A process and apparatus for the removal of p-tert-butylcatechol from chemical products

Abstract

The application discloses a method for removing p-tert-butyl catechol in chemicals, which comprises the following steps: mixing a to-be-processed solution with a compounded auxiliary agent, the compounded auxiliary agent reacting with the p-tert-butyl catechol in the to-be-processed solution to make the p-tert-butyl catechol precipitate from the solution; stirring the solution after the reaction to promote further reaction; performing solid-liquid separation on the solution after the further reaction to remove solid precipitates; and further removing the p-tert-butyl catechol in the solution by using a detergent after the separation of the solution; wherein the compounded auxiliary agent comprises sodium hydroxide, a surfactant and an auxiliary agent, and the auxiliary agent comprises a fatty acid polyethylene glycol ester. The method has the advantages of high removal efficiency and low removal cost. The application further discloses a device for removing p-tert-butyl catechol in chemicals, which is used for realizing the method for removing p-tert-butyl catechol in chemicals.

Description

TECHNICAL FIELD

[0001] The present application relates to the chemical technology field, and in particular to a method and device for removing p-tert-butyl catechol from chemicals. BACKGROUND

[0002] As a polymerization inhibitor, p-tert-butyl catechol is widely used in the fields of synthetic resins, rubber, medicine, pesticide, etc. For example, in the storage or transportation process of certain chemicals, p-tert-butyl catechol needs to be added to prevent polymerization reaction and avoid affecting the quality of the chemicals. When the chemicals need to be used, p-tert-butyl catechol in the chemicals needs to be removed. If the removal is not sufficient, it may affect the normal use of the chemicals. Meanwhile, when the content of p-tert-butyl catechol in the chemicals is too high, it may also cause certain harm to the human body and the environment. Therefore, it is necessary to develop an efficient and reliable method for removing p-tert-butyl catechol to achieve high-efficiency removal.

[0003] In the prior art, common methods for removing p-tert-butyl catechol include distillation method, active carbon adsorption method, etc. The distillation method removes p-tert-butyl catechol from chemicals by taking advantage of the different boiling points of p-tert-butyl catechol and chemicals, but this method has high cost and low efficiency. The active carbon adsorption method uses active carbon to adsorb the solution containing p-tert-butyl catechol and remove the substance from the solution, but once the active carbon is saturated, it needs to be replaced in time, which has high labor cost and low efficiency, and the cost of disposing of the hazardous waste is also high. SUMMARY

[0004] To solve the above problems, the present application provides a method for removing p-tert-butyl catechol from chemicals. The method reacts p-tert-butyl catechol with a compounded additive to precipitate p-tert-butyl catechol from the solution, and further removes the residual p-tert-butyl catechol component in the solution by using a detergent, which has high removal efficiency and low processing cost. The present application also provides a device for removing p-tert-butyl catechol from chemicals.

[0005] To achieve the above purpose, the present application provides the following technical solutions:

[0006] A method for removing p-tert-butyl catechol from chemicals, comprising the following steps:

[0007] S1, mixing a to-be-processed solution with a compounded additive, and reacting the compounded additive with p-tert-butyl catechol in the to-be-processed solution to precipitate p-tert-butyl catechol from the solution;

[0008] S2, stirring the solution after the reaction in step S1 to promote further reaction of the compounded additive with the to-be-processed solution;

[0009] S3, solid-liquid separation is performed on the solution after the reaction in step S2, and solid precipitates are removed;

[0010] S4, the solution after the separation in step S3 is further treated by a detergent to remove p-tert-butylcatechol in the solution;

[0011] The complexing agent comprises sodium hydroxide, a surfactant, and an auxiliary agent, and the auxiliary agent comprises a fatty acid polyethylene glycol ester.

[0012] As a further description of the technical scheme of the application, the complexing agent comprises 65-70% of sodium hydroxide, 0.1-5% of a surfactant, and 2.5-7.5% of an auxiliary agent.

[0013] As a further description of the technical scheme of the application, the complexing agent comprises 70% of sodium hydroxide, 1% of a surfactant, and 7.5% of an auxiliary agent.

[0014] As a further description of the technical scheme of the application, the reaction temperature in step S2 is 50-80°C, and the reaction time is 10 minutes.

[0015] As a further description of the technical scheme of the application, the solid-liquid separation in step S3 is performed by natural sedimentation and stratification, and the time for natural sedimentation and stratification is ≥8 minutes.

[0016] As a further description of the technical scheme of the application, the detergent comprises an alkyl alcohol amide.

[0017] The application also provides a device for removing p-tert-butylcatechol from a chemical product, which is used to implement the method for removing p-tert-butylcatechol from a chemical product, and comprises a mixing mechanism, a reaction mechanism, a separation mechanism, and a washing mechanism, which are sequentially connected through communication pipelines.

[0018] The mixing mechanism is used to implement step S1, the reaction mechanism is used to implement step S2, the separation mechanism is used to implement step S3, and the washing mechanism is used to implement step S4.

[0019] As a further description of the technical scheme of the application, the mixing mechanism is provided with a first feeding pipe and a second feeding pipe, the first feeding pipe is used to feed a solution to be treated into the mixing mechanism, and the second feeding pipe is used to feed a complexing agent into the mixing mechanism.

[0020] As a further description of the technical scheme of the application, the reaction mechanism comprises a stirring unit.

[0021] As a further description of the technical scheme of the application, the number of the mixing mechanisms is plural.

[0022] Based on the technical scheme, the application achieves the following technical effects:

[0023] 1. The method for removing p-tert-butyl catechol from chemicals provided by the application, by reacting the p-tert-butyl catechol in the solution to be treated with the compounded auxiliary agent, the p-tert-butyl catechol is precipitated from the solution. Further removal of the residual p-tert-butyl catechol in the solution is carried out by the detergent, which can achieve high-efficiency removal effect and low processing cost.

[0024] 2. The device for removing p-tert-butyl catechol from chemicals provided by the application, the mixing mechanism, the reaction mechanism, the separation mechanism and the washing mechanism connected in sequence by the communication pipeline respectively realize steps S1, S2, S3 and S4, and the mechanisms are connected to form an integral whole, which can realize continuous removal process, can realize large-scale processing, and is beneficial to improve the removal efficiency and reduce the processing cost. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 Fig. 1 is a structural schematic diagram of a device for removing p-tert-butyl catechol from chemicals according to the application;

[0026] Figure 2 Fig. 2 is a structural schematic diagram of a mixing mechanism of a device for removing p-tert-butyl catechol from chemicals according to the application;

[0027] Figure 3 Fig. 3 is a structural schematic diagram of a reaction mechanism of a device for removing p-tert-butyl catechol from chemicals according to the application.

[0028] 1-mixing mechanism; 11-first feeding pipe; 12-second feeding pipe; 2-reaction mechanism; 21-stirring unit; 3-separation mechanism; 4-washing mechanism. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the application, the application will be described more fully below with reference to the accompanying drawings and specific embodiments. The preferred embodiments of the application are shown in the drawings. However, the application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the application more thorough and comprehensive.

[0030] It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intervening element.

[0031] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is usually placed, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application herein are only for the purpose of describing the specific embodiments and are not intended to limit the present application.

[0033] In a first aspect, the present application provides a method for removing p-tert-butylcatechol from a chemical product, comprising the following steps:

[0034] S1, mixing the to-be-processed solution with a compounded auxiliary agent, the compounded auxiliary agent reacting with the p-tert-butylcatechol in the to-be-processed solution to precipitate the p-tert-butylcatechol from the solution;

[0035] S2, stirring the solution after step S1 to promote further reaction between the compounded auxiliary agent and the to-be-processed solution;

[0036] S3, performing solid-liquid separation on the solution after step S2 to remove the solid precipitate;

[0037] S4, further removing the p-tert-butylcatechol from the solution after step S3 by using a detergent;

[0038] The compounded auxiliary agent includes sodium hydroxide, a surfactant and an auxiliary agent, and the auxiliary agent includes a fatty acid polyethylene glycol ester. Sodium hydroxide is a strong base with strong reactivity and selectivity, and can react with p-tert-butylcatechol to generate phenolic sodium salt, so as to precipitate the p-tert-butylcatechol from the solution. The surfactant can reduce the interfacial tension, increase the contact area between sodium hydroxide and p-tert-butylcatechol, and improve the reaction efficiency. The surfactant can be a non-ionic surfactant, an anionic surfactant or a cationic surfactant, etc. The auxiliary agent includes a fatty acid polyethylene glycol ester, which can improve the solubility and stability of the compounded auxiliary agent, improve the reactivity and selectivity, and enhance the reaction effect with p-tert-butylcatechol. Therefore, the use of the compounded auxiliary agent to remove p-tert-butylcatechol from the to-be-processed solution can achieve high-efficiency removal, and the material used is simple and the processing cost is low.

[0039] Specifically, the complexing agent includes 65-70% of sodium hydroxide, 0.1-5% of surfactant and 2.5-7.5% of auxiliary agent, preferably, the complexing agent includes 70% of sodium hydroxide, 1% of surfactant and 7.5% of auxiliary agent. Since sodium hydroxide reacts with p-tert-butyl catechol to generate sodium phenolate, and sodium phenolate is easily soluble in water, setting 65-70% of sodium hydroxide can increase the proportion of sodium hydroxide in the complexing agent, thereby reducing the proportion of water in the complexing agent. A large proportion of sodium hydroxide can precipitate more p-tert-butyl catechol to generate sodium phenolate precipitate, and a small proportion of water can only dissolve a small amount of sodium phenolate, so most of the sodium phenolate exists in the form of precipitate, thereby most of the p-tert-butyl catechol component can be removed by solid-liquid separation, and the stripping process is simpler, easier to operate and has higher stripping efficiency.

[0040] The reaction temperature of step S2 is 50-80°C, and the reaction time is 10 minutes. Setting a lower reaction temperature of 50-80°C can reduce the solubility of the generated sodium phenolate, so that the p-tert-butyl catechol is better separated from the solution, which is beneficial to improve the stripping efficiency.

[0041] Step S3 is solid-liquid separation by natural sedimentation and layering, and the time of natural sedimentation and layering is ≥8 minutes. Since most of the generated sodium phenolate exists in the form of precipitate, the precipitate can be separated from the solution by natural sedimentation and layering for a certain time. The solid-liquid separation by natural sedimentation and layering is simple to operate and can reduce energy consumption and processing cost.

[0042] Further, the washing agent includes alkyl alcohol amide. The alkyl alcohol amide has good solubility and detergency, and can effectively dissolve the residual sodium phenolate precipitate in the solution, so as to remove the residual p-tert-butyl catechol component in the solution. It can be understood that the p-tert-butyl catechol mainly acts as a polymerization inhibitor for olefin monomers, and therefore the solution to be treated usually includes olefin monomers. The olefin monomers are not easily soluble in water, and the washing agent usually contains a large amount of water, so the solution to be treated and the washing agent are not mutually soluble. After the washing agent dissolves the p-tert-butyl catechol component from the solution, the washing agent and the treated solution can be separated by natural layering. Further removing the residual p-tert-butyl catechol component in the solution by using the washing agent can make the p-tert-butyl catechol component in the solution be removed more completely, thereby effectively improving the stripping efficiency.

[0043] In a second aspect, the present application further provides a device for stripping p-tert-butyl catechol from a chemical product, which is used to realize the above-mentioned method for stripping p-tert-butyl catechol from a chemical product, and the device includes Figure 1, including a mixing mechanism 1, a reaction mechanism 2, a separation mechanism 3 and a washing mechanism 4, which are connected in sequence through communication pipelines. The mixing mechanism 1 is used to realize step S1, the reaction mechanism 2 is used to realize step S2, the separation mechanism 3 is used to realize step S3, and the washing mechanism 4 is used to realize step S4. The mechanisms are connected through communication pipelines to form a whole, which can realize the continuity of the stripping process, realize large-scale processing, improve the stripping efficiency, and reduce the processing cost; and the device structure is simple, the operation is convenient, and it can be applied to large-scale applications.

[0044] Specifically, the upper part of the mixing mechanism 1 is provided with a communication pipeline leading to the upper part of the reaction mechanism 2, the lower part of the reaction mechanism 2 is provided with a communication pipeline leading to the upper part of the separation mechanism 3, another position above the separation mechanism 3 is provided with a communication pipeline leading to the upper part of the washing mechanism 4, and another position above the washing mechanism 4 is provided with an output pipeline for outputting the processed solution. The respective communication pipelines and output pipelines are provided with corresponding valves for controlling the input and output of materials.

[0045] Further, a discharge pipeline is arranged below the mixing mechanism 1 to discharge the precipitate precipitated in the preliminary reaction; a discharge pipeline is arranged below the separation mechanism 3 to discharge the precipitate separated; and a discharge pipeline is arranged below the washing mechanism 4 to discharge the washing agent after washing. The solid-liquid waste discharged from each discharge pipeline can be discharged to a treatment station for treatment.

[0046] Further, with reference to Figure 2 , the mixing mechanism 1 is provided with a first feeding pipe 11 and a second feeding pipe 12. The first feeding pipe 11 is used to introduce the solution to be treated into the mixing mechanism 1, and the second feeding pipe 12 is used to introduce the complexing agent into the mixing mechanism 1. The first feeding pipe 11 and the second feeding pipe 12 can be arranged side by side in the middle and lower part of the mixing mechanism 1. When the solution to be treated is introduced into the first feeding pipe 11 and the complexing agent is introduced into the second feeding pipe 12 at the same time, more uniform mixing can be achieved, so that the p-tert-butyl catechol in the solution to be treated can react more fully with the complexing agent, and the stripping efficiency of p-tert-butyl catechol can be improved.

[0047] Further, with reference to Figure 3 , the reaction mechanism 2 includes a stirring unit 21. The stirring unit 21 can be arranged at the center position of the reaction mechanism 2 and extends from the upper part of the reaction mechanism 2 to the middle and lower part of the reaction mechanism 2, so as to increase the contact area between the stirring unit 21 and the solution, realize sufficient stirring of the solution, accelerate the collision between the complexing agent and the p-tert-butyl catechol molecules, further promote the reaction between the complexing agent and the p-tert-butyl catechol, and improve the stripping efficiency.

[0048] Further, the number of mixing mechanisms 1 is multiple. Since the mixing mechanism 1 mainly realizes the mixing of the compounded auxiliary agent and the solution to be treated, the compounded auxiliary agent and the p-tert-butyl catechol in the solution to be treated are preliminarily reacted. The advantage of setting multiple mixing mechanisms 1 is that the solution to be treated can be distributed to multiple mixing mechanisms 1 and preliminarily reacted with the compounded auxiliary agent in each mixing mechanism 1, avoiding the phenomenon of uneven mixing and insufficient reaction caused by large-scale mixing.

[0049] Example 1

[0050] In this embodiment, the compounded auxiliary agent A composed of 70% sodium hydroxide, 27.4% water, 0.1% surfactant and 2.5% auxiliary agent is used to remove p-tert-butyl catechol from the solution containing 1000 ppm p-tert-butyl catechol by the method of removing p-tert-butyl catechol from the chemical product. The specific steps are as follows:

[0051] S1, mix the solution containing 1000 ppm p-tert-butyl catechol with the compounded auxiliary agent A, and the p-tert-butyl catechol in the solution reacts with the compounded auxiliary agent A to precipitate p-tert-butyl catechol from the solution;

[0052] S2, stir the solution after step S1 to promote further reaction between the compounded auxiliary agent A and the solution;

[0053] S3, solid-liquid separation is performed on the solution after step S2 to remove the solid precipitate;

[0054] S4, the solution after step S3 is further treated with a detergent to remove p-tert-butyl catechol from the solution;

[0055] Example 2

[0056] In this embodiment, the compounded auxiliary agent B composed of 70% sodium hydroxide, 24% water, 1% surfactant and 5% auxiliary agent is used to remove p-tert-butyl catechol from the solution containing 1000 ppm p-tert-butyl catechol by the method of removing p-tert-butyl catechol from the chemical product. The specific steps are the same as in Example 1.

[0057] Example 3

[0058] In this embodiment, the compounded auxiliary agent C composed of 70% sodium hydroxide, 20% water, 5% surfactant and 5% auxiliary agent is used to remove p-tert-butyl catechol from the solution containing 1000 ppm p-tert-butyl catechol by the method of removing p-tert-butyl catechol from the chemical product. The specific steps are the same as in Example 1.

[0059] Example 4

[0060] In this embodiment, the complexing agent D is prepared by using 70% of sodium hydroxide, 21.5% of water, 1% of surfactant and 7.5% of auxiliary agent, and the solution containing 1000 ppm of p-tert-butyl catechol is treated by the method for removing p-tert-butyl catechol from the removal chemicals. The specific steps are the same as those in Example 1.

[0061] Example 5

[0062] In this embodiment, the complexing agent E is prepared by using 65% of sodium hydroxide, 29% of water, 1% of surfactant and 5% of auxiliary agent, and the solution containing 1000 ppm of p-tert-butyl catechol is treated by the method for removing p-tert-butyl catechol from the removal chemicals. The specific steps are the same as those in Example 1.

[0063] Comparative Example 1

[0064] In this comparative example, the solution containing 1000 ppm of p-tert-butyl catechol is treated by the traditional distillation method.

[0065] Comparative Example 2

[0066] In this comparative example, the solution containing 1000 ppm of p-tert-butyl catechol is treated by the traditional activated carbon adsorption method.

[0067] Test Example 1

[0068] In this test example, the content of p-tert-butyl catechol in the treated solution in Examples 1 to 5 and Comparative Examples 1 to 2 is detected respectively, and the removal efficiency of p-tert-butyl catechol is calculated, and the calculation results are shown in Table 1.

[0069] Table 1 Removal efficiency of p-tert-butyl catechol in Examples 1 to 5 and Comparative Examples 1 to 2

[0070] Examples / Comparative Examples p-tert-butylcatechol elimination efficiency Example 1 98.2％ Example 2 99.5％ Example 3 99％ Example 4 99.6％ Example 5 95％ Comparative Example 1 70％ Comparative Example 2 75％

[0071] By comparing Examples 1 to 5 with Comparative Examples 1 to 2, it can be seen that the removal efficiency of p-tert-butyl catechol in the solution to be treated by the method for removing p-tert-butyl catechol from the removal chemicals provided by the present application is much higher than that by the traditional distillation method and activated carbon adsorption method, and the removal efficiency is as high as 95% or more, which has better removal effect.

[0072] Test Example 2

[0073] In this test example, the related data of treatment time, treatment cost and environmental impact degree of Example 1, Comparative Example 1 and Comparative Example 2 are compared, and the corresponding data of Example 1, Comparative Example 1 and Comparative Example 2 are shown in Table 2.

[0074] Table 2 processing time, processing cost and environmental impact degree of example 1, comparative example 1 and comparative example 2

[0075]

[0076] It can be known by comparison that the method for removing p-tert-butyl catechol from the chemical product provided by the application has lower processing time and processing cost than the traditional distillation method and activated carbon adsorption method, effectively reduces the processing cost, has smaller environmental impact degree, and has certain environmental protection value and practical value.

[0077] The above content is merely an example and description of the structure of the application, which is more specific and detailed, but should not be construed as limiting the scope of the patent of the application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the application, several modifications and improvements can be made, and these obvious replacement forms belong to the protection scope of the application.

Claims

1. A process for the removal of p-tert-butylcatechol from a chemical product, characterized in that, The method comprises the following steps: S1, mixing the to-be-processed solution with a compounded auxiliary agent, and reacting the compounded auxiliary agent with p-tert-butyl catechol in the to-be-processed solution to precipitate the p-tert-butyl catechol from the solution; S2, stirring the solution after the reaction in step S1 to promote further reaction of the compounded auxiliary agent with the to-be-processed solution; S3, performing solid-liquid separation on the solution after the reaction in step S2 to remove solid precipitates; S4, further removing p-tert-butyl catechol in the solution by using a detergent after the separation in step S3; The compounded auxiliary agent comprises 65-70% of sodium hydroxide, 0.1-5% of a surfactant, and 2.5-7.5% of an auxiliary agent, the auxiliary agent comprises a fatty acid polyethylene glycol ester, and the detergent comprises an alkyl alcohol amide.

2. The method of removing p-tert-butylcatechol from a chemical product according to claim 1, wherein The compounded auxiliary agent comprises 70% of sodium hydroxide, 1% of a surfactant, and 7.5% of an auxiliary agent.

3. The method of removing p-tert-butylcatechol from a chemical product of claim 1, wherein, The reaction temperature in step S2 is 50-80℃, and the reaction time is 10 minutes.

4. The method of removing p-tert-butylcatechol from a chemical product of claim 1, wherein, The solid-liquid separation in step S3 is performed by natural sedimentation and layering, and the time for natural sedimentation and layering is ≥8 minutes.

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