Working solution for hydrogen peroxide production 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, tri-octyl phosphate and aromatic hydrocarbon, the aromatic hydrocarbon is generally C7-C 10 The solvent comprises 2-30 parts of p-phenylenediacetamide derivative A, preferably 5-20 parts, 2-20 parts of tri-octyl phosphate, preferably 5-15 parts, and 30-95 parts of aromatic hydrocarbon, preferably 60-80 parts; 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 dissolving and mass transfer capacity for hydrogen, anthraquinone and hydrogen anthraquinone, high hydrogenation efficiency, low mutual solubility with water, stable physical and chemical properties, good hydrogenation resistance and oxidation resistance of the solvent, low decomposition rate, and can significantly improve the production efficiency of the hydrogen peroxide device.

Description

Technical Field

[0001] This invention pertains to hydrogen peroxide preparation technology, specifically relating to an anthraquinone method for producing hydrogen peroxide working solution. Background Technology

[0002] Hydrogen peroxide, as one of the cleanest and most environmentally friendly green chemicals, is characterized by its strong oxidizing power, high atom utilization rate, and zero pollution to the environment. It is widely used in numerous fields, including chemical industry, paper bleaching, textile printing and dyeing, pharmaceutical synthesis, sterilization and disinfection, environmental protection, and electronics manufacturing. Especially against the backdrop of global carbon reduction and emission reduction, and my country's focus on safety, environmental protection, and industrial restructuring, the competitiveness of the hydrogen peroxide industry has significantly increased, and market demand has been growing steadily for many years.

[0003] More than 98% of hydrogen peroxide products worldwide are produced using the anthraquinone process. This process typically uses 2-alkylanthraquinone as a carrier for the H2 and O2 reaction, forming a working solution with an organic solvent. The working solution is then 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).

[0004] 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 hydroanthraquinone solvents. Anthraquinone solvents are generally aromatic hydrocarbons (AR); hydroanthraquinone solvents are the core factor affecting the performance of the working fluid, and currently, industrial applications mainly use higher fatty alcohols, organic acids, or inorganic acid esters, such as trioctyl phosphate (TOP).

[0005] Since the 1990s, my country's hydrogen peroxide industry has been using the "traditional anthraquinone process" production technology from abroad. Although domestic technology has improved slightly in recent years, the core indicator of domestic production equipment (anthraquinone hydrogenation efficiency, or hydrogen efficiency for short) is only 6.5-7.5 g / L, far lower than the 11.5-12.5 g / L hydrogen efficiency levels of Europe, the United States, and Japan. This means that the amount of hydrogen peroxide produced per liter of working fluid in my country is only 57-60% of that in developed countries. The core technical problem lies in the lack of high-performance "blood" (hydrogen) in my country. The existing domestic working fluid system has insufficient mass transfer for dissolving raw material hydrogen, anthraquinone, and especially hydrogenation products, which greatly limits the reaction conversion rate and hydrogenation efficiency. This not only leads to low single-pass yield of hydrogen peroxide, low production efficiency, high raw material consumption, and large amounts of waste discharge, but also results in low concentration of crude hydrogen peroxide. To obtain high-concentration, high-quality products to meet industry demand, the subsequent distillation and purification processes of crude hydrogen peroxide pose a great threat and challenge to the safe production of the hydrogen peroxide industry.

[0006] Based on the AR / TOP binary working solution, CN1552618A discloses an aromatic hydrocarbon + trioctyl phosphate + methyl cyclohexyl acetate (AR / TOP / MCHA) ternary working solution. Compared with the traditional AR / TOP working solution, the AR / TOP / MCHA system can increase the solubility of 2-ethylanthraquinone by 30 g / L, and the hydrogenation efficiency of the working solution can be increased to 9-9.5 g / L. CN1583546A discloses an aromatic hydrocarbon + trioctyl phosphate + tetrabutylurea (AR / TOP / TBU) ternary working solution, 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 an aromatic hydrocarbon + trioctyl phosphate + N-phenyl-N-ethylbenzamide ternary working solution, which increases the solubility of hydroanthraquinone by nearly 10-20% compared with the AR / TOP working solution, and the hydrogenation efficiency is improved. The concentration can reach 11-12 g / 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, high carbon residue in the hydrogen peroxide product, and poor application effect; 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. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention proposes an anthraquinone process for producing hydrogen peroxide working fluid. This working fluid exhibits good solubility and mass transfer for hydrogen, 2-alkyl groups, and especially hydrogen anthraquinone, thus inhibiting the degradation rate of anthraquinone in the working fluid. It also boasts high hydrogenation efficiency, good resistance to hydrogenation and oxidation, low solvent decomposition rate, and low residual carbon content in the hydrogen peroxide product, demonstrating promising prospects for industrial applications.

[0008] The working fluid of this invention includes a solvent and a working carrier. The solvent includes terephthalamide derivative A, trioctyl phosphate, and aromatic hydrocarbons, wherein the structural formula of terephthalamide derivative A is: R1, R2, R3, and R4 are alkane substituents or benzyl substituents with 1 to 8 carbon atoms, respectively. These alkane substituents or benzyl substituents may also contain alkoxy or 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 solution. The total number of carbon atoms in R1 to R4 is generally not higher than 20. The aromatic hydrocarbons are generally C7 to C8.10 Aromatic hydrocarbons; the solvent, by volume, comprises 2-30 parts of terephthalamide derivative A, preferably 5-20 parts, 2-20 parts of trioctyl phosphate, preferably 5-15 parts, and 30-95 parts of aromatic hydrocarbons, preferably 60-80 parts.

[0009] 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.

[0010] The method for synthesizing terephthalamide derivative A of the present invention includes the following steps:

[0011] (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 atom to generate dicarboxylic acid acyl chloride D. After the reaction is completed, 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 amount of triethylamine and dialkylamine F1 or F2 or a mixture of F1 and F2. Under certain temperature conditions, carry out amidation reaction to obtain crude terephthalic acid acyl chloride derivative A. (3) After the reaction solution in step (2) is cooled to room temperature, filter and wash until neutral, let stand to separate the lower organic phase, and then separate and purify to finally obtain the target product terephthalic acid acyl chloride derivative A.

[0012] In the method of this invention, the dehydration reaction formula in step (1) is as follows (taking phosphate acyl chloride PCl5 as an example):

[0013]

[0014] In the method of the present invention, 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 to terephthalic acid is 1:1.5 to 75, preferably 2 to 30.

[0015] 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.

[0016] 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 a negative pressure environment (-0.1 to -0.03MPa). Finally, the temperature is further increased to a temperature range of 128-132℃ and the intermediate product p-phenylenedicarboxylic acid acyl chloride D is separated by vacuum distillation under a negative pressure environment (-0.1 to -0.03MPa).

[0017] In the method of the present invention, the reaction formula in step (2) is as follows:

[0018]

[0019] In the method of the present invention, the dialkylamine mentioned in step (2) is a dialkylamine F1 (NHR1R2) and / or F2 (NHR3R4), wherein R1, R2, R3, and R4 are one of furan, aromatic substituent, benzyl or alkane substituent, and the furan, aromatic substituent, benzyl or alkane substituent may also contain one or more functional groups of alkyl, alkoxy, and ester groups.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] In the method of this invention, the separation and purification method described in step (3) is vacuum distillation, adsorption separation, or extraction. For example, under vacuum distillation conditions of -0.1 to -0.03 MPa, the fraction taken at 201 to 206 °C is the final target product, terephthalamide derivative A.

[0025] 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%.

[0026] 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.

[0027] Compared with the prior art, the working solution of the present invention has the following advantages: (1) It has good solubility and mass transfer performance for hydrogen reactants. The better solubility can increase the accessibility of reactants and catalysts and inhibit the degradation rate of anthraquinone; (2) It has good solubility for hydrogen anthraquinone. Under the same working conditions, the solubility of hydrogen anthraquinone in the working solution of the present invention is nearly 40% higher than that of existing industrial working solutions, reaching more than 95 g / L, which can significantly increase the effective anthraquinone concentration in the working solution and improve the hydrogenation conversion rate of anthraquinone; (3) It has high solubility for anthraquinone: the composite solution at room temperature has good solubility for hydrogen anthraquinone. The solubility of the agent for 2-ethylanthraquinone is above 175 g / L, which is more than 20% higher than that of the existing industrial working solution, thus improving the hydrogenation efficiency of the working solution; (4) High hydrogenation efficiency: Under the above hydrogenation catalyst and process conditions, the hydrogenation efficiency of the 2-ethylanthraquinone working solution can reach more than 12.9 g / L, and the hydrogenation efficiency of the 2-pentylanthraquinone working solution can reach more than 15 g / L; (4) The working solution has good antioxidant properties, low solvent decomposition rate, and low residual carbon in hydrogen peroxide products, which can improve the production capacity and utilization efficiency of the anthraquinone hydrogen peroxide plant. Detailed Implementation

[0028] 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:

[0029] 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 150~180m² 2 / g, with a Pd content of 0.25wt% to 0.35wt%.

[0030] 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:

[0031]

[0032]

[0033] 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.] 10Aromatic hydrocarbons, trioctyl phosphate, and terephthalamide derivative A were prepared into 200 mL test solvents at different volume fractions and added into 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.

[0034] 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.

[0035] Hydrogen dissolution mass transfer analysis method: The "dissolution saturation method" is used to determine the gas-liquid phase equilibrium data of the working solution solvent system and hydrogen. The analytical apparatus mainly consists of three parts: a 500mL stainless steel mechanically stirred tank, a vacuum system, and a pressure and temperature control system. Before the measurement, 300mL of the solvent to be tested is placed in the reaction vessel for vacuum degassing. The airtightness of the measurement system is checked by N2. If there is no pressure change in the system within 1 hour, it indicates that the airtightness of the measurement system is good. The working solution to be tested is heated to the predetermined temperature, and H2 is rapidly introduced to replace the N2 in the device three times. Then, stirring is started in the tank, and the change of hydrogen partial pressure in the system with the measurement time is recorded simultaneously. In the constant-volume closed reactor, H2 is dissolved and absorbed by the bulk liquid phase of the working solution, resulting in the hydrogen partial pressure in the reactor being a function of physical dissolution time. The pressure gradually decreases with the contact time. The calculation process of hydrogen solubility and mass transfer coefficient (ka) in different solvent systems is as follows:

[0036]

[0037] Where N L Let R be the mass transfer rate of H2 in the solvent system, P be the gas constant, and T be the pressure and temperature under the experimental conditions, respectively. G To test the gas phase volume within the system, integrating equation 3 yields...

[0038]

[0039] The above mass balance equation for H2 in the working fluid is compared with Henry's equation P. * =H·C * The association can be obtained

[0040]

[0041] Let α be the notation With initial state P = P0, t = 0, and mass transfer P = P i Integrating 5 with respect to the boundary condition t=t, the volume transfer coefficient of H2 in the bulk liquid phase of the working fluid can be calculated according to Equation 6.

[0042]

[0043] 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.

[0044] Example 1

[0045] Taking the synthesis process of N,N,N',N'-tetrabutylterephthalamide as an example:

[0046]

[0047] 116g of 1,4-terephthalic acid, 150mL of dichloromethane, and 250g of PCl5 were added to a 500mL reactor in a single batch. The system temperature was raised to 100℃, and the reactants were fully dissolved under thorough stirring. After maintaining the system temperature for 2 hours, the reaction was stopped, and the system was allowed to cool naturally to 40-50℃. 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 carried out under negative pressure (-0.1 to -0.03 MPa) and at 75-78℃ to separate dichloromethane and PCl5. Finally, the system temperature was further increased to 128-132℃ to obtain the fraction containing terephthalic acid chloride within this temperature range. 258.5g of dibutylamine was added to a 500mL reactor in a single batch. 150 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 at atmospheric 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%.

[0048] 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.

[0049] Example 2

[0050] Taking the synthesis process of N,N-benzyl-N',N'-diethylterephthalic acid amide as an example:

[0051]

[0052] In a 500 mL reactor, 58 g of 1,4-terephthalic acid, 100 mL of dichloromethane, and 125 g of PCl5 were added all at once. The system temperature was raised to 100 °C, and the reactants were fully dissolved under thorough 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 as phenylacetyl chloride. In another 500 mL reactor, 45 g of diethylamine, 120 g of dibenzylamine, and 200 mL of triethylamine were added, followed by the addition of phenylacetyl chloride all at once. The mixture was placed in a reaction vessel and stirred thoroughly until homogeneous. The reaction was then carried out under normal pressure, 100°C, and reflux conditions for 2 hours. After the reaction, the resulting reaction solution was washed four times with 22.5 wt.% hydrochloric acid, 30 wt.% sodium carbonate aqueous solution, and pure water to ensure neutrality. 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-benzyl-N',N'-diethylterephthaloyl, with a yield of 91.9%.

[0053] 1H NMR (500MHz, CDCl3) δ=1.12~1.17(m, 6H), 1.78~1.86(m, 2H), 2.32~2.40(m, 4H), 3.30~3.36(m, 4H), 4.43~4.47(m, 4H), 7.23~7.33(m, 10H); MS[M+H] + 362.3.

[0054] Example 3

[0055] An anthraquinone process for producing hydrogen peroxide working solution, comprising C7-C64... 10 Aromatic hydrocarbons, trioctyl phosphate, and N,N,N',N'-tetraethylterephthalamide were prepared by the method of Example 1. The working solution used 2-ethylanthraquinone as the anthraquinone carrier, and was prepared as a 2-ethylanthraquinone working solution with a volume ratio of aromatic hydrocarbons:trioctyl phosphate:N,N,N',N'-tetraethylterephthalamide of 75:15:10. Experimental results show that: at 25℃, the solubility of 2-ethylanthraquinone in the working solution solvent system is 179.8 g / L; at 50–55℃ and 0.25–0.28 MPa, the solubility of 2-ethylhydroanthraquinone is 111.4 g / L; the hydrogenation efficiency of the working solution with a 2-ethylanthraquinone mass concentration of 175 g / L is 12.9 g / L; the solubility of H2 in the working solution system is 1.39 mmol / L; the oxidative decomposition rate of the composite working solution is 14.9%; and the mass transfer factor of H2 is 0.155 s⁻¹. -1 The organic residual carbon in the hydrogen peroxide product was 122.3 ppm, and the separation and demulsification time of the working solution and pure water was 37 s.

[0056] Example 4

[0057] An anthraquinone process for producing hydrogen peroxide working solution comprises aromatic hydrocarbons, trioctyl phosphate, and N,N,N',N'-tetraethylterephthalamide, wherein the N,N,N',N'-tetraethylterephthalamide is prepared by the method of Example 1. The working solution uses 2-pentylanthraquinone as the anthraquinone carrier, and the ratio of aromatic hydrocarbons:trioctyl phosphate:N,N,N',N'-tetraethylterephthalamide is 75:15:10 by volume to prepare the 2-pentylanthraquinone working solution. Experimental results show that: at 25℃, the solubility of 2-pentylanthraquinone in the working solution solvent system is 537.5 g / L; at 50–55℃ and 0.25–0.28 MPa, the solubility of 2-pentylhydroanthraquinone is 133.4 g / L; the hydrogenation efficiency of the working solution with a 2-pentylanthraquinone mass concentration of 300 g / L is 17.1 g / L; the solubility of H2 in the working solution system is 1.40 mmol / L; the oxidative decomposition rate of the composite working solution is 14.9%; and the mass transfer factor of H2 is 0.153 s⁻¹. -1 The organic residual carbon in the hydrogen peroxide product was 118.9 ppm, and the separation and demulsification time between the working solution and pure water was 37.5 s.

[0058] Example 5

[0059] An anthraquinone process for producing hydrogen peroxide working fluid comprises an aromatic hydrocarbon, trioctyl phosphate, and N,N,N',N'-tetrabutylterephthalamide. The composite working fluid uses 2-ethylanthraquinone as the anthraquinone carrier, and the ternary solvent, by volume, comprises C9-C9... 10A 2-ethylanthraquinone working solution was prepared by mixing aromatic hydrocarbons, trioctyl phosphate, and N,N,N',N'-tetrabutylterephthalamide in a ratio of 75:12.5:12.5. Experimental results showed that the solubility of 2-ethylanthraquinone in this working solution solvent system was 186.9 g / L at 25℃, and 95.7 g / L at 50–55℃ and 0.25–0.28 MPa. The hydrogenation efficiency of the working solution with a 2-ethylanthraquinone mass concentration of 180 g / L was 13.1 g / L. The solubility of H2 in this working solution system was 1.33 mmol / L. The oxidative decomposition rate of the composite working solution was 14.5%, and the mass transfer factor of H2 was 0.151 s⁻¹. -1 The organic residual carbon in the hydrogen peroxide product was 119.5 ppm.

[0060] Example 6

[0061] An anthraquinone process for producing hydrogen peroxide working solution comprises an aromatic hydrocarbon, trioctyl phosphate, and N,N'-benzyl-N,N'-diethylterephthalamide. The composite working solution uses 2-pentylanthraquinone as the anthraquinone carrier, and the ternary solvent, by volume, comprises C9–C9 compounds. 10 A 2-pentylanthraquinone working solution was prepared by mixing aromatic hydrocarbons, trioctyl phosphate, and N,N'-benzyl-N,N'-diethylterephthalamide in a ratio of 60:20:20. Experimental results showed that the solubility of 2-pentylanthraquinone in this working solution solvent system was 511.3 g / L at 25℃, and 153.1 g / L at 50–55℃ and 0.25–0.28 MPa. The hydrogenation efficiency of the working solution with a 2-pentylanthraquinone concentration of 300 g / L was 18.4 g / L. The solubility of H2 in this working solution system was 1.64 mmol / L. The oxidative decomposition rate of the composite working solution was 18.5%, and the mass transfer factor of H2 was 0.181 s⁻¹. -1 The organic residual carbon in the hydrogen peroxide product was 167.7 ppm.

[0062] Comparative Example 1

[0063] Measured by volume fraction, in C9~C 10 A mixture of aromatic hydrocarbons and trioctyl phosphate (75 / 25) was used as the solvent, and 2-ethylanthraquinone was used as the anthraquinone carrier to prepare the 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 C9–C9. 10The solubility of H2 in the aromatic hydrocarbon / trioctyl phosphate working solution system is 123–130 g / L. At 50–55 °C and 0.25–0.30 MPa, the solubility of 2-ethylanthraquinone is 68.5–69 g / L. The hydrogenation efficiency of the working solution with a 2-ethylanthraquinone concentration of 125 g / L is 6.5–7.3 g / L. The solubility of H2 in this working solution system is 1.12 mmol / L. The degradation rate of the working solution is 29.8%, and the mass transfer factor of H2 is 0.125 s⁻¹. -1 The organic residual carbon in the hydrogen peroxide product was 355 ppm, and the separation and demulsification time between the working solution and pure water was 31 s.

[0064] Comparative Example 2

[0065] 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 concentration of 154 g / L exhibited a solubility of 51.5–53.1 g / L for hydrogen anthraquinone, a hydrogenation efficiency of 7.4–7.8 g / L, a H2 solubility of 1.27 mmol / L, a working solution degradation rate of 33.1%, and a H2 mass transfer factor of 0.131 s⁻¹. -1 The residual organic carbon in the hydrogen peroxide product was 851 ppm, and the separation and demulsification time between the working solution and pure water was 33 s.

[0066] Comparative Example 3

[0067] 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 this working solution system was 155–163 g / L at 25℃ and atmospheric pressure; the solubility of 2-ethylhydroanthraquinone was 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 degradation rate of the working solution was 22.6%; the solubility of H2 in this working solution system was 1.30 mmol / L; and the mass transfer factor of H2 was 0.135 s⁻¹. -1 The residual organic carbon in the hydrogen peroxide product was 1031 ppm, the solvent oxidation decomposition rate was 12.9%, and the separation and demulsification time of the working solution and pure water was 72 s.

[0068] Comparative Example 4

[0069] 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. Experimental results showed that the solubility of 2-ethylanthraquinone in the working solution system was 165 g / L at 25℃ and normal pressure; the solubility of 2-ethylhydroanthraquinone was 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 was 10.33 g / L; the organic residual carbon in the hydrogen peroxide product was 129.6 ppm; the oxidative decomposition rate of the solvent during 120 hours of oxidation was 17.3%; and the separation and demulsification time between the working solution and pure water was 41 s.

[0070] Comparative Example 5

[0071] 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, characterized in that: The solvent comprises p-xylylene diamide derivative A, trioctyl phosphate and aromatic hydrocarbon, wherein the structural formula of p-xylylene diamide derivative A is: wherein R1, R2, R3, R4 are each an alkane substituent of 1 to 8 carbon atoms or a benzyl substituent, the total number of carbon atoms not being more than 20; the aromatic hydrocarbon is a C7 to C 10 aromatic hydrocarbon; the solvent is 2 to 30 parts by volume of the p-xylylene diamide derivative A, 2 to 20 parts of trioctyl phosphate, and 30 to 95 parts of the aromatic hydrocarbon; the working carrier is one or more of anthraquinone and its derivatives.

2. The working fluid of claim 1, wherein: The alkane substituent or benzyl substituent further comprises alkoxy or ester group.

3. The working fluid of claim 1, wherein: The working carrier is 2-alkyl anthraquinone.

4. The working fluid of claim 1, wherein: The synthesis method of p-xylylene diamide derivative A comprises the following steps: (1) p-xylylene dicarboxylic acid is dissolved in organic solvent B, and the hydroxyl functional group of p-xylylene dicarboxylic acid is replaced by chlorine atom under the action of acyl chloride C to generate dicarboxylic acid chloride D, after the reaction is completed, the product is subjected to vacuum distillation to separate p-xylylene dicarboxylic acid chloride D; (2) p-xylylene dicarboxylic acid chloride D obtained in step (1) is dissolved in organic solvent E, and appropriate amount of triethylamine and dialkylamine are added, and amidation reaction is carried out under certain temperature condition to obtain p-xylylene diamide derivative A crude product; (3) after the reaction liquid in step (2) is cooled to room temperature, filtration, washing, and standing, the lower organic phase is separated, and the target product p-xylylene diamide derivative A is finally obtained after separation and purification.

5. The working fluid of claim 4, wherein: In the synthesis method of p-xylylene diamide derivative A, 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 to p-xylylene dicarboxylic acid is 1:1.5-75.

6. The working fluid of claim 4, wherein: In the synthesis method of p-xylylene diamide derivative A, the acyl chloride C in step (1) is one or more of phosphorus oxychloride PCl5, phosphorous oxychloride PC13 and sulfurous acid chloride SOCl2, and the molar ratio of the acyl chloride C to p-xylylene dicarboxylic acid is 1:1-20.

7. The working fluid of claim 4, wherein: In the synthesis method of p-xylylene diamide derivative A, the reaction condition in step (1) is normal pressure, 100-120℃ for 2-4 hours; after the reaction is completed, the reaction material is 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 increased to 128-132℃, and the intermediate product p-xylylene dicarboxylic acid chloride D is separated by vacuum distillation.

8. The working fluid of claim 4, wherein: In the synthesis method of p-xylylene diamide derivative A, the dialkylamine is dialkylamine F1 (NHR1R2) and / or dialkylamine F2 (NHR3R4); wherein R1, R2, R3 and R4 are one of furan, aromatic hydrocarbon substituent, benzyl or alkane substituent.

9. The working fluid of claim 8, wherein: The furan, aromatic hydrocarbon substituent, benzyl or alkane substituent further comprises one or more functional groups of alkyl, alkoxy or ester group.

10. The working fluid of claim 4, 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-xylylene dicarboxylic acid chloride D is 1:1.5-100.

11. The working fluid of claim 8, wherein: The molar ratio of dialkylamine F1, F2 to p-xylylene dicarboxylic acid chloride D in step (2) is 1:1:0.5-1.

12. The working fluid of claim 4, wherein: The reaction condition in step (2) is 50-120℃ under normal pressure, and the reaction liquid is reacted in a condensation reflux reactor for 0.5-4 hours to obtain p-xylylene diamide derivative A crude product mixture.

13. Use of the working solution according to any one of claims 1 to 12 in the production of hydrogen peroxide by the anthraquinone process.

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