a crude hydrogen peroxide product with increased concentration from the lower part of the extraction tower, and a second oxidation liquid is obtained from the upper part.

[0077] Specifically, the volume ratio of the first oxidizing liquid to the low-concentration hydrogen peroxide solution is 55:1.

[0078] Specifically, the concentration of the crude hydrogen peroxide with increased concentration was 44.8 wt %.

[0079] Specifically, the content of hydrogen peroxide in the second oxidizing liquid is 9.2 g / L.

[0080] Specifically, the operating temperature of the first extraction was 42°C.

[0081] Specifically, during the first extraction, the nitrogen pressure was maintained at 5 kPa.

[0082] 3) Second extraction The second oxidizing liquid is subjected to countercurrent extraction with a 0.15 g / L aqueous phosphoric acid solution to obtain low-concentration hydrogen peroxide from the lower part of the second extraction tower. The obtained low-concentration hydrogen peroxide is mixed with the first oxidizing liquid in step 2). After testing, the hydrogen peroxide content in the raffinate is 0.20 g / L.

[0083] Specifically, the concentration of the low-concentration hydrogen peroxide is 33.7 wt % and the stability is 98.2%.

[0084] Specifically, the volume ratio of the second oxidizing liquid to the 0.15 g / L phosphoric acid aqueous solution is 55:1.

[0085] Specifically, the operating temperature of the second extraction is 50°C.

[0086] 4) Refining The crude hydrogen peroxide is cooled to 25°C and then purified, coalesced and separated, and stripped in sequence to obtain a finished hydrogen peroxide product with increased concentration. A heavy aromatic solvent is selected for purification and is in countercurrent contact with the crude hydrogen peroxide product with increased concentration.

[0087] Specifically, the crude hydrogen peroxide was cooled to 25°C.

[0088] Specifically, during purification, the volume ratio of heavy aromatics to crude hydrogen peroxide was 60:1, and the nitrogen pressure was maintained at 5 kPa.

[0089] Specifically, the residence time for the coalescence separation was 6 min.

[0090] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0091] Specifically, the hydrogen peroxide content in the finished hydrogen peroxide product is 44.8wt% and the stability is 97.4%.

[0092] 5) Detection It was detected that the total organic carbon content in the crude hydrogen peroxide was 0.032wt%, which decreased to 0.028wt% after purification, and further decreased to 0.024wt% after agglomeration and separation. The total organic carbon content in the finished hydrogen peroxide obtained after gas stripping was 0.020wt%.

[0093] Table 1 Effect of low concentration hydrogen peroxide concentration on the concentration of finished hydrogen peroxide It can be seen from the data in Table 1 that by increasing the extraction water intake to reduce the concentration of the low-concentration hydrogen peroxide produced by the extraction, the hydrogen peroxide content in the subsequent second oxidation liquid and the concentration of the hydrogen peroxide product will both decrease. When the concentration of the low-concentration hydrogen peroxide is low, a hydrogen peroxide product with a concentration close to 50wt% cannot be produced.

[0094] Comparative Example 2 The difference between this comparative example and Example 1 is that in this comparative example, the content of hydrogen peroxide in the first oxidation liquid in step 2) is reduced to 11.4 g / L (that is, the content of hydrogen peroxide in the first oxidation liquid is reduced by reducing the hydrogenation efficiency, and when the content of hydrogen peroxide in the first oxidation liquid is too low, whether the concentration of the hydrogen peroxide product can meet the standard is detected), and the rest of the process is the same as in Example 1, 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 11.4 / L.

[0095] The working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate as a mixed solvent, among which the anthraquinone concentration is 215kg / m 3 .

[0096] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate is 63:20:15:2.

[0097] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 11.6 g / L.

[0098] 2) First extraction The first oxidation liquid is subjected to countercurrent extraction with low-concentration hydrogen peroxide, a crude hydrogen peroxide product with increased concentration is obtained from the lower part of the first extraction tower, and a second oxidation liquid is obtained from the upper part.

[0099] Specifically, the volume ratio of the first oxidizing liquid to the low-concentration hydrogen peroxide solution is 68:1.

[0100] Specifically, the concentration of the crude hydrogen peroxide with increased concentration was 42.2 wt %.

[0101] Specifically, the content of hydrogen peroxide in the second oxidizing liquid is 7.4 g / L.

[0102] Specifically, the operating temperature of the first extraction was 42°C.

[0103] Specifically, during the first extraction, the nitrogen pressure was maintained at 5 kPa.

[0104] 3) Second extraction The second oxidizing liquid is subjected to countercurrent extraction with a 0.15 g / L aqueous phosphoric acid solution to obtain low-concentration hydrogen peroxide from the lower part of the second extraction tower. The obtained low-concentration hydrogen peroxide is mixed with the first oxidizing liquid in step 2). After testing, the hydrogen peroxide content in the raffinate is 0.20 g / L.

[0105] Specifically, the concentration of the low-concentration hydrogen peroxide is 32.5 wt % and the stability is 97.9%.

[0106] Specifically, the volume ratio of the second oxidizing liquid to the 0.15 g / L phosphoric acid aqueous solution is 68:1.

[0107] Specifically, the operating temperature of the second extraction is 50°C.

[0108] 4) Refining The crude hydrogen peroxide is cooled to 25°C and then purified, coalesced and separated, and stripped in sequence to obtain a finished hydrogen peroxide product. A heavy aromatic solvent is selected for countercurrent contact with the crude hydrogen peroxide.

[0109] Specifically, the crude hydrogen peroxide was cooled to 25°C.

[0110] Specifically, during purification, the volume ratio of heavy aromatics to crude hydrogen peroxide was 60:1, and the nitrogen pressure was maintained at 5 kPa.

[0111] Specifically, the residence time for the coalescence separation was 6 min.

[0112] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0113] Specifically, the hydrogen peroxide content in the finished hydrogen peroxide product is 44.8wt% and the stability is 97.5%.

[0114] 5) Detection It was detected that the total organic carbon content in the crude hydrogen peroxide was 0.031wt%, which decreased to 0.027wt% after purification, and further decreased to 0.024wt% after agglomeration and separation. The total organic carbon content in the finished hydrogen peroxide obtained after gas stripping was 0.19wt%.

[0115] Table 2 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 2 that when the hydrogenation efficiency is reduced so that 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 the hydrogen peroxide product. 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.

[0116] Comparative Example 3 The difference between this comparative example and Example 1 is that in this comparative example, in step 4) of the refining section, no purification is performed, and the crude product of high-concentration hydrogen peroxide is directly subjected to agglomeration separation and gas stripping after cooling. 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 14.9 g / L.

[0117] The working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate as a mixed solvent, among which the anthraquinone concentration is 215kg / m 3 .

[0118] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and trioctyl phosphate is 63:20:15:2.

[0119] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 15.1 g / L.

[0120] 2) First extraction The first oxidation liquid is subjected to countercurrent extraction with low-concentration hydrogen peroxide, a crude hydrogen peroxide product with increased concentration is obtained from the lower part of the first extraction tower, and a second oxidation liquid is obtained from the upper part.

[0121] Specifically, the volume ratio of the first oxidizing liquid to the low-concentration hydrogen peroxide solution is 68:1.

[0122] Specifically, the concentration of the crude high-concentration hydrogen peroxide is 50.1 wt %.

[0123] Specifically, the content of hydrogen peroxide in the second oxidizing liquid is 9.4 g / L.

[0124] Specifically, the operating temperature of the first extraction was 42°C.

[0125] Specifically, during the first extraction, the nitrogen pressure was maintained at 5 kPa.

[0126] 3) Second extraction The second oxidizing liquid is subjected to countercurrent extraction with a 0.15 g / L aqueous phosphoric acid solution to obtain low-concentration hydrogen peroxide from the lower part of the second extraction tower. The obtained low-concentration hydrogen peroxide is mixed with the first oxidizing liquid in step 2). After testing, the hydrogen peroxide content in the raffinate is 0.20 g / L.

[0127] Specifically, the concentration of the low-concentration hydrogen peroxide solution is 39.1 wt % and the stability is 97.9%.

[0128] Specifically, the volume ratio of the second oxidizing liquid to the 0.15 g / L phosphoric acid aqueous solution is 68:1.

[0129] Specifically, the operating temperature of the second extraction is 50°C.

[0130] 4) Refining The high-concentration crude hydrogen peroxide is cooled to 25°C and then subjected to coalescence separation and gas stripping in sequence to obtain a finished hydrogen peroxide product. A heavy aromatic solvent is selected for purification and is contacted with the crude hydrogen peroxide product in countercurrent.

[0131] Specifically, the crude hydrogen peroxide was cooled to 25°C.

[0132] Specifically, during purification, the volume ratio of heavy aromatics to crude hydrogen peroxide was 60:1, and the nitrogen pressure was maintained at 5 kPa.

[0133] Specifically, the residence time for the coalescence separation was 6 min.

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

[0135] Specifically, the hydrogen peroxide content in the finished hydrogen peroxide product is 50.1wt%, and the stability is 97.5%.

[0136] 5) Detection It was detected that the total organic carbon content in the crude hydrogen peroxide was 0.033wt%, which was reduced to 0.029wt% after agglomeration and separation, and the total organic carbon content in the high-concentration hydrogen peroxide product obtained after gas stripping was 0.026wt%.

[0137] Table 3 Effect of purification process on total organic content in hydrogen peroxide product during refining From the data in Table 3, it can be seen that purification can reduce the total organic carbon content in high-concentration hydrogen peroxide to a certain extent, which is beneficial to improving the quality of high-concentration hydrogen peroxide products. Even without purification, the total organic carbon content of the high-concentration hydrogen peroxide products obtained can meet the requirements of the national standard GB / T1616-2014 "Industrial Hydrogen Peroxide" for superior products.

[0138] Comparative Example 4 The difference between this comparative example and Example 1 is that the first extraction of step 2) is not performed, and the first oxidizing liquid is directly subjected to countercurrent extraction with a 0.15 g / L phosphoric acid aqueous solution in the second extraction tower. Under the premise of ensuring safe production (i.e., the residue does not exceed 0.25 g / L), the extraction section is simulated and calculated, and the maximum concentration of hydrogen peroxide that can be obtained is 42.5 wt%.

[0139] 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 17.0 g / L.

[0140] The working fluid uses amyl anthraquinone as the working carrier, heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl methanol and methyl cyclohexyl acetate as a mixed solvent, among which the anthraquinone concentration is 235kg / m 3 .

[0141] Specifically, the volume ratio of heavy aromatic hydrocarbons, tetrabutyl urea, diisobutyl carbinol and methyl cyclohexyl acetate is 63:25:10:2.

[0142] Specifically, the hydrogenation efficiency of the hydrogenated liquid was 17.4 g / L.

[0143] The first oxidation liquid is subjected to countercurrent extraction with low-concentration hydrogen peroxide to obtain a high-concentration hydrogen peroxide crude product from the lower part of the first extraction tower, and the second oxidation liquid is obtained from the upper part.

[0144] Specifically, the volume ratio of the first oxidizing liquid to the low-concentration hydrogen peroxide solution is 62:1.

[0145] Specifically, the concentration of the crude high-concentration hydrogen peroxide is 51.0 wt %.

[0146] Specifically, the content of hydrogen peroxide in the second oxidizing liquid is 11.0 g / L.

[0147] Specifically, the operating temperature of the first extraction was 42°C.

[0148] Specifically, during the first extraction, the nitrogen pressure was maintained at 5 kPa.

[0149] 3) Second extraction The second oxidizing liquid is subjected to countercurrent extraction with a 0.15 g / L aqueous phosphoric acid solution to obtain low-concentration hydrogen peroxide from the lower part of the second extraction tower. The obtained low-concentration hydrogen peroxide is mixed with the first oxidizing liquid in step 2). After testing, the hydrogen peroxide content in the raffinate is 0.20 g / L.

[0150] Specifically, the concentration of the low-concentration hydrogen peroxide is 40.4 wt % and the stability is 97.7%.

[0151] Specifically, the volume ratio of the second oxidizing liquid to the 0.15 g / L phosphoric acid aqueous solution is 62:1.

[0152] Specifically, the operating temperature of the second extraction is 50°C.

[0153] 4) Refining The crude high-concentration hydrogen peroxide is cooled to 25°C and then purified, coalesced and separated, and stripped in sequence to obtain a high-concentration hydrogen peroxide product. The purification is performed by countercurrent contact of a heavy aromatic solvent with the high-concentration hydrogen peroxide.

[0154] Specifically, the crude high-concentration hydrogen peroxide solution is cooled to 25°C.

[0155] Specifically, during purification, the volume ratio of heavy aromatics to high-concentration hydrogen peroxide crude product was 60:1, and the nitrogen pressure was maintained at 5 kPa.

[0156] Specifically, the residence time for the coalescence separation was 6 min.

[0157] Specifically, during gas stripping, the volume ratio of liquid to air (standard) is 1:48.

[0158] Specifically, the hydrogen peroxide content in the high-concentration double water product is 50.1wt% and the stability is 97.3%.

[0159] 5) Detection It was detected that the total organic carbon content in the crude high-concentration hydrogen peroxide was 0.031wt%, which decreased to 0.025wt% after purification, and further decreased to 0.023wt% after agglomeration and separation. The total organic carbon content in the high-concentration hydrogen peroxide finished product obtained after gas stripping was 0.020wt%.

[0160] Comparative Example 5 The difference between this comparative example and Example 2 is that the first extraction of step 2) is not performed, and the first oxidizing liquid is directly subjected to countercurrent extraction with a 0.15 g / L phosphoric acid aqueous solution in the second extraction tower. Under the premise of ensuring safe production (i.e., the residue does not exceed 0.25 g / L), the extraction section is simulated and calculated, and the maximum concentration of hydrogen peroxide that can be obtained is 44.6 wt%.

[0161] Table 4 Effect of the first extraction process on the concentration of hydrogen peroxide finished product Whether to perform the first step of extraction Concentration of finished hydrogen peroxide (wt%) Example 1 yes 50.1 Comparative Example 4 no 42.5 (Simulation Calculation) Example 2 yes 51.0 Comparative Example 5 no 44.6 (Simulation Calculation) It can be seen from the data in Table 5 that, under the premise of ensuring that the residue does not exceed the standard, if the conventional oxidation liquid direct extraction method is adopted (that is, without the first extraction, the first oxidation liquid and weakly acidic water are directly countercurrently extracted), after simulation calculation, the maximum concentration of the hydrogen peroxide product that can be obtained is 44.6wt%, and it is impossible to produce a product with a concentration close to 50wt%.

[0162] 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.

[0163] 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 producing high-concentration hydrogen peroxide by extraction, characterized in that: The following steps are involved: s1. The working liquid is hydrogenated, oxidized and filtered to obtain a first oxidation liquid, wherein the hydrogen peroxide content in the first oxidation liquid is 12.5 to 20.0 g / L; s2. The first oxidation liquid is countercurrently extracted with a low concentration of hydrogen peroxide, the lower layer is a high concentration of crude hydrogen peroxide, the upper layer is a second oxidation liquid, the concentration of the low concentration of hydrogen peroxide is 36~42wt%, the content of hydrogen peroxide in the second oxidation liquid is 7.5~13.0g / L; s3. The weakly acidic water and the second oxidation liquid were countercurrently extracted to obtain a low concentration of 36 to 42wt% hydrogen peroxide, the low concentration of hydrogen peroxide and the first oxidation liquid in s2 were countercurrently extracted; s4. After cooling the crude high-concentration hydrogen peroxide, it is purified, agglomerated and separated, and gas-lifted in sequence to obtain a high-concentration hydrogen peroxide finished product.

2. A method for producing high-concentration hydrogen peroxide by extraction according to claim 1, characterized in that: In s1, the solute of the working fluid is ethyl anthraquinone and amyl anthraquinone or amyl anthraquinone, the solvent is a mixed solvent composed of non-polar heavy aromatic hydrocarbons and polar solvents, the polar solvent is diisobutyl carbinol, tetrabutyl urea, and / or methyl cyclohexyl acetate, trioctyl phosphate, and the anthraquinone concentration of the working fluid is 150~360kg / m3.

3. A method for producing high-concentration hydrogen peroxide by extraction according to claim 2, characterized in that: The volume ratio of heavy aromatics to polar solvents is 50:50~80:

20.

4. The method for producing high-concentration hydrogen peroxide by extraction according to claim 1, characterized in that: In s1, the hydrogenation efficiency during hydrogenation is 13.0~20.5g / L.

5. The method for producing high-concentration hydrogen peroxide by extraction according to claim 1, characterized in that: In s2, when the first oxidation liquid and low-concentration hydrogen peroxide are countercurrently extracted: The volume ratio of low-concentration hydrogen peroxide to the first oxidation liquid is 1:80~1:45; Temperature is 38~46℃; The reaction was carried out under nitrogen atmosphere with an operating pressure of 0.3~40 kPa.

6. The method for producing high-concentration hydrogen peroxide by extraction according to claim 1, characterized in that: In s3, when the second oxidation liquid and weakly acidic water are countercurrently extracted: The volume ratio of the first oxidation liquid to the weakly acidic water is 45:1 to 85:1; Temperature: 48~55℃; Weakly acidic water is a 0.1~0.4g / L phosphoric acid aqueous solution; The content of hydrogen peroxide in the raffinate is ≤0.25g / L The stability of low concentration hydrogen peroxide is ≥97.5%.

7. The method for producing high-concentration hydrogen peroxide by extraction according to claim 1, characterized in that: In s4, the cooling temperature is 15~35℃.

8. A method for producing high-concentration hydrogen peroxide by extraction according to claim 1 or 7, characterized in that: In s4, when purifying: The operating temperature is 15~35℃; The heavy aromatic solvent is contacted with the crude product of high concentration hydrogen peroxide in countercurrent; The volume ratio of heavy aromatics to high-concentration crude hydrogen peroxide is 45:1~70:1; The reaction was carried out under nitrogen atmosphere with an operating pressure of 0.3~40 kPa.

9. A method for producing high-concentration hydrogen peroxide by extraction according to claim 1 or 7, characterized in that: In s4, the operating temperature of the coalescence separation is 15~35℃; The action time of coagulation and separation is 2~15min.

10. The method for producing high-concentration hydrogen peroxide by extraction according to claim 1, characterized in that: The temperature of gas stripping is 15~35℃; The operating pressure is 0.5~1.0MPaG; The volume ratio of liquid to air is 1:20~1:65.

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