Method for neutralizing a resorcinol reaction solution containing an acid catalyst

Abstract

This invention discloses a method for neutralizing a resorcinol reaction solution containing an acid catalyst. Specifically, an organic alcohol amine is added to the resorcinol reaction solution containing the acid catalyst to neutralize the solution. This method allows for the neutralization of the resorcinol reaction solution stream at high temperatures, produces very few byproducts, has higher neutralization efficiency compared to organic amines, results in less resorcinol loss, and produces little or no scale buildup.

Description

Technical Field

[0001] This invention relates to a neutralization method, and more particularly to a neutralization method for a resorcinol reaction solution containing an acid catalyst. Background Technology

[0002] Resorcinol is an important chemical intermediate widely used in agriculture, dyes, pharmaceuticals, rubber, and other fields. Currently, the main methods for producing resorcinol include: benzene sulfonation alkali fusion method, m-phenylenediamine method, and m-diisopropylbenzene oxidation method. Among these, the m-diisopropylbenzene oxidation method has attracted widespread attention from scholars both domestically and internationally due to its advantages of low pollution, low cost, short process, and high yield. This method involves first oxidizing m-diisopropylbenzene (DIPB) to generate the intermediate 1,3-disperoxide diisopropylbenzene (DHP), which is then decomposed under acid catalysis to produce resorcinol and acetone.

[0003] Typically, the acid catalysts used in resorcinol manufacturing processes are strong acids, usually inorganic acids such as sulfuric acid or phosphoric acid. After the decomposition reaction is complete, the acid catalyst must be neutralized to prevent resorcinol from reacting with other substances in downstream purification steps. In commercial production, processes for manufacturing resorcinol often use inorganic bases, organic amines, ion exchange resins, or combinations thereof to remove acidic substances from the crude product stream.

[0004] Patent GB1446557A uses a strong base (such as sodium hydroxide or potassium hydroxide) to neutralize the acidic catalyst. However, strong base neutralization is not always necessary because it is difficult to precisely control the pH value after the neutralization reaction between strong acid and strong base. In addition, strong base neutralization easily produces salts, which deposit on the inner surface of the heat exchanger, causing scale buildup and significantly reducing neutralization efficiency.

[0005] Ion exchange resins are highly temperature-sensitive, so the crude product stream must be cooled before contacting the resin. Cooling the crude product stream significantly increases costs because it must be reheated before subsequent purification operations. Furthermore, ion exchange resins require frequent regeneration, generating substantial amounts of water-containing waste, further increasing process costs and manpower requirements. Additionally, the pH of the crude product stream is difficult to control during ion exchange resin neutralization, affecting final product yield and releasing alkali metal salts that contribute to equipment fouling.

[0006] Patent CN113135819B uses organic amines such as n-hexylamine, n-butylamine, and propylamine as neutralizing agents, but these are also added after the crude product stream has cooled, resulting in low neutralization efficiency. Furthermore, research has found that if the neutralization efficiency is increased by raising the temperature, the resorcinol loss rate is high, and the content of insoluble precipitates after neutralization increases. It is speculated that side reactions that are detrimental to maintaining product yield have occurred and tend to generate heavy components, which can easily lead to equipment blockage or scale buildup. Summary of the Invention

[0007] To address the above technical problems, this invention proposes a neutralization method for resorcinol reaction solutions containing acid catalysts, which can avoid or improve the aforementioned neutralization problems.

[0008] It has been found that in the resorcinol production process, the neutralization of the acid catalyst can be achieved by adding an organic alcohol amine after the DHP decomposition reaction is completed. Advantageously, the method of the present invention allows for the neutralization of the resorcinol reaction stream at high temperatures; because organic alcohol amines are better dispersed in the system, their neutralization efficiency is higher than that of n-hexylamine, n-butylamine, and n-propylamine, while resulting in less resorcinol loss and minimal or no fouling.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A method for neutralizing a resorcinol reaction solution containing an acid catalyst involves adding an organic alcohol amine to the resorcinol reaction solution containing an acid catalyst to neutralize the reaction solution.

[0011] The amount of organic alcohol amine added is 1.05-1.2 times the molar amount of acid catalyst in the reaction solution.

[0012] As a preferred embodiment of the present invention, the resorcinol reaction solution containing the acid catalyst is a reaction solution obtained by decomposing 1,3-diisopropylbenzene peroxide under acid catalysis to prepare resorcinol, wherein the resorcinol content is 4.0-6.0 wt% and the acid catalyst content is 1000-2000 ppm.

[0013] As a preferred embodiment of the present invention, the acid catalyst is an acidic homogeneous catalyst having a pKa value of less than 5 in an aqueous medium, preferably in the form of an acid of at least one of carboxylates, nitrates, phosphates, phosphonates, sulfates, and sulfonates, and more preferably at least one of sulfuric acid, phosphoric acid, nitric acid, and benzenesulfonic acid.

[0014] As a preferred embodiment of the present invention, the organic alcohol amine is a compound containing at least one hydroxyl group and at least one amino group, preferably an alcohol amine with the number of carbon atoms C1-C6, and more preferably one or more of ethanolamine, diethanolamine, n-propanolamine, isopropanolamine, di-n-propanolamine, n-butanolamine, di-n-butanolamine, and aminoethylethanolamine.

[0015] As a preferred embodiment of the present invention, the temperature of the neutralization reaction is 15-80°C, preferably 60-80°C.

[0016] As a preferred embodiment of the present invention, after the neutralization reaction is completed, the product resorcinol is obtained by distillation.

[0017] In this invention, the resorcinol reaction solution containing an acid catalyst can be prepared by any known resorcinol production technology using an acid catalyst, which is known to those skilled in the art, such as the general preparation schemes disclosed in patents JP1997143112A and CN1027974C.

[0018] The structural formulas of the main organic compounds involved in the above production process are as follows:

[0019]

[0020] Specifically, after the reaction for synthesizing resorcinol is substantially complete, for example, at least 80% complete, but before the purification step, an organic alcohol amine is added to the resorcinol reaction solution. The percentage of completion can be measured by measuring the weight percentage of material consumed in the conversion to resorcinol (such as 1,3-dicumyl peroxide).

[0021] In some embodiments of the present invention, apart from organic alcohol amines, other neutralizing agents are generally not used, such as caustic alkali exchange resins, ammonia, sodium carbonate, sodium hydroxide, alkaline clay, activated carbon, anion exchange resins, etc.

[0022] In some embodiments of the present invention, amino compounds are not used in large quantities, except for organic alcohol amines.

[0023] This invention utilizes organic alcohol amines in the neutralization process of residual acid catalysts in crude resorcinol streams, resulting in higher neutralization efficiency, minimal or no fouling, less resorcinol loss, and higher yield. The use of organic alcohol amines in this invention is particularly advantageous because they can be applied at high temperatures, thus eliminating the need for cooling process streams prior to neutralization (in processes using high temperatures) and eliminating the need for subsequent reheating before purification steps. Detailed Implementation

[0024] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0025] Unless otherwise specified, the raw materials and reagents used in the following embodiments of the present invention can be purchased commercially.

[0026] The main testing instruments and operating conditions used in this invention are as follows:

[0027] (1) Metrohm 905Titrando potentiometric titrator. Standard solution: 0.1mol / L NaOH aqueous solution.

[0028] (2) High performance liquid chromatography: Shimadzu LC-20AT, operating conditions: column: Waters XSelect HSS T35wnX4.6mmX250mm, detection wavelength 233nm, mobile phase: acetonitrile / water (containing 0.1% phosphoric acid) = 35 / 65, elution mode: isocratic elution, flow rate: 1.0mL / min, column temperature 30℃, injection volume 10µL.

[0029] The main testing methods used in this invention are as follows:

[0030] (1) Acidity: Tested using a Swiss Metrohm 905Titrando potentiometric titrator.

[0031] (2) Sediment content (%): Take 100g of neutralization reaction solution and centrifuge at 3000r / min and room temperature for 10min to obtain sediment. After drying, weigh it and calculate the dry weight to the mass ratio of the neutralization reaction solution.

[0032] (3) Product loss rate (%): The loss rate was calculated by testing the resorcinol content before and after neutralization using liquid chromatography.

[0033] Product loss rate = (mass of resorcinol before neutralization (g) - mass of resorcinol after neutralization (g)) / mass of resorcinol before neutralization (g)

[0034] [Preparation Example 1]

[0035] Preparation of resorcinol reaction solution A containing an acid catalyst:

[0036] (1) Oxidation reaction stage: Take 5000g of m-diisopropylbenzene, 10g of cumene hydroperoxide, and 2500g of 2wt% alkaline solution, and add them to a 15L high-pressure reactor. Heat to 80℃. Introduce air, control the pressure at 3 barg, and continuously purge at a rate of 1200ml / min. Control the pressure inside the reactor through a back pressure valve. React for 30h, remove the reaction solution, let it stand, separate the oil and water, and detect the concentration of DHP in the oil phase: 70.26wt%, HHP concentration: 15.26wt%, and KHP concentration: 3.26wt%.

[0037] (2) Alkali extraction stage: Take the oil phase of the oxidation reaction liquid, add 3 times the mass of 6wt% sodium hydroxide solution, stir at 20℃, and after 20min the layers are separated. Hydroperoxides HHP and DHP generated in the oxidation stage exist in the alkaline phase in the form of ions.

[0038] (3) Low-temperature back-extraction stage: The alkaline phase in (2) is introduced into the low-temperature back-extraction tower, and twice the mass of methyl isobutyl ketone is added. The mixture is stirred at 20°C for 30 min for back-extraction. The HHP content in the extract is 3.13 wt%, thereby separating HHP.

[0039] (4) High-temperature back-extraction stage: The residual alkaline phase from the low-temperature raffinate in (3) is introduced into the high-temperature back-extraction tower, and twice the mass of MIBK is added. The mixture is stirred at 60°C for 30 min for back-extraction. The DHP content in the extract is 11.62 wt%. Thus, a methyl isobutyl ketone solution with 11.62 wt% DHP is obtained.

[0040] (5) Washing and Concentration Stage of DHP in Methyl Isobutyl Ketone Solution: The methyl isobutyl ketone phase from (4) was introduced into a water washing tower, and pure water of equal mass was added and stirred for 5 minutes at room temperature for washing. The washed DHP was then distilled in a vacuum distillation tower at a pressure of 40 kPa (absolute pressure) and a bottom temperature of 45°C. This yielded a methyl isobutyl ketone solution containing 21.07 wt% DHP, 0.33 wt% KHP, and 0.57 wt% HHP.

[0041] (6) Resorcinol reaction solution preparation stage: Add 100g of acetone and 0.2g of sulfuric acid to 100g of methyl isobutyl ketone solution containing 21.07wt% DHP, 0.33wt% KHP and 0.57wt% HHP. The amount added reaches the sulfuric acid concentration of 1000ppm in the system. The temperature is raised to 60℃ and the reaction is carried out for 15 minutes to obtain resorcinol reaction solution A, in which the resorcinol concentration is 5.12wt%.

[0042] [Preparation Example 2]

[0043] Preparation of resorcinol reaction solution B containing acid catalyst:

[0044] Using the methyl isobutyl ketone solution containing 21.07 wt% DHP, 0.33 wt% KHP, and 0.57 wt% HHP provided in steps (1)-(5) of Example 1 as raw material, 100 g of acetone and 0.4 g of phosphoric acid were added to 100 g of the solution, so that the phosphoric acid concentration inside the system was 2000 ppm. The temperature was raised to 60 °C and the reaction was carried out for 15 minutes to obtain resorcinol reaction solution B, in which the resorcinol concentration was 4.93 wt%.

[0045]

Example 1

[0046] Ethanolamine was added to resorcinol reaction solution A containing an acid catalyst, with the amount added being 1.05 times the molar amount of sulfuric acid in reaction solution A. A neutralization reaction was carried out at 60℃. After 2 minutes, the acidity of the reaction solution was measured to be 11.2 mg / g NaOH, indicating a high neutralization efficiency. Liquid chromatography analysis showed that the resorcinol content was 5.11 wt%, and the calculated resorcinol loss rate was 0.102%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 0.06 g.

[0047]

Example 2

[0048] Propanolamine was added to resorcinol reaction solution A containing an acid catalyst. The amount added was 1.10 times the molar amount of sulfuric acid in reaction solution A. Neutralization was carried out at 70℃. After 2 minutes, the acidity of the reaction solution was measured to be 6.6 mg / g NaOH, indicating a high neutralization efficiency. Liquid chromatography analysis showed that the resorcinol content was 5.11 wt%, and the calculated resorcinol loss rate was 0.095%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 0.01 g.

[0049]

Example 3

[0050] Diethanolamine was added to resorcinol reaction solution A containing an acid catalyst. The amount added was 1.20 times the molar amount of sulfuric acid in reaction solution A. Neutralization was carried out at 25℃. After 2 minutes, the acidity of the reaction solution was measured to be 43.5 mg / g NaOH, indicating a high neutralization efficiency. Liquid chromatography analysis showed that the resorcinol content was 5.10 wt%, and the calculated resorcinol loss rate was 0.223%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 0.23 g.

[0051]

Example 4

[0052] n-Butanolamine was added to resorcinol reaction solution B containing an acid catalyst. The amount added was 1.20 times the molar amount of sulfuric acid in reaction solution A. A neutralization reaction was carried out at 80℃. After 2 minutes, the acidity of the reaction solution was measured to be 21.5 mg / g NaOH, indicating a high neutralization efficiency. Liquid chromatography analysis showed that the resorcinol content was 5.11 wt%, and the calculated resorcinol loss rate was 0.102%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 0.02 g.

[0053]

Example 5

[0054] Isopropanolamine was added to resorcinol reaction solution B containing an acid catalyst. The amount added was 1.05 times the molar amount of phosphoric acid in reaction solution B. A neutralization reaction was carried out at 15℃. After 2 minutes, the acidity of the reaction solution was measured to be 55.6 mg / g NaOH, indicating a high neutralization efficiency. Liquid chromatography analysis showed that the resorcinol content was 4.91 wt%, and the calculated resorcinol loss rate was 0.266%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 0.24 g.

[0055]

Example 6

[0056] Di-n-propanolamine was added to resorcinol reaction solution B containing an acid catalyst. The amount added was 1.05 times the molar amount of phosphoric acid in reaction solution B. A neutralization reaction was carried out at 60℃. After 2 minutes, the acidity of the reaction solution was measured to be 18.2 mg / g NaOH, indicating a high neutralization efficiency. Liquid chromatography analysis showed that the resorcinol content was 4.91 wt%, and the calculated resorcinol loss rate was 0.098%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 0.09 g.

[0057]

Example 7

[0058] Di-n-butanolamine was added to resorcinol reaction solution B containing an acid catalyst. The amount added was 1.05 times the molar amount of phosphoric acid in reaction solution B. A neutralization reaction was carried out at 40℃. After 2 minutes, the acidity of the reaction solution was measured to be 23.9 mg / g NaOH, indicating a high neutralization efficiency. Liquid chromatography analysis showed that the resorcinol content was 4.91 wt%, and the calculated resorcinol loss rate was 0.105%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 0.08 g.

[0059] Comparative Example 1

[0060] The comparative example was carried out under essentially the same conditions as Example 3, except that the added diethanolamine was replaced with sodium hydroxide. After 2 minutes, the acidity of the reaction solution was measured to be 355.6 mg / g NaOH, indicating a low neutralization efficiency. Liquid chromatography analysis showed a resorcinol content of 4.63 wt%, with a calculated resorcinol loss rate of 9.613%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 1.86 g.

[0061] Comparative Example 2

[0062] The comparative example was carried out under essentially the same conditions as Example 3, except that the added diethanolamine was replaced with n-butylamine. After 2 minutes, the acidity of the reaction solution was measured to be 239.5 mg / g NaOH, indicating a low neutralization efficiency. Liquid chromatography analysis showed a resorcinol content of 4.85 wt%, with a calculated resorcinol loss rate of 5.106%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 1.05 g.

[0063] Comparative Example 3

[0064] This comparative example underwent a neutralization reaction under essentially the same conditions as Comparative Example 2, the only difference being that the neutralization reaction temperature was adjusted to 60℃. After the reaction, the acidity of the reaction solution was measured to be 138.8 mg / g NaOH. Liquid chromatography analysis revealed a resorcinol content of 4.58 wt%, with a calculated resorcinol loss rate of 10.384%. 100 g of the neutralized reaction solution was centrifuged and dried to obtain a precipitate weighing 2.13 g.

[0065] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A method for neutralizing a resorcinol reaction solution containing an acid catalyst, characterized in that, An organic alcohol amine was added to the resorcinol reaction solution containing an acid catalyst to neutralize the reaction solution. The amount of the organic alcohol amine added is 1.05-1.2 times the molar amount of the acid catalyst in the reaction solution; The acid-catalyst-containing resorcinol reaction solution is a reaction solution obtained by decomposing 1,3-diisopropylbenzene peroxide under acid catalysis to prepare resorcinol, wherein the resorcinol content is 4.0-6.0 wt% and the acid catalyst content is 1000-2000 ppm. The acid catalyst is at least one of sulfuric acid, phosphoric acid, nitric acid, and benzenesulfonic acid; The organic alcohol amine is one or more selected from ethanolamine, diethanolamine, n-propanolamine, isopropanolamine, di-n-propanolamine, n-butanolamine, di-n-butanolamine, and aminoethylethanolamine; The neutralization reaction is carried out at a temperature of 60-80℃.

2. The neutralization method for the resorcinol reaction solution containing an acid catalyst according to claim 1, characterized in that, After the neutralization reaction is completed, the product resorcinol is obtained by distillation.

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