Working solution for production of hydrogen peroxide by anthraquinone method

Abstract

The application discloses a working solution for producing hydrogen peroxide by an anthraquinone method, which comprises a solvent and a working carrier, wherein the solvent comprises p-phenylenediacetamide derivative A and heavy aromatic hydrocarbon, the heavy aromatic hydrocarbon is generally C7-C 10 The solvent comprises 5-50 parts of p-phenylenediacetamide derivative A and 30-95 parts of heavy aromatic hydrocarbon, preferably 10-30 parts and 60-80 parts respectively; and the working carrier is one or more of anthraquinone and its derivatives, preferably 2-alkyl anthraquinone, and further preferably 2-ethyl anthraquinone, 2-butyl anthraquinone or 2-pentyl anthraquinone. The working solution has good solubility for anthraquinone and hydrogen anthraquinone, low mutual solubility with water, stable physical and chemical properties, and can meet the use requirements of the anthraquinone method process, improve the production efficiency of the anthraquinone method process for producing hydrogen peroxide, and has a good industrial application prospect.

Description

Technical Field

[0001] This invention pertains to hydrogen peroxide preparation technology, specifically relating to a working solution for the anthraquinone process in the production of hydrogen peroxide. Background Technology

[0002] Since my country successfully developed its first hydrogen peroxide production unit in 1987, the anthraquinone synthesis technology has been used ever since. This process generally uses 2-alkylanthraquinone as the carrier for the H2 and O2 reaction, which is then reacted with an organic solvent to form a working solution. The working solution is subjected to alternating hydrogenation and oxidation reactions, and finally the organic working solution is extracted to obtain an aqueous H2O2 solution (commonly known as hydrogen peroxide).

[0003] Due to the differences in molecular properties and solubility of anthraquinones and their hydrogenation products, a single solvent is generally insufficient to fully meet the performance requirements of the working fluid. Solvents typically consist of anthraquinone solvents and hydrogenated anthraquinone solvents. Anthraquinone solvents are generally C44-445 ... 7～ C 10 Aromatic hydrocarbons (AR) and anthraquinone solvents are the core factors affecting the performance of the working fluid. They are mainly selected from higher fatty alcohols, organic acids or inorganic acid esters, such as trioctyl phosphate (TOP).

[0004] The existing industrial aromatic hydrocarbon + trioctyl phosphate working solution (AR / TOP) has the following main technical problems: (1) The solubility of anthraquinone and hydroanthraquinone is low, resulting in low anthraquinone conversion rate, large working solution circulation volume, and small operational flexibility. Under normal temperature conditions, the solubility of AR / TOP working solution for 2-ethylanthraquinone is only 130-150 g / L, and under operating conditions, the solubility of hydroanthraquinone is only 55-60 g / L. In order to avoid the precipitation of hydroanthraquinone crystals, which would lead to the deterioration of the physicochemical properties of the working solution, the industry usually controls the anthraquinone conversion rate at a low level (generally below 40%); (2) The hydrogenation efficiency of the working solution is low, resulting in low hydrogen peroxide product concentration, which limits the production efficiency of the equipment and leads to high production costs. Currently, the hydrogenation efficiency of domestic hydrogen peroxide industrial equipment is generally lower than 8.5 g / L. It relies on the huge circulation volume of the working fluid in the reaction system to meet the production load requirements of the equipment. This places stringent requirements on the power equipment load and reactor structure. Not only is the engineering difficult, but the energy consumption and investment are also high. Moreover, the concentration of the hydrogen peroxide produced is low. It needs to be further purified and concentrated to meet the quality concentration requirements of hydrogen peroxide in processes such as the direct oxidation of propylene / hydrogen peroxide to produce propylene oxide (HPPO) and the ammoniation of cyclohexanone to produce caprolactam. If the hydrogenation efficiency of the working fluid is improved, under the same working conditions, not only can the circulation volume of the working fluid be significantly reduced, but the product purification and concentration process can also be avoided, reducing the production costs and safety hazards that follow. (3) The working fluid is severely degraded, resulting in low quality grade of hydrogen peroxide products and high consumption of anthraquinone, which cannot meet the demand for high-purity hydrogen peroxide products. The presence of degradation products in the working fluid not only causes the loss of effective anthraquinone, increasing anthraquinone consumption, but also significantly deteriorates the physicochemical properties of the working fluid, leading to poorer fluidity, reduced interfacial tension, and a tendency for flooding in the extraction tower. The working fluid is difficult to coagulate within the extraction tower, resulting in water carryover in the raffinate. The increased viscosity of the working fluid increases flow resistance, affecting separation in the extraction tower. The increased density of the working fluid reduces the density difference between the working fluid and water, causing the working fluid to co-dissolve with water in the extraction tower, making separation difficult and further resulting in more impurities in the product.

[0005] Based on the AR / TOP binary working solution, CN1552618A discloses a ternary working solution of aromatic hydrocarbon + trioctyl phosphate + methyl cyclohexyl acetate (AR / TOP / MCHA). Compared with the traditional AR / TOP working solution, the AR / TOP / MCHA working solution system can increase the solubility of 2-ethylanthraquinone by 30 g / L, and the hydrogenation efficiency of the working solution can be increased to 8.7-9.5 g / L. CN1583546A discloses a ternary working solution of aromatic hydrocarbon + trioctyl phosphate + tetrabutylurea (AR / TOP / TBU), which increases the solubility of hydroanthraquinone by nearly 10% compared with the AR / TOP working solution, and the hydrogenation efficiency of the working solution is slightly improved. CN101798065A also discloses a ternary working solution of aromatic hydrocarbon + trioctyl phosphate + N-phenyl-N-ethylbenzamide, which increases the solubility of hydroanthraquinone by nearly 10-20% compared with the AR / TOP working solution, and the hydrogenation efficiency can reach 11-12 g / L. / L; EP0287421 discloses an aromatic hydrocarbon + N-phenyl N-ethylbenzamide (AR / BEA) binary working solution. Although this system significantly improves the solubility of anthraquinone and hydroanthraquinone, the working solution formed with anthraquinone has a high density and high water solubility, resulting in poor hydrogen peroxide extraction and separation effect and high carbon residue in the hydrogen peroxide product; US4803063 discloses an aromatic hydrocarbon + N-phenyl N-ethylbenzamide binary working solution. The solvent system has good solubility for both 2-alkylanthraquinone and 2-alkyl hydroanthraquinone, achieving good hydrogenation efficiency and good oxidation stability. However, the solvent system has a long separation and demulsification time with water, which seriously affects the separation efficiency of the extraction tower. In severe cases, the working solution carries water, affecting the hydrogenation efficiency of the catalyst in the hydrogenation process, resulting in poor application effect and failing to meet the application requirements of the hydrogen peroxide industry; CN111071993A discloses a working solution solvent molecule with the following diamide structure. The solvent system composed of this solvent and aromatic hydrocarbons also has good solubility for both 2-alkylanthraquinone and 2-alkylhydroanthraquinone, achieving good hydrogenation efficiency. The solvent system has a short separation and demulsification time with water, which can well meet the requirements of industrial use. However, the solvent degradation loss needs to be improved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention proposes a working solution for the synthesis of hydrogen peroxide via the anthraquinone process. This system exhibits good solubility for both anthraquinone and hydroanthraquinone, low miscibility with water, and stable physicochemical properties. It meets the requirements of the anthraquinone process, improves the production efficiency of hydrogen peroxide production via the anthraquinone process, and has promising prospects for industrial application.

[0007] The working solution for the anthraquinone method of hydrogen peroxide synthesis of the present invention includes a solvent and a working carrier, wherein the solvent includes terephthalamide derivative A and a heavy aromatic hydrocarbon, wherein the structural formula of terephthalamide derivative A is: R1, R2, R3, and R4 are alkane substituents, furan, benzyl, or aromatic substituents with 1 to 8 carbon atoms, respectively. These alkane, furan, benzyl, or aromatic substituents may also contain one or more functional groups selected from alkyl, alkoxy, and ester groups. R1 to R4 are preferably C1 to C6 alkyl substituents. The number of carbon atoms in the substituents at different positions can be adjusted according to the different physicochemical properties required by the working fluid, but the total number of carbon atoms is generally not higher than 20. The heavy aromatic hydrocarbons are generally C7 to C8. 10 Aromatic hydrocarbons; the solvent, by volume, comprises 5 to 50 parts of terephthalamide derivative A, preferably 10 to 30 parts, and 30 to 95 parts of heavy aromatic hydrocarbons, preferably 60 to 80 parts.

[0008] The working carrier is one or more of anthraquinone and its derivatives, preferably 2-alkylanthraquinone, and more preferably 2-ethylanthraquinone, 2-butylanthraquinone, or 2-pentylanthraquinone.

[0009] The method for synthesizing terephthalamide derivative A of the present invention includes the following steps:

[0010] (1) Dissolve terephthalic acid in organic solvent B. Under the action of acyl chloride C, the hydroxyl functional group of terephthalic acid is replaced by chlorine atoms to generate dicarboxylic acid acyl chloride D. After the reaction, the product is separated by vacuum distillation to obtain terephthalic acid acyl chloride D. (2) Dissolve terephthalic acid acyl chloride D obtained in step (1) in organic solvent E, and add appropriate amounts of triethylamine and dialkylamine F1 or F2 or a mixture of F1 and F2. Under certain temperature conditions, carry out an amidation reaction to obtain crude product terephthalamide derivative A. (3) After the reaction solution in step (2) is cooled to room temperature, filter out the small amount of insoluble matter generated during the reaction. Wash the reaction solution with hydrochloric acid, sodium carbonate solution and deionized water until neutral. Let it stand to separate the lower organic phase. Then separate and purify the product to obtain the target product terephthalamide derivative A.

[0011] In the method of this invention, the dehydration reaction formula in step (1) is as follows (taking phosphate acyl chloride PCl5 as an example):

[0012]

[0013] In the method of the present invention, the organic solvent B in step (1) is selected from one or more of chlorobenzene, dichloromethane, chloroform, N,N-dimethylformamide or ethyl acetate, and the molar ratio of the organic solvent to terephthalic acid is 1:1.5 to 75, preferably 2 to 30.

[0014] In the method of the present invention, the acyl chloride C in step (1) is one or more of phosphoric acid acyl chloride PCl5, phosphorous acid acyl chloride PCl3, and sulfite acyl chloride SOCl2, and the molar ratio of acyl chloride C to terephthalic acid is 1:1 to 20, preferably 2 to 8.

[0015] In the method of this invention, the reaction conditions in step (1) are: atmospheric pressure, 100-120℃ for 2-4 hours. After the reaction is completed, the reactants are cooled to a temperature range of 40-50℃. First, the organic solvent B is separated by vacuum distillation. Then, the temperature is increased to a temperature range of 75-78℃ and the acyl chloride C is separated by vacuum distillation under negative pressure (e.g., -0.1 to -0.03 MPa). Finally, the intermediate product p-phenylenedicarboxylic acid acyl chloride D is separated from the product.

[0016] In the method of the present invention, the reaction formula in step (2) is as follows:

[0017]

[0018] In the method of the present invention, the dialkylamines F1 and F2 mentioned in step (2) are wherein R1, R2, R3, and R4 are one of furan, aromatic substituents, benzyl or alkane substituents, and the furan, aromatic substituents, benzyl or alkane substituents may also contain one or more functional groups of alkyl, alkoxy, and ester groups.

[0019] In the method of the present invention, the organic solvent E in step (2) is selected from chlorobenzene, dichloromethane or trichloromethane, and the molar ratio of organic solvent E to terephthalic acid acyl chloride D is 1:1.5 to 100, preferably 2 to 30.

[0020] In the method of the present invention, the molar ratio of dialkylamines F1 and F2 to terephthalic acid acyl chloride D in step (2) is 1:1:0.5-1. Terephthalic acid acyl chloride D can be mixed with dialkylamine and triethylamine at once, or added dropwise to the mixture.

[0021] In the method of the present invention, the reaction conditions in step (2) are 50-120°C and normal pressure, and the reaction solution is reacted in a reflux reactor for 0.5-4 hours to obtain a crude product mixture containing terephthalamide derivative A.

[0022] In the method of the present invention, the washing in step (3) generally involves washing the reaction mixture 2 to 4 times with hydrochloric acid, sodium carbonate solution and deionized water, so that the reaction solution is finally neutral.

[0023] In the method of the present invention, the separation and purification method described in step (3) is vacuum distillation, adsorption separation or extraction, etc.

[0024] This invention also provides a hydrogenation process for producing hydrogen peroxide using the anthraquinone process, which employs the aforementioned working fluid. The hydrogenation reactor can be a fluidized bed, slurry bed, or fixed bed. The hydrogenation process conditions are: hydrogenation temperature 25–80°C, pressure 0.1–0.7 MPa. The hydrogenation process can utilize hydrogenation catalysts well-known in the field of anthraquinone processes. The active hydrogenation component is generally Pd, and the support is generally alumina or silica gel. Additive components, such as one or more of Mo, Na, K, Ni, Mg, Au, Ca, and Fe, can also be added to the catalyst. Based on the weight of the hydrogenation catalyst components, the content of the active hydrogenation component is 0.05%–5%, and the content of the additive is 0.05%–3%.

[0025] The hydrogen peroxide working solution provided by this invention, when used in the anthraquinone process for producing hydrogen peroxide, allows for the oxidation step to utilize air, pure oxygen, or other conventional oxidants, with air being preferred. The typical process conditions for the oxidation step are: oxidation temperature of 25–70°C and pressure of 0.1–0.5 MPa.

[0026] Compared with the prior art, the working fluid of the present invention has the following advantages: (1) Good solubility for anthraquinone: Under the anthraquinone process conditions, the solubility of the working fluid for 2-alkyl anthraquinone can be increased by nearly 50% compared with the existing industrial working fluid; (2) High solubility for anthraquinone: Under room temperature conditions, the solubility of this binary solvent for 2-ethyl anthraquinone is more than 180 g / L, which is more than 20% higher than the existing industrial working fluid, which can significantly improve the hydrogenation efficiency of the working fluid and inhibit the degradation reaction of anthraquinone; (3) High hydrogenation efficiency: Under the above hydrogenation catalyst and hydrogenation conditions, the hydrogenation efficiency of the 2-ethyl anthraquinone working fluid can reach more than 13 g / L, and the hydrogenation efficiency of the 2-pentyl anthraquinone working fluid can reach more than 16 g / L; (4) Good antioxidant properties of the working fluid, low solvent decomposition rate, and low residual carbon in hydrogen peroxide products, which can improve the production capacity and utilization efficiency of the anthraquinone process hydrogen peroxide plant. Detailed Implementation

[0027] The present invention will be further described below with reference to specific preferred embodiments, but this does not limit the scope of protection of the present invention. The performance evaluation method for the working fluid is as follows:

[0028] Evaluation method for hydrogenation test: Catalytic hydrogenation of anthraquinone working solution was carried out in a 500 mL mechanically stirred reactor at a hydrogenation temperature of 55℃, a hydrogenation pressure of 0.3 MPa, and a stirring rate of 400 rpm. The resulting hydrogenated solution was oxidized with air at atmospheric pressure and 50℃ for 1 hour. The oxidized solution was extracted four times using a separatory funnel, and the concentration of hydrogen peroxide in the extract was determined by potassium permanganate titration. The hydrogenation efficiency was calculated. The catalyst used in the hydrogenation test was a conventional Pd / Al₂O₃ catalyst with a particle size of 0.4–0.5 mm and a pore volume of 0.6–0.7 cm⁻¹. 3 / g, specific surface area 150~180m²2 / g, with a Pd content of 0.25wt% to 0.35wt%.

[0029] Hydrogenation efficiency analysis method: After the working solution undergoes catalytic hydrogenation, 5 mL of the hydrogenated solution is promptly transferred to a separatory funnel using a precision pipette. The hydrogenated solution is diluted with 50 mL of heavy aromatic hydrocarbons, 100 mL of ultrapure water, and 15 mL of 22.5% (w / w) dilute sulfuric acid solution. High-purity air is then introduced into the separatory funnel to fully oxidize the hydrogenated solution under normal temperature and pressure conditions. After 15 min of full oxidation with 2-ethylanthraquinone working solution and 25 min of full oxidation with 2-pentylanthraquinone working solution, the oxidized solution is extracted with ultrapure water. After three parallel extractions, the concentration of hydrogen peroxide in the extract is analyzed by potassium permanganate titration. Before titration, the potassium permanganate solution needs to be prepared and its concentration standardized. Accurately weigh 3.4g of potassium permanganate crystals, dissolve them in 1000mL of ultrapure water, place them in a brown bottle and let them stand for 5-7 days. After filtering the supernatant through a sintered glass funnel, the concentration of the supernatant is determined by sodium oxalate (Na2C2O4). Accurately weigh 0.20g of Na2C2O4, dry it at 110℃ for 2 hours, dissolve it in 30mL of ultrapure water and 25mL of 22.5% dilute sulfuric acid solution, heat the mixture to 85℃, and titrate the potassium permanganate solution while it is hot. When the titrant remains pink for 30s without fading, it is considered the titration endpoint. Record the amount of potassium permanganate consumed, and calculate the concentration of the potassium permanganate solution (C) using equations (1) and (2), respectively. KmnO4 ) and the hydrogenation efficiency (η) of the working fluid:

[0030]

[0031]

[0032] Method for determining the solubility of 2-alkylanthraquinone: Place a 500 mL three-necked flask in a constant temperature water bath, maintaining the water bath temperature at 25℃ ± 0.1℃; [The remaining text appears to be a fragmented and incomplete description of a flask, possibly related to a C9-C product. A more coherent translation would require the full context.] 10 Aromatic hydrocarbons and terephthalamide derivative A were prepared into 200 mL test solvents at volume fractions of 70 / 30, 75 / 25, and 80 / 20, respectively, and added to a three-necked flask at once. Under constant temperature conditions, the anthraquinone to be tested was gradually dissolved at a rate of 5 mg / min until the anthraquinone no longer dissolved. The total amount of anthraquinone dissolved was recorded, and the solubility of anthraquinone in different solvent systems was calculated.

[0033] Method for determining the solubility of 2-alkylanthraquinone: Different working solutions containing 2-ethylanthraquinone or 2-pentylanthraquinone were subjected to hydrogenation reaction in a transparent, visualized fixed-bed reaction tube at a reaction temperature of 55℃ and a reaction pressure of 0.1–0.3 MPa. The flow state of the working solution was monitored. When the working solution reached a turbid state (critical precipitation state), the hydrogenation reaction was stopped. The composition of the working solution at this point was analyzed by high-performance liquid chromatography (HPLC), and the hydrogenation efficiency of anthraquinone was determined simultaneously. Under the condition that no obvious degradation products were detected in the HPLC results, the solubility of 2-alkylanthraquinone in the solvent system was calculated based on the hydrogenation efficiency value.

[0034] Method for analyzing the extraction partition coefficient of the working solution: The liquid-liquid equilibrium analysis method was performed according to GB / T 1616-2014. A ternary system (working solution-pure water-hydrogen peroxide) of a certain concentration was thoroughly mixed in a 250 mL constant-temperature volumetric flask with a glass jacket. After standing for 2.5 hours under constant temperature conditions, the inorganic aqueous phase and the organic working solution phase were separated. The hydrogen peroxide content in the former was directly determined by potassium permanganate titration, and the organic working solution content was analyzed by a TOC residual carbon analyzer. The latter was extracted three times with pure water at the same temperature, and the hydrogen peroxide content was analyzed by the same method, while the pure water content was analyzed by a Karl Fischer moisture analyzer. After three parallel experiments, the mass concentration ratio of hydrogen peroxide in the aqueous phase to the organic phase of the working solution was taken as the extraction partition coefficient.

[0035] Analysis method for antioxidant properties of working solution: Air was introduced into a 500 mL mechanically stirred reactor to oxidize the working solution. The oxidation temperature was 150–200 °C, the oxidation pressure was 0.1–0.15 MPa, and the stirring rate was 400 rpm. After 150 h of oxidation reaction, the components of the working solution were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS), and the decomposition rate of terephthalamide derivative A before and after the oxidation reaction was calculated.

[0036] Example 1

[0037] Taking the synthesis process of N,N,N',N'-tetrabutylterephthalamide as an example:

[0038]

[0039] In a 500 mL reactor, 116 g of 1,4-phenylenediacetic acid, 150 mL of dichloromethane, and 250 g of PCl5 were added in a single batch. The system temperature was raised to 100 °C, and the reactants were thoroughly dissolved under vigorous stirring. After maintaining the system temperature for 2 hours, the reaction was stopped, and the system was allowed to cool naturally to 40–50 °C. The reactants were then transferred to a distillation vessel, and the reaction solution was subjected to vacuum distillation at this temperature. Further vacuum distillation was then carried out at -0.1 MPa and 75–78 °C to separate dichloromethane and PCl5. Finally, the system temperature was further increased to 128–132 °C to obtain the fraction in this temperature range as phenylenediacetyl chloride. In another 500 mL reactor, 258.5 g of dibutylamine and 15 g of PCl5 were added in a single batch. 0 mL of triethylamine was added to the reaction vessel, followed by phenylacetyl chloride. After thorough stirring until the reactants were uniformly mixed, the reaction was carried out under normal pressure, 100 °C, and reflux for 2 hours. After the reaction, the reaction solution was washed four times with 22.5 wt.% hydrochloric acid, 30 wt.% sodium carbonate aqueous solution, and pure water to make the reaction solution neutral. The reaction solution was then transferred to a distillation vessel and distilled under reduced pressure at -0.1 MPa to obtain the target product at 205–208 °C. The obtained product was confirmed by 1H NMR and MS spectral analysis to be N,N,N',N'-tetrabutylphenylacetamide, with a yield of 94.1%.

[0040] 1H NMR (500MHz, CDCl3) δ=0.92~0.97(m, 12H), 1.30~1.38(m, 8H), 1.47~1.54(m, 8H), 3.18~3.24(m, 8H), 3.58~3.62(m, 4H), 7.20~7.23(m, 4H); MS[M+H] + :412.1.

[0041] Example 2

[0042] Taking the synthesis process of N,N,N',N'-tetraethylterephthalamide as an example:

[0043]

[0044] In a 500 mL reactor, 58 g of 1,4-phenylenediacetic acid, 100 mL of dichloromethane, and 125 g of PCl5 were added in a single batch. The system temperature was raised to 100 °C, and the reactants were thoroughly dissolved under stirring. After maintaining the system temperature for 2 hours, the reaction was stopped, and the system was allowed to cool naturally to 40–50 °C. The reactants were then transferred to a distillation vessel, and the reaction solution was subjected to vacuum distillation at this temperature. Dichloromethane and PCl5 were then separated by vacuum distillation at -0.1–0.03 MPa and 75–78 °C. Finally, the system temperature was further increased to 128–132 °C to obtain the fraction in this temperature range, which is phenylenediacetyl chloride. In another 500 mL reactor, 130 g of diethylamine and 100 mL of triethylamine were added in a single batch, followed by the addition of phenylenediacetyl chloride to the reactor. In a reaction vessel, the reactants were thoroughly stirred until homogeneous, and then reacted for 2 hours under normal pressure, 100°C, and reflux. After the reaction, the reaction solution was washed four times with 22.5 wt.% hydrochloric acid, 30 wt.% sodium carbonate aqueous solution, and pure water to make the solution neutral. The reaction solution was then transferred to a distillation vessel and subjected to vacuum distillation at -0.1 to -0.03 MPa to obtain the target product at 205–208°C. The product was confirmed by 1H NMR and MS spectral analysis to be N,N,N',N'-tetraethylphenyl diacetamide, with a yield of 95.7%.

[0045] 1H NMR (500MHz, CDCl3) δ=0.92~0.97(m, 12H), 1.33~1.38(m, 8H), 1.41~1.49(m, 8H), 3.21~3.26(m, 8H), 3.58~3.62(m, 4H), 7.20~7.23(m, 4H); MS[M+H] + :301.4.

[0046] Example 3

[0047] A working fluid for the anthraquinone process in hydrogen peroxide production includes C7 to C8. 10 Aromatic hydrocarbons, N,N,N',N'-tetraethylterephthalamide, and 2-ethylanthraquinone, wherein the N,N,N',N'-tetraethylterephthalamide is prepared by the method of Example 1. The binary solvent, by volume, is C7-C6 10 Aromatic hydrocarbons: N,N,N',N'-tetraethylterephthalamide = 75:25, prepared as a working solution with a 2-ethylanthraquinone mass concentration of 180 g / L; analytical results show that C7~C 10The oxidative decomposition rate of aromatic hydrocarbons and N,N,N',N'-tetraethylterephthalamide binary solvent was 11.3%. The solubility of the working solution in 2-ethylhydroanthraquinone was 95.5 g / L. The hydrogenation efficiency at 55℃ and 0.3 MPa was 13.2 g / L. The organic residual carbon in the hydrogen peroxide product was 101.9 ppm. The separation and demulsification time of the working solution and pure water was 37 s.

[0048] Example 4

[0049] A working fluid for the anthraquinone process in hydrogen peroxide production includes C7 to C8. 10 Aromatic hydrocarbons, N,N,N',N'-tetraethylterephthalamide, and 2-pentylanthraquinone. Binary solvent, by volume, C7–C6 10 Aromatic hydrocarbons: N,N,N',N'-tetraethylterephthalamide = 75:25 were used to prepare a working solution with a 2-pentylanthraquinone mass concentration of 300 g / L; analytical results showed that C7~C 10 The oxidative decomposition rate of the binary solvent of aromatic hydrocarbons and N,N,N',N'-tetraethylterephthalamide was 11.3%. The solubility of the working solution for 2-pentylhydroanthraquinone was 135.2 g / L. The hydrogenation efficiency at 55℃ and 0.3 MPa was 17.7 g / L. The organic residual carbon in the hydrogen peroxide product was 100.6 ppm. The separation and demulsification time of the working solution and pure water was 40 s.

[0050] Example 5

[0051] A working fluid for the anthraquinone process in hydrogen peroxide production includes C7 to C8. 10 Aromatic hydrocarbons, N,N'-methoxy-N,N'-dipropylterephthalamide, and 2-ethylanthraquinone. Binary solvent, by volume, C7–C6 10 Aromatic hydrocarbons: N,N'-methoxy-N,N'-dipropylterephthalamide = 80:20, prepared as a working solution of 2-ethylanthraquinone with a mass concentration of 180 g / L; analytical results show that C7~C 10 The oxidative decomposition rate of aromatic hydrocarbons and N,N'-methoxy-N,N'-dipropylterephthalamide diethyl solvent was 9.5%. The solubility of the working solution in 2-ethylhydroanthraquinone was 96.3 g / L. The hydrogenation efficiency at 55℃ and 0.3 MPa was 13.2 g / L. The organic residual carbon in the hydrogen peroxide product was 115.9 ppm. The separation and demulsification time of the working solution and pure water was 41 s.

[0052] Example 6

[0053] A working fluid for the anthraquinone process in hydrogen peroxide production includes C7 to C8. 10 Aromatic hydrocarbons, N,N'-benzyl-N,N'-diethylterephthalamide, and 2-pentylanthraquinone. Binary solvents, by volume, C7–C6 10Aromatic hydrocarbons: N,N'-benzyl-N,N'-diethylterephthalamide = 60:40, prepared as a working solution with a 2-pentylanthraquinone mass concentration of 275 g / L; analytical results show that C7~C 10 The oxidative decomposition rate of the binary solvent of aromatic hydrocarbons and N,N'-benzyl-N,N'-diethylterephthalamide was 12.8%. The solubility of the working solution in 2-ethylhydroanthraquinone was 143.5 g / L. The hydrogenation efficiency at 55℃ and 0.3 MPa was 18.2 g / L. The organic residual carbon in the hydrogen peroxide product was 111.2 ppm. The separation and demulsification time of the working solution and pure water was 35 s.

[0054] Example 7

[0055] A working fluid for the anthraquinone process in hydrogen peroxide production includes C7 to C8. 10 Aromatic hydrocarbons, N,N,N',N'-tetrabutylterephthalamide, and 2-ethylanthraquinone. Binary solvent, by volume, C7–C6 10 Aromatic hydrocarbons: N,N,N',N'-tetrabutylterephthalamide = 70:30 were used to prepare a working solution with a 2-ethylanthraquinone mass concentration of 190 g / L; analytical results showed that C7~C 10 The oxidative decomposition rate of the binary solvent of aromatic hydrocarbons and N,N,N',N'-tetrabutylterephthalamide was 12.1%. The solubility of the working solution in 2-ethylhydroanthraquinone was 96.9 g / L. The hydrogenation efficiency at 55℃ and 0.3 MPa was 13.7 g / L. The organic residual carbon in the hydrogen peroxide product was 99.8 ppm. The separation and demulsification time of the working solution and pure water was 33 s.

[0056] Comparative Example 1

[0057] Measured by volume fraction, in C7~C 10 A 75 / 25 mixture of aromatic hydrocarbons and trioctyl phosphate was used as the solvent system to prepare a 2-ethylanthraquinone working solution. The performance of this working solution system was analyzed using the method described above. Experimental results showed that 2-ethylanthraquinone, under 25℃ and normal pressure conditions, exhibits good performance at C7~C80℃. 10 The solubility of 2-ethylanthraquinone in the aromatic hydrocarbon / trioctyl phosphate working solution system is 123–130 g / L. The solubility of 2-ethylanthraquinone is 68.5–70 g / L at 53–60℃ and 0.25–0.30 MPa. The hydrogenation efficiency of the working solution with a 2-ethylanthraquinone mass concentration of 125 g / L is 6.5–7.3 g / L. The degradation rate of trioctyl phosphate is 29.8%. The organic residual carbon in the hydrogen peroxide product is 355 ppm. The separation and demulsification time of the working solution and pure water is 31 s.

[0058] Comparative Example 2

[0059] The working solution was prepared according to Example 3 of CN1552618A, and its performance was analyzed as described above. The experimental results showed that, under conditions of 53–60℃ and 0.25–0.30 MPa, the working solution with a 2-ethylanthraquinone mass concentration of 154 g / L had a solubility of 51.5–53.1 g / L for hydrogen anthraquinone, a hydrogenation efficiency of 7.4–7.8 g / L, a degradation rate of 33.1%, an organic residual carbon content of 851 ppm in the hydrogen peroxide product, and a separation and demulsification time of 33 s between the working solution and pure water.

[0060] Comparative Example 3

[0061] A 2-ethylanthraquinone working solution was prepared according to the binary solvent system of aromatic hydrocarbon + N-phenyl-N-ethylbenzamide (BEA) disclosed in EP0287421. The performance of this working solution system was analyzed as described above. Experimental results showed that the solubility of 2-ethylanthraquinone in the working solution system was 155–163 g / L at 25℃ and atmospheric pressure, and 85–89 g / L at 55–60℃ and 0.25–0.30 MPa. The hydrogenation efficiency of the working solution with a 2-ethylanthraquinone mass concentration of 150 g / L was 10.33 g / L. The organic residual carbon in the hydrogen peroxide product was 1031 ppm. The oxidative decomposition rate of the solvent during 120 hours of oxidation was 12.9%. The separation and demulsification time between the working solution and pure water was 72 s.

[0062] Comparative Example 4

[0063] A 2-ethylanthraquinone working solution was prepared according to the binary solvent system of aromatic hydrocarbon + N,N-dibutyl-N',N'-diethylbutanediamide disclosed in CN111071993A. The performance of this working solution system was analyzed using the method described above. The experimental results show that the solubility of 2-ethylanthraquinone in this working solution system is 165 g / L at 25℃ and normal pressure; the solubility of 2-ethylhydroanthraquinone is 94.5 g / L at 55–60℃ and 0.25–0.30 MPa; the hydrogenation efficiency of the working solution with a 2-ethylanthraquinone mass concentration of 150 g / L is 10.33 g / L; the organic residual carbon in the hydrogen peroxide product is 129.6 ppm; the solvent oxidation decomposition rate is 17.3%; and the separation and demulsification time between the working solution and pure water is 41 s.

[0064] Comparative Example 5

[0065] A 2-ethylanthraquinone working solution was prepared according to the binary solvent system of aromatic hydrocarbon + N-phenyl-N-ethylbenzamide disclosed in US4803063, and its performance was analyzed as described above. The experimental results showed that the solubility of 2-ethylanthraquinone in the working solution system was 158.5 g / L at 25℃ and normal pressure, and 83.1 g / L at 55–60℃ and 0.25–0.30 MPa. The hydrogenation efficiency of the working solution with a 2-ethylanthraquinone mass concentration of 150 g / L was 10.33 g / L. The organic residual carbon in the hydrogen peroxide product was 133.4 ppm. The oxidative decomposition rate of the solvent during 120 hours of oxidation was 12.1%, and the separation and demulsification time between the working solution and pure water was 63 s.

Claims

1. A working solution for the production of hydrogen peroxide by the anthraquinone process, comprising a solvent and a working carrier, characterized in that: The solvent comprises p-xylylene diamide derivative A and heavy aromatic hydrocarbon, wherein the structural formula of p-xylylene diamide derivative A is: wherein R1, R2, R3, R4 are respectively one of alkyl substituent with 1-8 carbon atoms, furan, benzyl or aromatic hydrocarbon substituent; the total carbon atom number of R1, R2, R3, R4 is not higher than 20; the heavy aromatic hydrocarbon is C7-C 10 Aromatic hydrocarbon; the solvent comprises p-xylylene diamide derivative A 5-50 parts and heavy aromatic hydrocarbon 30-95 parts in volume fraction.

2. The working fluid of claim 1, wherein: The alkyl, alkoxy, ester group is one or more functional groups contained in the alkyl substituent, furan, benzyl or aromatic hydrocarbon substituent.

3. The working fluid of claim 1, wherein: R1-R4 are C1-C6 alkyl substituents.

4. The working fluid of claim 1, wherein: The working carrier is one or more of anthraquinone and its derivatives.

5. The working fluid of claim 1, wherein: The synthesis method of the p-phenylenediacetamide derivative A comprises the following steps: (1) dissolving p-phenylenediacetic acid in an organic solvent B, and substituting the hydroxyl functional groups of the p-phenylenediacetic acid with chlorine atoms under the action of acyl chloride C to generate dicarboxylic acid chloride D, and after the reaction is completed, separating the p-phenylenedicarboxylic acid chloride D by vacuum distillation; (2) dissolving the p-phenylenedicarboxylic acid chloride D obtained in step (1) in an organic solvent E, adding appropriate amount of triethylamine and dialkylamine F1 or F2 or the mixture of F1 and F2, and performing amidation reaction under certain temperature conditions to obtain the p-phenylenediamide derivative A crude product; (3) finally separating and purifying to obtain the p-phenylenediacetamide derivative A.

6. The working fluid of claim 5, wherein: The organic solvent B in step (1) is selected from one or more of chlorobenzene, dichloromethane, trichloromethane, N, N-dimethylformamide or ethyl acetate, and the molar ratio of the organic solvent A to p-phenylenediacetic acid is 1:1.5-75.

7. The working fluid of claim 5, wherein: The acyl chloride C in step (1) is one or more of phosphorus oxychloride PCl5, phosphorous oxychloride PC13 or sulfurous acid chloride SOCl2, and the molar ratio of the acyl chloride C to p-phenylenediacetic acid is 1:1-20.

8. The working fluid of claim 5, wherein: The reaction condition in step (1) is that the reaction is carried out under normal pressure and at 100-120℃ for 2-4 hours.

9. The working fluid of claim 5, wherein: After the reaction in step (1) is completed, the reactants are cooled to 40-50℃, first the organic solvent B is separated by vacuum distillation; then the temperature is increased to 75-78℃, and the acyl chloride C is separated by vacuum distillation; finally, the temperature is further increased to 128-132℃, and the intermediate product p-phenylenedicarboxylic acid chloride D is separated by vacuum distillation.

10. The working fluid of claim 5, wherein: The structural formula of the dialkylamine F1 described in step (2) is: The structural formula of the dialkylamine F2 is: wherein R1, R2, R3, R4 are one of furan, arene substituent, benzyl or alkane substituent.

11. The working fluid of claim 5, wherein: The alkyl, alkoxy, ester group is one or more functional groups contained in the alkyl substituent, furan, benzyl or aromatic hydrocarbon substituent.

12. The working fluid of claim 5, wherein: The organic solvent E in step (2) is selected from chlorobenzene, dichloromethane or trichloromethane, and the molar ratio of the organic solvent E to p-phenylenedicarboxylic acid chloride D is 1:1.5-100.

13. The working fluid of claim 5, wherein: The molar ratio of the dialkylamine F1, F2 to p-phenylenedicarboxylic acid chloride C in step (2) is 1:1:0.5-1.

14. The working fluid of claim 5, wherein: The amidation reaction condition in step (2) is that the reaction liquid is reacted in a condensation reflux reactor under normal pressure and at 50-120℃ for 0.5-4 hours.

15. The working fluid of claim 5, wherein: The washing in step (3) is that the reaction mixture is washed 2-4 times with hydrochloric acid, sodium carbonate solution and deionized water, and finally the reaction liquid is neutralized.

16. The working fluid of claim 5, wherein: The separation and purification mode in step (3) is vacuum distillation, adsorption separation or extraction.

17. A process for hydrogenation of hydrogen peroxide produced by the anthraquinone process, characterized by: In the process, the working liquid in claim 1 or 2 is used; in the hydrogenation reaction process, the hydrogenation reactor is in the form of fluidized bed, slurry bed or fixed bed, and the hydrogenation process condition is that the hydrogenation temperature is 25-80℃, and the pressure is 0.1-0.7 MPa. ​

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