Deacidification system for bisphenol A production

Abstract

The utility model discloses an acid removal system for bisphenol A production, the bisphenol A production system comprises a distillation unit and a reaction unit, an anion reactor is connected between the distillation unit and the reaction unit through a pipeline, and a catalyst is filled in the anion reactor. According to the deacidification system for bisphenol A production provided by the utility model, the anion reactor is arranged between the distillation unit and the reaction unit, so that mother liquor firstly enters the anion reactor and then enters the reaction unit after being dehydrated, and in the anion reactor, the mother liquor and a catalyst are subjected to neutralization reaction to remove acidic substances in the mother liquor; the influence of acidic substances in the mother liquor on the product quality is avoided as much as possible.

Description

Technical Field

[0001] The utility model relates to the technical field of bisphenol A production, in particular to an acid removal system for bisphenol A production. Background Art

[0002] Bisphenol A is produced commercially by the condensation reaction of acetone and two equivalents of phenol in the presence of a catalyst such as an ion exchange resin. Bisphenol A is a high-volume compound, with an estimated annual production worldwide exceeding 2 million tons.

[0003] For example, the patent document with the authorization announcement number CN109476572B, the authorization announcement date February 11, 2022, and the name "Method for Continuously Producing Bisphenol A" includes reacting phenol and acetone in the presence of an acidic catalyst to form a product mixture comprising bisphenol A and phenol; directing the product mixture to a crystallization unit comprising a crystallization container and a heat exchanger for cooling the product mixture; and crystallizing bisphenol A-phenol adduct crystals from the product mixture in the crystallization unit to form a suspension of crystals.

[0004] The mother liquor in the bisphenol A production process contains a small amount of sulfonic acid group acidic substances lost from the main reactor catalyst and sulfuric acid added during the neutralization process of the dephenolization unit. These acidic substances will accumulate in the system. If a small amount of acidic substances is mixed into the refining unit, it will cause micro-decomposition of bisphenol A, thereby degrading and worsening the product quality. Utility Model Content

[0005] The utility model aims to provide an acid removal system for bisphenol A production to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A deacidification system for producing bisphenol A comprises a distillation unit and a reaction unit. An anion reactor is connected between the distillation unit and the reaction unit via a pipeline. A catalyst is loaded in the anion reactor.

[0008] A heat exchanger is provided at the input end of the anion reactor.

[0009] In the above-mentioned acid removal system for producing bisphenol A, the temperature of the mother liquor at the input end of the anion reactor is 70-80°C.

[0010] In the above-mentioned acid removal system for producing bisphenol A, a pipeline filter is provided at the input end of the anion reactor.

[0011] In the above-mentioned acid removal system for producing bisphenol A, a discharge filter is provided at the output end of the anion reactor.

[0012] In the above-mentioned acid removal system for producing bisphenol A, both the input end and the output end of the anion reactor are provided with an acidity detection unit.

[0013] In the above-mentioned acid removal system for producing bisphenol A, the catalyst is loaded into the anion reactor through a filter structure.

[0014] The above-mentioned acid removal system for bisphenol A production also includes a liquid alkali dripping system.

[0015] In the above-mentioned acid removal system for producing bisphenol A, the liquid alkali dripping system continuously drips alkali into the system through a metering pump connected to the alkali liquid supply tank.

[0016] In the above-mentioned acid removal system for producing bisphenol A, the volume concentration of the alkali solution is 5%.

[0017] In the above technical scheme, the utility model provides an acid removal system for bisphenol A production, in which an anion reactor is arranged between the distillation unit and the reaction unit, so that the mother liquor enters the anion reactor first and then enters the reaction unit after dehydration. In the anion reactor, the mother liquor and the catalyst undergo a neutralization reaction to remove the acidic substances in the mother liquor, thereby minimizing the influence of the acidic substances in the mother liquor on the product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present utility model. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0019] Figure 1 Anion reactor pipeline flow chart provided for an embodiment of the utility model;

[0020] Figure 2 A pipeline flow chart of a liquid caustic soda dripping system provided in an embodiment of the utility model.

[0021] Description of reference numerals:

[0022] 1. Distillation unit; 2. Reaction unit; 3. Anion reactor; 4. Heat exchanger; 5. Pipeline filter; 6. Discharge filter; 7. Liquid alkali supply tank; 8. Metering pump. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0024] Reference Figure 1-2The embodiment of the utility model provides an acid removal system for producing bisphenol A, wherein the bisphenol A production system comprises a distillation unit 1 and a reaction unit 2, wherein an anion reactor 3 is connected between the distillation unit 1 and the reaction unit 2 via a pipeline, and wherein the anion reactor 3 is filled with a catalyst.

[0025] Specifically, the bisphenol A production system in the prior art is generally a circulation pipeline, which includes a distillation unit 1 and a reaction unit 2. The distillation unit 1 is used to distill and dehydrate the mother liquor and pentane, and the reaction unit 2 is used to carry out the production reaction of bisphenol A on the mother liquor. In the mother liquor of the bisphenol A production process, there is a small amount of sulfonic acid group acidic substances lost from the main reactor catalyst and sulfuric acid added during the neutralization process of the dephenolization unit. These acidic substances will accumulate in the system. For the refining unit, these acidic substances will cause micro-decomposition of bisphenol A, which will lead to degradation and deterioration of the product quality of the refining unit. The innovation of the embodiment of the utility model is that an anion reactor 3 is connected between the distillation unit 1 and the reaction unit 2 through a pipeline, the input end of the anion reactor 3 is connected to the distillation unit 1 through a pipeline, and the output end is connected to the reaction unit 2 through a pipeline. The anion reactor 3 is a tank body, which is filled with a catalyst (the catalyst is an ion exchange resin catalyst). It is configured so that the mother liquor enters the anion reactor 3 first and then enters the reaction unit 2 after being dehydrated in the distillation unit 1. In the anion reactor 3, the mother liquor and the catalyst undergo a neutralization reaction to remove the acidic substances in the mother liquor, so as to minimize the influence of the acidic substances in the mother liquor on the quality of the product.

[0026] The neutralization reaction occurring in the anion reactor 3 is as follows:

[0027] X―N:RnHm+X'―SO3:H→X―N:RnHmH SO3―X'

[0028] X, R and X' respectively represent the structure of the anion exchange resin, the alkyl group and the structure of the acidic substance lost from the cation exchange resin; wherein the catalyst is an ion exchange resin catalyst, and the amount of the catalyst is determined according to the processing capacity of the anion reactor 3.

[0029] An acid removal system for bisphenol A production provided by an embodiment of the utility model is provided with an anion reactor 3 between a distillation unit 1 and a reaction unit 2, so that the mother liquor first enters the anion reactor 3 and then enters the reaction unit 2 after dehydration. In the anion reactor 3, the mother liquor reacts with the catalyst to neutralize to remove the acidic substances in the mother liquor, so as to avoid the acidic substances in the mother liquor from affecting the product quality as much as possible.

[0030] In another embodiment provided by the utility model, further, a heat exchanger 4 is provided at the input end of the anion reactor 3. Specifically, the heat exchanger 4 is provided at the input end of the anion reactor 3, so that the mother liquor passes through the heat exchanger 4 for heat exchange before entering the anion reactor 3 from the distillation unit 1; when the mother liquor enters the anion reactor 3 from the distillation unit 1, its temperature is generally 90°C. In order to reduce the temperature of the mother liquor to a temperature more suitable for its neutralization reaction, a heat exchanger 4 is provided at the input end of the anion reactor 3, and 45°C hot water can be input into the heat exchanger 4 for heat exchange with the mother liquor, so that the mother liquor can be cooled to make the mother liquor better for neutralization reaction. In some special production systems, the mother liquor does not need to be dehydrated through the distillation unit 1. At this time, the temperature of the mother liquor when entering the heat exchanger 4 is generally 50°C. In this way, 100°C hot water can be input into the heat exchanger 4 to increase the temperature of the mother liquor, so as to facilitate the neutralization reaction of the mother liquor.

[0031] Preferably, the temperature of the mother liquid at the input end of the anion reactor 3 is 70-80° C. Specifically, the heat exchange efficiency of the heat exchanger 4 can be changed by setting the temperature or flux of the hot water in the heat exchanger 4, and it is appropriate to cool or heat the mother liquid to 70-80° C. The temperature of the mother liquid within this range can improve the efficiency of the neutralization reaction.

[0032] Furthermore, a pipeline filter 5 is provided at the input end of the anion reactor 3. Specifically, some impurities will be generated in the production system of bisphenol A, so a pipeline filter 5 is provided at the input end of the anion reactor 3, and the pipeline filter 5 is preferably a wedge-shaped mesh filter, so that the mother liquor entering the anion reactor 3 can be filtered through the pipeline filter 5.

[0033] Further, the output end of the anion reactor 3 is provided with a discharge filter 6. Specifically, some impurities will be generated after the neutralization reaction in the anion reactor 3. In order to prevent the impurities from entering the next process, the discharge filter 6 is provided at the output end of the anion reactor 3 to filter the mother liquor after the reaction through the discharge filter 6.

[0034] Preferably, an acidity detection unit is provided at both the input and output ends of the anion reactor 3. Specifically, the acidity detection unit can detect the acidity (i.e., pH value) of the mother liquor, and the anion reactor 3 can be monitored by comparing the acidity at the input and output ends of the anion reactor 3, thereby realizing intelligent production.

[0035] Further, the catalyst is loaded into the anion reactor 3 through a filter structure. Specifically, the filter structure has a small pore size, which can effectively prevent the catalyst from running away, so that the catalyst can be loaded into the anion reactor 3 through the filter structure, which facilitates the neutralization reaction of the mother liquor when it passes through the anion reactor 3.

[0036] In another embodiment provided by the utility model, a liquid caustic soda dripping system is also included. Specifically, the liquid caustic soda is alkaline, and it can also be mixed with the mother liquor to undergo a neutralization reaction, so the liquid caustic soda dripping system can be provided while the anion reactor 3 is provided, and the two cooperate to improve the acid removal efficiency.

[0037] Preferably, the liquid alkali dripping system continuously drips alkali into the system through a metering pump 8 connected to a liquid alkali supply tank 7. Specifically, the liquid alkali supply tank 7 is used to store liquid alkali, the input end of the metering pump 8 is connected to the liquid alkali supply tank 7, and the output end is connected to the pipeline of the bisphenol A production system, so that the liquid alkali can be quantitatively input into the production pipeline through the metering pump 8 to minimize the content of acidic substances in the mother liquor.

[0038] Preferably, the volume concentration of the alkali solution is 5%. Specifically, in this embodiment, NaOH and deionized water are mixed to form an alkali solution with a volume concentration of 5%.

[0039] The above only describes some exemplary embodiments of the present invention by way of illustration. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A deacidification system for the production of bisphenol A, the production system of bisphenol A comprising a distillation unit and a reaction unit, characterized in that: An anion reactor is connected between the distillation unit and the reaction unit via a pipeline, and a catalyst is filled in the anion reactor.

2. The acid removal system for producing bisphenol A according to claim 1, characterized in that: A heat exchanger is provided at the input end of the anion reactor.

3. A deacidification system for bisphenol A production according to claim 2, characterized in that: The temperature of the mother liquid at the input end of the anion reactor is 70-80°C.

4. The acid removal system for producing bisphenol A according to claim 1, characterized in that: The input end of the anion reactor is provided with a pipeline filter.

5. The acid removal system for producing bisphenol A according to claim 1, characterized in that: The output end of the anion reactor is provided with a discharge filter.

6. The acid removal system for producing bisphenol A according to claim 1, characterized in that: The input end and the output end of the anion reactor are both provided with acidity detection units.

7. The acid removal system for producing bisphenol A according to claim 1, characterized in that: The catalyst is loaded into the anion reactor through a filter structure.

8. The acid removal system for producing bisphenol A according to claim 1, characterized in that: Also includes a liquid caustic soda dripping system.

9. The acid removal system for producing bisphenol A according to claim 8, characterized in that: The liquid alkali dripping system continuously drips alkali into the system through a metering pump connected to the alkali liquid supply tank.

10. The acid removal system for producing bisphenol A according to claim 9, characterized in that: The volume concentration of the alkali solution is 5%.

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