Bisphenol A crystallization system
By connecting crystallization reactors in series and implementing automated control, the problem of low production efficiency caused by scaling in the crystallization reactors was solved, achieving long-term stable production of high-purity bisphenol A and maximizing equipment efficiency.
Patent Information
- Application Number
- CN202520165268.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2035-01-24
AI Technical Summary
Scaling in the crystallization reactor during the bisphenol A crystallization process leads to increased temperature, affecting production efficiency. This necessitates reducing the production load monthly for melting, resulting in low equipment utilization and increased costs.
Multiple crystallization reactors are connected in series via valves and pipelines to achieve automated control and temperature sensing of the crystallization reactors, ensuring that the remaining reactors operate normally while the target reactor is melting, thus avoiding a reduction in production load.
It achieves long-cycle, stable production of high-purity bisphenol A crystals, improves equipment utilization, reduces costs, ensures production continuity and product quality, and is highly automated, safe, and reliable.
Smart Images
Figure CN223788093U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chemical production technology, and in particular to a bisphenol A crystallization system. Background Technology
[0002] Bisphenol A, chemical name 2,2-bis(4-hydroxyphenyl)propane, trade name Bisphenol-A, abbreviated as BPA, molecular formula C 15 H 16 O2. The mainstream technology for bisphenol A production is the ion exchange resin method, which has the advantages of low corrosivity, low pollution, and easy catalyst separation. The main process of bisphenol A production involves phenol and acetone entering a fixed-bed reactor, where a condensation reaction occurs under the action of ion exchange resin catalyst and co-catalyst to produce bisphenol A. After dehydration and flash evaporation, the reaction liquid is an anhydrous bisphenol A-phenol solution. This solution then undergoes two stages of adduct crystallization and solid-liquid separation to obtain adduct crystals, which are then further dephenolized by flash evaporation and stripping. Finally, solid bisphenol A is obtained by granulation.
[0003] In the bisphenol A (BPA) production process, the BPA solution generally requires two crystallization stages to improve its quality and minimize the content of organic impurities. Common BPA crystallization techniques include suspension forced circulation cooling or hydrocarbon evaporation cooling. Each crystallization stage involves two crystallization reactors connected in series. Due to the inherent characteristics of crystallization technology, scaling occurs in the reactors after a certain period, preventing the reactor temperature from rising. Therefore, to ensure continuous production over a long period, the BPA crystallization process must be heated every month to melt the scale on the reactor walls. However, to maintain product quality and adapt to the melting operation of the crystallization reactor, the crystallization process must reduce its production load by approximately 40%–50%, with each reduction lasting about 130–140 hours. During this period, to maintain production balance, other production processes must also reduce their load accordingly, leading to underutilization of production equipment and increased investment costs.
[0004] Due to the inherent characteristics of the crystallization process in the bisphenol A production process, in order to ensure product quality and long-cycle production operation, the production load of the bisphenol A crystallization process must be reduced from 100% to 50% to 60% every month to adapt to the melting operation of the crystallization reactor. This results in the bisphenol A production unit not operating at full capacity for about 1,500 to 1,600 hours per year, thus failing to maximize the efficiency of the equipment. Utility Model Content
[0005] The purpose of this invention is to provide a bisphenol A crystallization system that can stably produce bisphenol A crystals over a long period of time.
[0006] The objective of this utility model can be achieved through the following technical solution: a bisphenol A crystallization system, comprising multiple crystallization reactors connected in series, with valves provided between adjacent crystallization reactors, each crystallization reactor being connected to a bisphenol A phenol solution inlet pipe via a bisphenol A phenol solution inlet branch pipe equipped with a valve, and each crystallization reactor being connected to a bisphenol A crystal outlet pipe via a bisphenol A crystal outlet branch pipe equipped with a valve.
[0007] Preferably, the crystallization reactor is an external circulation cooling crystallizer or a hydrocarbon evaporation crystallizer.
[0008] Preferably, the bisphenol A crystallization system includes crystallization reactor A, crystallization reactor B, and crystallization reactor C connected in series.
[0009] The crystallization reactors A, B, and C are each connected to a corresponding bisphenol A phenol solution feed branch pipe, and each bisphenol A phenol solution feed branch pipe is equipped with a feed valve. The crystallization reactors A, B, and C are each connected to a corresponding bisphenol A crystal discharge branch pipe, and each bisphenol A crystal discharge branch pipe is equipped with a discharge valve.
[0010] More preferably, an AB connecting valve is provided on the pipeline between the liquid outlet of the crystallization reactor A and the liquid inlet of the crystallization reactor B.
[0011] More preferably, a BC connecting valve is provided on the pipeline between the liquid outlet of the crystallization reactor B and the liquid inlet of the crystallization reactor C.
[0012] More preferably, the crystallization reactor A is connected to the bisphenol A phenol solution feed pipe through a first bisphenol A phenol solution feed branch pipe, and the first bisphenol A phenol solution feed branch pipe is provided with a first feed valve.
[0013] More preferably, the crystallization reactor B is connected to the bisphenol A phenol solution feed pipe through a second bisphenol A phenol solution feed branch pipe, and a second feed valve is provided on the second bisphenol A phenol solution feed branch pipe.
[0014] More preferably, the crystallization reactor C is connected to the bisphenol A phenol solution feed pipe through a third bisphenol A phenol solution feed branch pipe, and a third feed valve is provided on the third bisphenol A phenol solution feed branch pipe.
[0015] More preferably, the crystallization reactor A is connected to the bisphenol A crystal discharge pipe through a first bisphenol A crystal discharge branch pipe, and the first bisphenol A crystal discharge branch pipe is provided with a first discharge valve.
[0016] More preferably, the crystallization reactor B is connected to the bisphenol A crystal discharge pipe through a second bisphenol A crystal discharge branch pipe, and a second discharge valve is provided on the second bisphenol A crystal discharge branch pipe.
[0017] More preferably, the crystallization reactor C is connected to the bisphenol A crystal discharge pipe through a third bisphenol A crystal discharge branch pipe, and a third discharge valve is provided on the third bisphenol A crystal discharge branch pipe.
[0018] Preferably, in the bisphenol A crystallization system, the crystallization reactor at the end is connected to the crystallization reactor at the front end via a reflux pipeline, and a valve is provided on the reflux pipeline.
[0019] More preferably, the outlet of the crystallizing reactor at the end is connected to the inlet of the crystallizing reactor at the front via a reflux pipeline.
[0020] Preferably, the bisphenol A phenol solution inlet pipe is connected to a bisphenol A phenol solution storage tank.
[0021] Preferably, the bisphenol A crystal discharge pipe is connected to a solid-liquid separation device.
[0022] Preferably, the valve is an electric valve or a pneumatic valve.
[0023] More preferably, the valve is connected to a control mechanism.
[0024] More preferably, the crystallization reactor is equipped with a temperature sensor, which is connected to a control mechanism.
[0025] More preferably, the control mechanism includes a PLC controller.
[0026] Compared with the prior art, the present invention has the following beneficial effects:
[0027] 1. This utility model provides a bisphenol A crystallization system that can stably produce bisphenol A crystals over a long period of time;
[0028] 2. Through the coordinated design of the crystallization reactor, pipelines, and valves, this utility model allows the other crystallization reactors to operate normally while the target crystallization reactor is in the melting operation, which is beneficial for the long-term stable production of bisphenol A crystals;
[0029] 3. When performing melting operations on the target crystallization reactor, the production load and operating parameters of all processes in the bisphenol A production line do not need to be changed, which helps to maximize the efficiency of the equipment, make full use of the value of the production equipment, and reduce costs.
[0030] 4. This invention also facilitates the maintenance of crystallization reactors. When a crystallization reactor malfunctions, there is no need to stop the production operation, which is beneficial for long-term stable production of bisphenol A crystals.
[0031] 5. This utility model, through the combined setup of a temperature sensor and a control mechanism, can determine the target crystallization reactor for melting operations based on the temperature of the crystallization reactor, and automatically adjust the flow path by controlling the opening and closing of valves, resulting in a high degree of automation, enhanced safety and reliability, and higher efficiency.
[0032] 6. This invention can stably produce high-purity bisphenol A over a long period of time, with a purity of up to 99.95%. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the crystallization system of this utility model;
[0034] In the diagram: 1-Crystallization reactor A, 11-First feed valve, 12-First discharge valve, 2-Crystallization reactor B, 21-Second feed valve, 22-Second discharge valve, 3-Crystallization reactor C, 31-Third feed valve, 32-Third discharge valve, 102-AB connecting valve, 203-BC connecting valve, 301-CA connecting valve. Detailed Implementation
[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. This embodiment is based on the technical solution of the present invention and provides detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following embodiments.
[0036] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0037] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0038] Example 1
[0039] A bisphenol A crystallization system includes multiple crystallization reactors connected in series. In this embodiment, valves are provided between adjacent crystallization reactors. Each crystallization reactor is connected to a bisphenol A phenol solution inlet branch pipe and a bisphenol A crystal outlet branch pipe, and each bisphenol A phenol solution inlet branch pipe and bisphenol A crystal outlet branch pipe is equipped with a valve. Each crystallization reactor is connected to the bisphenol A phenol solution inlet pipe through a corresponding bisphenol A phenol solution inlet branch pipe and to the bisphenol A crystal outlet pipe through a corresponding bisphenol A crystal outlet branch pipe.
[0040] Example 2
[0041] A bisphenol A crystallization system, such as Figure 1As shown, the reactor includes crystallization reactors A1, B2, and C3 connected in series in a circulating manner. The outlet of crystallization reactor A1 is connected to the inlet of crystallization reactor B2 via a pipe, the outlet of crystallization reactor B2 is connected to the inlet of crystallization reactor C3 via a pipe, and the outlet of crystallization reactor C3 is connected to the inlet of crystallization reactor A1 via a pipe.
[0042] Furthermore, crystallization reactors A1, B2, and C3 are connected to the bisphenol A phenol solution feed pipe via the first bisphenol A phenol solution feed branch pipe, the second bisphenol A phenol solution feed branch pipe, and the third bisphenol A phenol solution feed branch pipe, respectively. Crystallization reactors A1, B2, and C3 are also connected to the bisphenol A crystal discharge pipe via the first bisphenol A crystal discharge branch pipe, the second bisphenol A crystal discharge branch pipe, and the third bisphenol A crystal discharge branch pipe, respectively.
[0043] Specifically, in this embodiment, an AB connecting valve 102 is installed on the pipeline between crystallization reactor A1 and crystallization reactor B2, a BC connecting valve 203 is installed on the pipeline between crystallization reactor B2 and crystallization reactor C3, and a CA connecting valve 301 is installed on the pipeline between crystallization reactor C3 and crystallization reactor A1. A first feed valve 11 is installed on the first bisphenol A phenol solution feed branch pipe, a second feed valve 21 is installed on the second bisphenol A phenol solution feed branch pipe, and a third feed valve 31 is installed on the third bisphenol A phenol solution feed branch pipe. A first discharge valve 12 is installed on the first bisphenol A crystal discharge branch pipe, a second discharge valve 22 is installed on the second bisphenol A crystal discharge branch pipe, and a third discharge valve 32 is installed on the third bisphenol A crystal discharge branch pipe.
[0044] The working principle of the crystallization system in this embodiment is as follows:
[0045] 1. When crystallization reactor C3 requires melting crystals, the bisphenol A phenol solution undergoes crystallization production operations in crystallization reactors A1 and B2. In this process, the first feed valve 11 → AB connecting valve 102 → second discharge valve 22 are open, while the second feed valve 21, third feed valve 31, first discharge valve 12, third discharge valve 32, BC connecting valve 203, and CA connecting valve 301 are closed. The bisphenol A phenol solution enters crystallization reactor A1 through the first bisphenol A phenol solution feed branch pipe. After initial crystallization, it enters crystallization reactor B2 for secondary crystallization. The resulting bisphenol A crystals are collected through the second bisphenol A crystal discharge branch pipe.
[0046] 2. When crystallization reactor A1 requires melting crystals, the bisphenol A phenol solution undergoes crystallization production operations in crystallization reactors B2 and C3. In this process, the second feed valve 21 → BC connecting valve 203 → third discharge valve 32 are open, while the first feed valve 11, third feed valve 31, first discharge valve 12, second discharge valve 22, AB connecting valve 102, and CA connecting valve 301 are closed. The bisphenol A phenol solution enters crystallization reactor B2 through the second bisphenol A phenol solution feed branch pipe, undergoes preliminary crystallization, and then enters crystallization reactor C3 for secondary crystallization. The resulting bisphenol A crystals are collected through the third bisphenol A crystal discharge branch pipe.
[0047] 3. When crystallization reactor B2 requires melting, the bisphenol A solution undergoes crystallization production via crystallization reactors C3 and A1. In this process, the third feed valve 31 → CA connecting valve 301 → first discharge valve 12 are open, while the first feed valve 11, second feed valve 21, second discharge valve 22, third discharge valve 32, AB connecting valve 102, and BC connecting valve 203 are closed. The bisphenol A solution enters crystallization reactor C3 via the third bisphenol A solution feed branch pipe, undergoes initial crystallization, and then enters crystallization reactor A1 for secondary crystallization. The resulting bisphenol A crystals are collected via the first bisphenol A crystal discharge branch pipe.
[0048] Example 3
[0049] This embodiment provides a crystallization method for long-cycle, stable production of high-purity bisphenol A. The two-stage crystallization process of the bisphenol A phenol solution is changed from two crystallization reactors in series in each stage to three crystallization reactors in series. Two automatic valves are added to the feed and discharge pipes of each crystallization reactor. Through the adjustment of these automatic valves, it is ensured that during the melting operation, two crystallization reactors in series operate online in each crystallization stage without reducing the production load. This guarantees the quality of the bisphenol A product and eliminates the need to reduce the production load of other bisphenol A processes.
[0050] Specifically, the production operation method for each crystallization process is as follows:
[0051] 1. When crystallization reactor C3 needs to melt crystals, the bisphenol A phenol solution is crystallized by crystallization reactors A1 and B2. In the process, the first feed valve 11 → AB connecting valve 102 → second discharge valve 22 are in the open state, while the second feed valve 21, third feed valve 31, first discharge valve 12, third discharge valve 32, BC connecting valve 203, and CA connecting valve 301 are in the closed state.
[0052] 2. When crystallization reactor A1 needs to melt crystals, the bisphenol A phenol solution is crystallized by crystallization reactors B2 and C3. In the process, the second feed valve 21 → BC connecting valve 203 → third discharge valve 32 are in the open state, while the first feed valve 11, the third feed valve 31, the first discharge valve 12, the second discharge valve 22, the AB connecting valve 102, and the CA connecting valve 301 are in the closed state.
[0053] 3. When crystallization reactor B2 needs to melt crystals, the bisphenol A phenol solution is crystallized by crystallization reactors C3 and A1. In the process, the third feed valve 31 → CA connecting valve 301 → first discharge valve 12 are in the open state, while the first feed valve 11, second feed valve 21, second discharge valve 22, third discharge valve 32, AB connecting valve 102, and BC connecting valve 203 are in the closed state.
[0054] In this embodiment, the crystallization temperature is 50-70°C, the concentration of bisphenol A in the bisphenol A solution is 23-40 wt%, and the purity of the bisphenol A obtained by crystallization can reach 99.95%.
[0055] Example 4
[0056] The 200,000-ton-per-year bisphenol A production unit was optimized and upgraded using the crystallization method described in Example 3. One crystallizer and four automatic valves were added to each of the two crystallization processes, with a planned investment of approximately 7 million yuan. This production unit will increase the annual output of bisphenol A by approximately 17,100 tons. The sales price of each ton of bisphenol A is planned to be 12,000 yuan. This production unit will increase the annual output value by approximately 205.2 million yuan and the profit by approximately 18.46 million yuan. The investment cost will be recovered in approximately 4.5 months.
[0057] Example 5
[0058] The 240,000-ton-per-year bisphenol A production unit was optimized and upgraded using the crystallization method described in Example 3. One crystallizer and four automatic valves were added to each of the two crystallization processes, with a planned investment of approximately RMB 7.55 million. This production unit will increase the annual output of bisphenol A by approximately 20,500 tons. The sales price of each ton of bisphenol A is planned to be RMB 12,000. The annual output value of this production line will increase by approximately RMB 246 million, and the profit will increase by approximately RMB 22.14 million. The investment cost will be recovered in approximately 4.1 months.
[0059] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.
Claims
1. A bisphenol A crystallization system characterized by, The crystallization reactor comprises a plurality of crystallization reactors connected in series, valves are arranged between adjacent crystallization reactors, each crystallization reactor is connected with a bisphenol A phenol solution feeding pipe through a bisphenol A phenol solution feeding branch pipe provided with a valve, and each crystallization reactor is connected with a bisphenol A crystal discharging pipe through a bisphenol A crystal discharging branch pipe provided with a valve.
2. The bisphenol A crystallization system of claim 1, wherein, The crystallization reactor comprises a plurality of crystallization reactors connected in series, valves are arranged between adjacent crystallization reactors, each crystallization reactor is connected with a bisphenol A phenol solution feeding pipe through a bisphenol A phenol solution feeding branch pipe provided with a valve, and each crystallization reactor is connected with a bisphenol A crystal discharging pipe through a bisphenol A crystal discharging branch pipe provided with a valve. The crystallization reactor comprises a plurality of crystallization reactors connected in series, valves are arranged between adjacent crystallization reactors, each crystallization reactor is connected with a bisphenol A phenol solution feeding pipe through a bisphenol A phenol solution feeding branch pipe provided with a valve, and each crystallization reactor is connected with a bisphenol A crystal discharging pipe through a bisphenol A crystal discharging branch pipe provided with a valve.
3. The bisphenol A crystallization system of claim 2, wherein, An AB communication valve (102) is arranged on the pipeline between the liquid outlet of the crystallization reactor A (1) and the liquid inlet of the crystallization reactor B (2). An AB communication valve (102) is arranged on the pipeline between the liquid outlet of the crystallization reactor A (1) and the liquid inlet of the crystallization reactor B (2).
4. The bisphenol A crystallization system of claim 2, wherein, The crystallization reactor A (1) is connected with the bisphenol A phenol solution feeding pipe through the first bisphenol A phenol solution feeding branch pipe, and the first bisphenol A phenol solution feeding branch pipe is provided with a first feeding valve (11). The crystallization reactor B (2) is connected with the bisphenol A phenol solution feeding pipe through the second bisphenol A phenol solution feeding branch pipe, and the second bisphenol A phenol solution feeding branch pipe is provided with a second feeding valve (21). The crystallization reactor C (3) is connected with the bisphenol A phenol solution feeding pipe through the third bisphenol A phenol solution feeding branch pipe, and the third bisphenol A phenol solution feeding branch pipe is provided with a third feeding valve (31).
5. The bisphenol A crystallization system of claim 2, wherein, The crystallization reactor A (1) is connected with the bisphenol A crystal discharging pipe through the first bisphenol A crystal discharging branch pipe, and the first bisphenol A crystal discharging branch pipe is provided with a first discharging valve (12). The crystallization reactor B (2) is connected with the bisphenol A crystal discharging pipe through the second bisphenol A crystal discharging branch pipe, and the second bisphenol A crystal discharging branch pipe is provided with a second discharging valve (22). The crystallization reactor C (3) is connected with the bisphenol A crystal discharging pipe through the third bisphenol A crystal discharging branch pipe, and the third bisphenol A crystal discharging branch pipe is provided with a third discharging valve (32).
6. The bisphenol A crystallization system of claim 1, wherein, The crystallization reactor at the end is connected with the crystallization reactor at the front end through a reflux pipeline, and a valve is arranged on the reflux pipeline.
7. The bisphenol A crystallization system of claim 1, wherein, The bisphenol A phenol solution feeding pipe is connected with a bisphenol A phenol solution storage tank.
8. The bisphenol A crystallization system of claim 1, wherein, The bisphenol A crystal discharging pipe is connected with a solid-liquid separation device.
9. The bisphenol A crystallization system of claim 1, wherein, The valve is an electric valve or a pneumatic valve, and the valve is connected with a control mechanism.
10. The bisphenol A crystallization system of claim 9, wherein, A temperature sensor is arranged on the crystallization reactor, and the temperature sensor is connected with the control mechanism.