Method for removing anthraquinone substances from industrial hydrogen peroxide

Abstract

The application provides a method for removing anthraquinone substances in industrial hydrogen peroxide, wherein the main organic substance in industrial hydrogen peroxide is anthraquinone, anthraquinone is weakly alkaline in hydrogen peroxide, and can be regarded as a combination of anthraquinone cation and hydroxyl radical, and the anthraquinone cation can be adsorbed and removed by a cation exchange resin. According to the above principle, the anthraquinone substances in industrial hydrogen peroxide are removed by using two-stage cation exchange, sequentially passing through a first-stage and a second-stage anti-oxidation strong acid type cation exchange resin exchange column, and low organic carbon content industrial hydrogen peroxide is obtained. The first-stage cation exchange plays a main role in the removal of the anthraquinone substances, and the second-stage ensures the stability of the removal of the anthraquinone substances. Through comprehensive comparison, the comprehensive cost of the cation exchange resin used in the application is only less than one third of the current organic adsorption resin, and the removal effect is better, and the industrialization cost is very low.

Description

Technical Field

[0001] This invention belongs to the field of chemical technology, specifically relating to the technology of removing organic impurities from industrial hydrogen peroxide, and more specifically to a method for removing anthraquinone substances from industrial hydrogen peroxide. Background Technology

[0002] Industrial-grade hydrogen peroxide introduces a large amount of organic matter during production, resulting in excessively high total organic carbon content. This includes raw materials (anthraquinone), organic solvents (trioctyl phosphate, heavy aromatics, tetrabutylurea), and their decomposition products, primarily anthraquinone compounds.

[0003] Currently, the main methods for removing anthraquinones from industrial hydrogen peroxide are: first, removal during the production process, such as coalescing separators, extraction, or distillation; and second, removal from the finished product by adsorption using adsorption resins.

[0004] Coalescing devices can only perform preliminary separation of large amounts of organic matter in hydrogen peroxide, primarily targeting insoluble organic matter for oil-water separation. For soluble organic matter, extraction is generally used, involving the extraction of C9 or C10 aromatics and industrial hydrogen peroxide at a 1:4 ratio. Distillation of hydrogen peroxide is dangerous; high temperatures can accelerate its decomposition and cause an explosion, so it is generally not used in production. Low-pressure distillation is ineffective at removing anthraquinones, as their content is relatively low and difficult to separate through distillation.

[0005] Anthraquinones in the finished product are generally removed industrially using organic adsorption resins. For example, Chinese invention patent CN109160491A discloses a method for purifying hydrogen peroxide. Hydrogen peroxide with an organic carbon content of less than 1500 ppm is passed into an adsorption resin column, where the organic carbon is adsorbed by the resin, thus purifying the hydrogen peroxide. Before use, the adsorption resin is modified as follows: first, it is soaked in C1-C4 n-alcohols or iso-alcohols at 50℃~140℃ for 8h~24h; then, it is treated in three stages with different high-pressure and high-temperature inert gases or nitrogen, with a treatment time of at least 8~24h; finally, it is washed and dried.

[0006] Commonly used adsorption resins include high molecular weight polymer resins such as polystyrene resin and polyacrylate resin, which are resin adsorbents with porous three-dimensional structures. However, when using adsorption resins for organic carbon adsorption, the organic matter is adsorbed as a whole, leading to difficulties in elution. The larger the molecular weight of the organic matter, the greater the impact on the resin capacity. In addition, the resin itself is expensive and the pretreatment is complicated, resulting in high usage costs.

[0007] When using adsorption resin to remove industrial hydrogen peroxide, there are obvious disadvantages: (1) The adsorption capacity of adsorption resin is limited. Generally, after treating 50 to 200 times the volume of industrial hydrogen peroxide, the adsorption becomes saturated or the adsorption effect deteriorates. In industry, in order to ensure that the finished product meets the organic carbon requirements, three-stage or four-stage adsorption is generally adopted (using three or four sets of adsorption resins in series). (2) The adsorption effect is unstable: When new resin or regenerated resin is first used for adsorption, the adsorption effect is good, but after that, the adsorption effect is unstable, and the organic matter adsorbed by the organic resin is easily washed away. (3) Frequent regeneration: The first and second stage adsorption resins are very easy to be saturated. On average, they need to be regenerated once every 0.5 to 3 days. During regeneration, not only a large amount of regeneration liquid (methanol or ethanol) is needed, but also a large amount of ultrapure water is needed for cleaning and a relatively large amount of manpower is required. At the same time, the regeneration process will also lead to discontinuous operation, and the material, waste, labor and time costs are relatively high. (4) The lower limit of resin adsorption is high and cannot meet the high requirements of food-grade, medical-grade and electronic-grade organic carbon. Summary of the Invention

[0008] This invention addresses the aforementioned technical problems by employing a low-cost and simple method to effectively remove anthraquinone organic compounds dissolved in industrial-grade hydrogen peroxide, achieving the requirements for medical-grade and food-grade hydrogen peroxide. The finished product is also suitable for the preliminary treatment of electronic-grade hydrogen peroxide.

[0009] The processing method of this invention is based on the following principle:

[0010] The main organic compounds in industrial-grade hydrogen peroxide are anthraquinones. In the anthraquinone core structure, the carbonyl oxygen atom has a lone pair of electrons and its electronegativity is greater than that of carbon. The bonding electrons are biased towards oxygen, so the electron cloud density of oxygen is high. It can accept protons in the hydrogen peroxide solution and form a resonance structure. Therefore, anthraquinones are weakly alkaline in hydrogen peroxide and can be regarded as a cation, which can be adsorbed and removed by cation exchange resin.

[0011]

[0012] Based on the above principle, this invention uses a two-stage cation exchange process to remove anthraquinones from industrial hydrogen peroxide. The hydrogen peroxide is passed sequentially through primary and secondary antioxidant strong acid cation exchange resin columns to obtain industrial hydrogen peroxide with low organic carbon content. The primary cation exchange stage plays a major role in the removal of anthraquinones; the secondary stage ensures the stability of the anthraquinone removal process.

[0013] In practice, industrial hydrogen peroxide with a hydrogen peroxide content of 27.5% to 60% and an organic carbon content of 50 to 1000 ppm is passed sequentially through primary and secondary antioxidant strong acid cation exchange resin columns at a temperature of 0 to 30°C and a flow rate of 3 to 15 times the resin volume per hour (preferably 5 to 10 times the resin volume per hour) to obtain industrial hydrogen peroxide with low organic carbon content.

[0014] Once the first-stage cation exchange resin is saturated, it is regenerated using 5%–6% hydrochloric acid, followed by rinsing with 10 times the resin volume of ultrapure water. The second-stage cation exchange resin can be used for an extended period.

[0015] The cation exchange resin used in this invention is a macroporous strong acid type cation exchange resin, such as a cation exchange resin with a sulfonic acid structure or a hydrogen type cation exchange resin.

[0016] In industrial-grade hydrogen peroxide, when the metal ion content is low (below 1 ppm), cation exchange resins can adsorb a large amount of anthraquinones. Regarding adsorption capacity, the adsorption capacity of organic adsorption resins is determined based on the molecular weight of the organic matter, while that of cation exchange resins is determined based on the molar number of cations. Therefore, cation exchange resins remove far more anthraquinones than organic adsorption resins.

[0017] Compared with the prior art, the technical effects of the present invention are as follows:

[0018] In terms of principle: This invention abandons the traditional approach of treating anthraquinones as carbon-based organic compounds, and instead considers their acid-base state in industrial hydrogen peroxide. Based on the fact that anthraquinones are weakly alkaline in hydrogen peroxide, an innovative solution of adsorption and removal using cation exchange resin was obtained.

[0019] Regarding industrial application costs: First, compared to currently used organic carbon adsorption resins, the price of antioxidant strong acid cation exchange resins is lower than that of antioxidant organic adsorption resins; second, the cation exchange resin of this invention removes anthraquinone organic carbon at a capacity approximately 3 to 5 times that of organic adsorption resins; third, the cation exchange resin regeneration uses 5 to 8% industrial-grade hydrochloric acid, resulting in very low costs; fourth, the regeneration cycle of the macroporous strong acid cation exchange resin used in this invention is approximately 3 to 5 times that of organic adsorption resins, and its effective total service life is greater than 2000 times (calculated by resin volume, including the service life after regeneration). In summary, the overall cost of using cation exchange resins in this invention is less than one-third of that of current organic adsorption resins, while achieving better removal effects and very low industrialization costs.

[0020] Regarding removal efficiency and regeneration: Currently, the total organic carbon in crude industrial-grade hydrogen peroxide typically ranges from 100 to 1000 ppm, primarily consisting of anthraquinones. After passing through multi-stage organic adsorption resins, the total organic carbon can only be reduced to 70 to 200 ppm, and the adsorption capacity is very limited. After the first and second stages of organic adsorption resins have treated approximately 50 to 200 times the resin volume, the adsorption resins reach saturation and can no longer adsorb organic matter, requiring regeneration. The regeneration frequency is very high, approximately every 0.5 to 3 working days.

[0021] Through experiments, this invention can reduce the organic carbon content in 35% hydrogen peroxide with a total organic carbon content of approximately 200 ppm to 50-70 ppm (mainly anthraquinones are removed). The total amount of industrial-grade hydrogen peroxide treated in a single batch can reach 800-1200 times the resin volume. It removes a large amount of organic carbon, is highly efficient, and has a long effective working time and regeneration cycle of the resin.

[0022] In terms of technical operation and environmental friendliness: Cation exchange technology is very mature and easy to operate. Because cation exchange resins remove far more anthraquinones than organic adsorption resins (approximately 3-5 times), the regeneration cycle is longer, and the labor and time costs required for regeneration are lower. The amount of wastewater discharged during regeneration is also far lower than that discharged during the regeneration of organic adsorption resins. Furthermore, this invention uses only 5%-8% industrial-grade hydrochloric acid for regeneration, thus avoiding the introduction of organic pollution. Attached Figure Description

[0023] Figure 1 This invention provides a method flow for removing anthraquinone substances from industrial hydrogen peroxide. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments and experimental examples. These should not be construed as limiting the present invention. In addition, the embodiments do not include a detailed description of conventional methods.

[0025] Example 1

[0026] 1. Experimental materials

[0027] The resin used is a macroporous strong acid cation exchange resin (ZGC151DQH styrene macroporous strong acid cation exchange resin, produced by Ningbo Zhengguang Resin Co., Ltd.), with a resin volume of approximately 1L.

[0028] 2. Experimental Methods

[0029] 1L of resin is packed into the exchange column, and then industrial-grade hydrogen peroxide is passed through the exchange column from bottom to top. The hydrogen peroxide temperature is 0–30°C, and the flow rate is approximately 5–6 L / h (5–6 times the resin volume per hour).

[0030] In this embodiment, industrial-grade hydrogen peroxide from different batches with a hydrogen peroxide content of 35%, an organic carbon content of approximately 200 ppm, and a metal ion content of less than 10 ppm was selected as raw material for testing. Shimadzu TOC-L was used for detection. Specific processing results are shown in Table 1.

[0031] Table 1 Summary of Organic Carbon Concentration of Industrial Grade Hydrogen Peroxide at Different Treatment Capacities (Level 1 and Level 2)

[0032]

[0033]

[0034] Based on the above results, industrial hydrogen peroxide with an organic carbon content of 35% and a carbon content of 200 ppm can be treated with a primary cation exchange resin. After effectively treating 800 times the volume of the resin, the organic carbon concentration can be reduced to between 60 and 110 ppm. After further treatment with a secondary cation exchange resin, the concentration can be stably maintained at 60 to 90 ppm, less than 100 ppm.

[0035] Different flow rates have a significant impact on the removal of organic carbon. Slower flow rates result in better ion exchange, but lower throughput per unit time; faster flow rates result in poorer ion exchange but higher throughput. Based on experimental results, it can be deduced that organic carbon removal is more effective and stable when the flow rate is below 8 times the resin volume per hour; above 8 times the resin volume, the removal effect deteriorates and becomes unstable. The flow rate should be determined based on actual needs (the target organic carbon removal and production volume).

[0036] Through the above process, the organic carbon content of industrial hydrogen peroxide is effectively reduced, meeting the synthesis requirements of some processes with high organic carbon requirements, such as the synthesis of caprolactam.

[0037] In terms of processing capacity, after 1L of resin treats approximately 800L of hydrogen peroxide, the removal efficiency of total organic carbon decreases, but it can still be used until it reaches complete saturation at approximately 1200 times its volume. Generally, hydrochloric acid is used for regeneration after the removal effect significantly deteriorates. During regeneration, industrial hydrochloric acid with a content of 5%–8% (6 times the resin volume) is used, at a flow rate of 0.5–2 times the resin volume per hour through the resin-packed exchange column at 0–30°C. For better regeneration, two times the resin volume of hydrochloric acid can be used first, flowing from bottom to top through the exchange column; then two times the resin volume of hydrochloric acid can be used, flowing from top to bottom; and finally, two times the resin volume of hydrochloric acid can be used, flowing from bottom to top through the exchange column.

[0038] After all the hydrochloric acid has passed through the exchange column, the residual hydrochloric acid in the exchange column is emptied. Then, ultrapure water (reverse osmosis water) with 5 times the resin volume is passed through the exchange column containing the resin from bottom to top for cleaning. Then, ultrapure water with 5 times the resin volume is passed through the exchange column from top to bottom for backwashing. After cleaning, the pH value of the effluent is about 7, which is neutral.

[0039] The resin can be regenerated and reused multiple times, with a single service life (the volume of industrial hydrogen peroxide treated) of approximately 1200 times the resin volume; the total effective service life is over 4000 times the resin volume. The overall cost is very low.

[0040] Comparative Example 1

[0041] 1. Experimental Materials

[0042] The organic adsorption resin is a polystyrene-based organic polymer (SD300 organic adsorption resin produced by Ningbo Zhengguang Resin Co., Ltd.), with a resin volume of approximately 1L.

[0043] 2. Experimental Methods

[0044] 1L of organic adsorption resin was packed into an exchange column, and then industrial-grade hydrogen peroxide was passed through the exchange column from bottom to top. The temperature of the hydrogen peroxide was 0-30℃, and the flow rate was about 5-6L / h (5-6 times the resin volume per hour).

[0045] Industrial-grade hydrogen peroxide from different batches, with a hydrogen peroxide content of 35%, an organic carbon content of approximately 200 ppm, and a metal ion content of less than 10 ppm, was selected as raw material for the experiment (using the same raw material). Shimadzu TOC-L was used for analysis. Industrially, three- or four-stage adsorption is generally used; this experiment only used data from the first-stage organic adsorption for comparison. Specific results are shown in Table 2.

[0046] Table 2 shows the organic carbon removal efficiency when using organic adsorption resin to treat industrial-grade hydrogen peroxide raw materials.

[0047] project Organic carbon (ppm) Industrial-grade hydrogen peroxide raw material 1 203.1 Industrial-grade hydrogen peroxide raw material 2 195.9 15L Primary Organic Adsorption 96.14 Primary organic adsorption 25L 71.33 40L of primary organic adsorption 130 50L primary organic adsorption 146.2 Primary organic adsorption 65L 148.7 Primary organic adsorption 75L 150.9 90L primary organic adsorption 159.1 100L Primary Organic Adsorption 168 Primary organic adsorption 115L 168.4 Primary organic adsorption 125L 180.3 140L primary organic adsorption 180.9 150L Primary Organic Adsorption 183.1 Primary organic adsorption 165L 176.9 Primary organic adsorption 175L 187.2 190L Primary Organic Adsorption 186.3 200L primary organic adsorption 188.5

[0048] 3. Results Analysis

[0049] According to the results in Table 2, 1L of organic resin showed good adsorption effect before treating 40 times the volume of industrial hydrogen peroxide, and the organic carbon content could be reduced to 70-130ppm. Before treating 165 times the volume of industrial hydrogen peroxide, it had a certain adsorption effect, but not much organic carbon was removed. After treating 165 times the volume of industrial hydrogen peroxide, the adsorption effect was very poor, and the organic carbon content was almost the same as that in the raw material of industrial-grade hydrogen peroxide, so regeneration was required.

[0050] One liter of organic adsorption resin can remove 5,000–6,000 ppm of organic carbon; however, in the method of this invention (using cation exchange resin to remove anthraquinones), one liter of strong acid macroporous cation exchange resin can remove 120,000–150,000 ppm of organic carbon, which is 20–30 times the amount of organic carbon removed by organic adsorption resin, a significant difference. While the brands and models of organic adsorption resins may differ somewhat, the manufacturing processes are generally the same, and the adsorption results will not differ significantly.

[0051] The method of this invention for removing organic carbon has a large removal capacity, good effect, long regeneration cycle, and requires less manpower, materials and generates less waste. It can significantly reduce the cost of organic carbon removal in industry.

[0052] The undescribed parts of this invention are the same as or implemented using existing technology. The applicant declares that this invention is illustrated through the above embodiments, but the invention is not limited to the above detailed methods, i.e., it does not mean that the invention must rely on the above detailed methods to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, additions of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

Claims

1. A method for removing anthraquinone compounds from industrial hydrogen peroxide, comprising using a two-stage acidic cation exchange resin, characterized in that... Industrial hydrogen peroxide is passed sequentially through primary and secondary antioxidant strong acid cation exchange resin columns at a flow rate of 5-10 times the resin volume per hour to obtain industrial hydrogen peroxide with low organic carbon content. The concentration of organic carbon in the industrial hydrogen peroxide solution is 50-1000 ppm, mainly anthraquinones. The carbonyl oxygen atom in the anthraquinone core structure has a lone pair of electrons, which can accept protons from the hydrogen peroxide solution and be removed by adsorption from the cation exchange resin. The hydrogen peroxide content is 27.5%-60%, and the operating temperature is 0-30℃. Once the first-stage cation exchange resin is saturated, it is regenerated using 5%~6% hydrochloric acid and then rinsed with ultrapure water; the second-stage cation exchange resin can be used for a long time.

2. The method according to claim 1, characterized in that: in, When regenerating the first-stage cation exchange resin, at a temperature not exceeding 30°C, first regenerate it with 6 times the resin volume of hydrochloric acid, and then wash it with 10 times the volume of ultrapure water.

3. The method according to claim 1, characterized in that: in, The antioxidant strong acid cation exchange resin is a macroporous strong acid cation exchange resin.

4. The method according to claim 1, characterized in that: in, The antioxidant strong acid cation exchange resin is a macroporous styrene cation exchange resin, a macroporous sulfonic acid cation exchange resin, or a macroporous hydrogen cation exchange resin.

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