Chlorobenzene and ketonic acid solution separation process

Abstract

The invention discloses a chlorobenzene and ketonic acid solution separation process. The chlorobenzene and ketonic acid solution separation process comprises the following steps: S1, primary water washing; s2, secondary water washing; s3, chlorobenzene distillation; and S4, chlorobenzene drying. Compared with the prior art, the chlorobenzene and ketonic acid solution separation process provided by the invention has the advantages of high separation efficiency, low cost, environmental protection and safety.

Description

Technical Field

[0001] The present application relates to the technical field of chlorobenzene separation technology, and in particular to a chlorobenzene and keto acid solution separation technology. Background Art

[0002] The traditional separation process of chlorobenzene and keto acid solution is a complex multi-step process involving water washing, alkali dissolution, petroleum ether extraction, acid precipitation, filter pressing and dehydration, chlorobenzene drying, chlorobenzene distillation, and petroleum ether distillation. The following is a description of the traditional process flow and the existing technical problems.

[0003] S1, washing with acylated washing water or hot water, promoting oil-water separation by heating, and separating the chlorobenzene phase from the water phase; S2, use fresh water to carry out a second water wash to further purify the chlorobenzene phase; S3, sending the chlorobenzene phase into an alkali dissolving kettle, adding water and concentrated alkali solution, carrying out alkali dissolving treatment, and further separating the oil-water phase; S4, adding petroleum ether, stirring and standing to separate the water phase from the petroleum ether phase, acid precipitation of the water phase, and recovery or distillation of the petroleum ether phase; S5, acid precipitation of the aqueous phase, adjusting the pH value, and further processing the product in the aqueous phase; S6. The material after acid precipitation is filtered and then vacuum dried in a dehydration kettle to remove moisture. The separated chlorobenzene is dried to remove possible entrained moisture.

[0004] S7. The dried chlorobenzene is distilled to remove impurities and improve purity.

[0005] S8. Distill the petroleum ether washing liquid, recover the petroleum ether and treat the chlorobenzene residual liquid.

[0006] Although the traditional separation process of chlorobenzene and ketoacid solution can achieve effective separation, its complex and multi-step characteristics bring significant technical challenges and environmental safety issues. The repeated heating, water washing, alkali dissolution, petroleum ether extraction, acid precipitation, filter pressing, drying and distillation in the process not only lead to huge energy consumption, but also significantly increase the complexity of operation and increase the risk of error. In particular, the widespread use of strong acids, strong bases and organic solvents such as petroleum ether not only accelerates the corrosion of production equipment and increases maintenance costs, but also produces a large amount of wastewater that requires additional treatment, posing a potential threat to the environment. More importantly, the high volatility and flammability of petroleum ether make it a major safety hazard in the entire process, which is prone to fire and explosion accidents. In summary, the traditional process has obvious deficiencies in efficiency, energy consumption, safety and environmental protection. It is urgently needed to introduce innovative technologies to optimize the process, reduce energy consumption, improve safety, and reduce the impact on the environment, so as to achieve a greener and more efficient production method. Summary of the invention

[0007] In order to solve at least one of the above technical problems, a low-cost, high-efficiency, safe and environmentally friendly chlorobenzene and keto acid solution separation process is developed. The present application provides a chlorobenzene and keto acid solution separation process.

[0008] In a first aspect, the present application provides a chlorobenzene and keto acid solution separation process, the chlorobenzene and keto acid solution separation process comprising the following steps: S1, a first water wash; S2, a second water wash; S3, chlorobenzene distillation; S4, chlorobenzene drying; A water wash includes the following steps: S1.1, add hot water from the acylation hot water pump to the acylation hot water reactor containing chlorobenzene and keto acid solution, and interlock and close the acylation hot water pump and the acylation hot water reactor valve; S1.2, the jacket system of the acylation hot water reactor is switched to steam heating mode, the temperature is raised to 80-85°C, water washing is performed and the reactor is allowed to stand to separate the materials into chlorobenzene phase and water phase; S1.3, after stratification, the lower chlorobenzene phase is transferred to the ketoacid reaction liquid tank through a centrifugal pump, and the upper aqueous phase is discharged to the acylation washing water tank; S1.4, drain the circulating water of the acylation hot water reactor and prepare for the next step; The secondary washing process includes the following steps: S2.1, returning the chlorobenzene phase collected in the ketoacid reaction tank in step S1.3 to the acylation hot water reactor, adding hot water from the acylation hot water pump, and interlocking and closing the acylation hot water pump and the acylation hot water reactor valve; S2.2, the jacket system of the acylation hot water reactor is switched to the steam heating mode, the temperature is raised to 80-85°C, and water washing is performed and allowed to stand to cause the material to be separated into a chlorobenzene phase and a water phase; S2.3, after stratification, the lower chlorobenzene phase is transferred to the ketoacid reaction liquid tank through a centrifugal pump, and the upper aqueous phase is discharged to the acylation washing water tank; Chlorobenzene distillation includes the following steps: S3.1. Open the condenser of the chlorobenzene still to preheat the chlorobenzene still, transfer the chlorobenzene phase in the ketoacid reaction tank to the chlorobenzene still through the ketoacid chlorobenzene solution delivery pump, turn on the jacket steam heating of the chlorobenzene still to start distillation; add hot water to the chlorobenzene still for atmospheric distillation, collect chlorobenzene in the waste chlorobenzene pump, close the jacket steam valve of the chlorobenzene still when no chlorobenzene is evaporated, let it stand for 5 to 10 minutes, and after the materials are separated, discharge the lower layer of ketoacid melt into the dehydration kettle, and then discharge the upper layer of acidic wastewater into the collection tank, and use it as hydrolysis water after cooling; Chlorobenzene drying includes the following steps: S4.1. Transfer the chlorobenzene collected by the waste chlorobenzene pump to the chlorobenzene agglomerator for preliminary dehydration and drying.

[0009] By adopting the above technical scheme, a chlorobenzene and keto acid solution separation process proposed in the present application significantly improves the separation efficiency, reduces energy consumption, and reduces the impact on the environment through optimized water washing, distillation and drying steps, thereby ensuring the safety of the production process. Specifically: First water washing (S1): By adding hot water to the acylation hot water reactor and heating it to 80-85°C, the rapid stratification of chlorobenzene and water is promoted, and the preliminary separation of the chlorobenzene phase and the water phase is achieved. This step effectively removes most of the water-soluble impurities and simplifies the subsequent treatment process. Secondary water washing (S2): The preliminarily separated chlorobenzene phase is washed again to further purify the chlorobenzene phase, remove residual water-soluble impurities, and improve the purity of chlorobenzene. At the same time, it avoids the use of strong acids, strong bases or petroleum ether and other reagents that may cause safety and environmental problems. Chlorobenzene distillation (S3): atmospheric distillation is used to evaporate chlorobenzene by heating, while high-boiling-point substances such as keto acids remain at the bottom of the kettle, achieving effective separation of chlorobenzene and keto acids, avoiding the increased energy consumption and equipment loss that may be caused by high temperature in the traditional distillation process, and reducing potential pollution to the environment. Chlorobenzene drying (S4): the chlorobenzene obtained by distillation is transferred to a chlorobenzene agglomerator for preliminary dehydration and drying, which effectively removes residual moisture, ensures the purity and stability of chlorobenzene, and avoids the safety hazards caused by the use of organic solvents such as petroleum ether for drying. In addition, this process attaches importance to the rational use of water resources, reduces the discharge of harmful wastewater, and recycles the hydrolysis water after cooling, reflecting an environmentally friendly attitude and the concept of sustainable development, which is in line with the current development trend of green chemical industry.

[0010] In summary, the separation process of chlorobenzene and keto acid solution provided in this application not only improves separation efficiency and reduces energy consumption by streamlining and optimizing steps, but also avoids the use of chemicals that may cause safety and environmental problems, achieving multiple goals of cost-effectiveness, environmental friendliness and production safety. This technical solution provides a greener and more efficient solution for the separation of similar substances in chemical production, and has significant technical advantages and application prospects.

[0011] Optionally, the water washing treatment time in step S1.2 is 0.5 to 1.5 hours, and the resting time is 0.5 to 1 hour.

[0012] By adopting the above technical solution, that is, setting the water washing treatment time to 0.5 to 1.5 hours and the static time to 0.5 to 1 hour in step S1.2, the following technical effects can be achieved: Setting a reasonable water washing treatment time ensures the effective separation of chlorobenzene and the water phase, avoiding incomplete separation due to too short a treatment time and waste of resources due to too long a treatment time. Appropriate standing time is conducive to the full stratification of the material, ensuring the clear separation of the chlorobenzene phase and the water phase, and improving the accuracy and efficiency of subsequent operations. Through the precise control of the water washing and standing time, the process flow can be arranged reasonably, avoiding production delays or idle resources caused by improper time control, and maintaining a stable production rhythm. Reasonable time setting helps to maintain the quality standards of chlorobenzene and keto acid separation, ensures the purity and consistency of the final product, and meets the strict requirements of downstream applications. By optimizing the operation time, unnecessary heating and cooling cycles are reduced, energy consumption is reduced, and the amount of wastewater that may be generated due to excessive operation is also reduced, which is in line with the principles of energy conservation, emission reduction and environmentally friendly production.

[0013] In summary, the above technical solution achieves comprehensive optimization of separation efficiency, product quality, production rhythm and energy conservation and emission reduction through precise control of water washing and standing time, and embodies the lean management concept in fine chemical production.

[0014] Optionally, the washing time in step S2.2 is 0.5 to 1.5 hours, and the resting time is 0.5 to 1 hour.

[0015] Optionally, the distillation temperature of the steam heating distillation in step S3.1 is 90-105° C. and the time is 30 min.

[0016] By adopting the above technical solution, by adopting the technical solution of setting the temperature of steam heating distillation to 90-105°C and the duration to 30 minutes in step S3.1, the following technical effects can be achieved: Distillation within the specified temperature range can effectively promote the evaporation of chlorobenzene, while avoiding the increase in energy consumption and possible side reactions caused by excessively high temperatures, ensuring the efficiency and controllability of the distillation process. Controlling the distillation temperature within an appropriate range is conducive to the separation of chlorobenzene from high-boiling point substances such as ketoacids, improving the purity of the final product, and meeting the demand for high-quality chlorobenzene. Setting the distillation time to 30 minutes not only ensures the full progress of the distillation process, but also avoids production delays caused by too long distillation, which helps to improve the overall production efficiency. Precisely controlled distillation conditions reduce unnecessary heating and cooling cycles, reduce energy consumption, comply with the production principle of energy conservation and emission reduction, and are conducive to cost control. Distillation within a safe temperature range reduces safety risks that may be caused by excessively high temperatures, such as equipment damage or fire, and ensures the safety of operators and equipment. Fixed temperature and time parameters facilitate real-time monitoring and adjustment when necessary, ensuring the stability and repeatability of the distillation process, and facilitating the refined management of the production process. In summary, by setting specific temperature and time parameters in the chlorobenzene distillation step, not only the distillation efficiency and product purity are optimized, but also the focus on production safety and energy conservation and emission reduction is reflected, which is a key measure to achieve efficient, safe and green chemical production.

[0017] The time for standing and separating the materials in step S3.1 is 5-10 minutes.

[0018] Optionally, the flow rate of transferring chlorobenzene to the chlorobenzene coalescer in step S4.1 is 1 m / s. 3 / h.

[0019] By adopting the above technical solution, by using chlorobenzene at 1m 3 The technical solution of transferring the flow rate of 1000 t / h to the chlorobenzene coalescer can achieve the following technical effects: the set flow rate ensures the residence time of chlorobenzene in the coalescer, promotes the full separation of water and the drying of chlorobenzene, improves the drying efficiency, and ensures the quality of the final product. The constant and moderate flow rate avoids incomplete drying due to too fast a flow rate or increased energy consumption due to too slow a flow rate, realizes the effective use of energy, and reduces production costs. 1m 3The flow rate of 1.25 / h matches the processing capacity of the coalescer, avoiding overload operation or idle capacity of the equipment, and improving the utilization rate and production efficiency of the equipment. The stable flow rate reduces the internal pressure fluctuations of the equipment that may be caused by sudden changes in flow rate, reduces operational risks, and ensures the safety and stability of the production process. The set flow rate is convenient for real-time monitoring and adjustment, ensuring the accurate execution of process parameters, facilitating the timely detection and correction of potential process deviations, and ensuring the smooth progress of the production process. The constant flow rate helps to maintain the stability of the drying process, reduces product quality fluctuations caused by changes in flow rate, and improves product consistency and reliability. In summary, by setting 1m 3 / h flow rate is transferred to the agglomerator, which not only optimizes the efficiency and energy consumption of the drying process, but also reflects the comprehensive consideration of product quality, production safety and equipment efficiency. It is an important technical means to achieve the goals of high quality, high efficiency and low cost in fine chemical production.

[0020] In summary, the present invention includes at least one of the following beneficial technical effects: 1. Through the accurately controlled washing and distillation steps, the present invention can efficiently separate chlorobenzene and keto acid, significantly improve the separation efficiency, and reduce the time and resources required for separation compared to the traditional process. By adopting optimized heating and distillation conditions, the separation task can be completed at a lower energy consumption, reducing energy consumption, reducing production costs, and reducing greenhouse gas emissions, which meets the requirements of green production. Avoid the use of flammable and toxic organic solvents such as petroleum ether, reduce potential pollution to the environment, reduce the generation of wastewater, simplify the wastewater treatment process, and reduce environmental protection costs. Remove the potential safety hazards such as fire and explosion in traditional processes, and create a safer production environment through safe washing and distillation operations, protecting the health and safety of operators. In addition, this process attaches importance to the rational use of water resources, reduces the discharge of harmful wastewater, and recycles the hydrolysis water after cooling, embodies the friendly attitude towards the environment and the concept of sustainable development, and is in line with the current development trend of green chemical industry. Combined with the above-mentioned technical effects, the separation process of the present invention shows significant cost-effectiveness in reducing energy consumption, reducing waste treatment costs, and improving product purity, providing enterprises with a more competitive production process. DETAILED DESCRIPTION

[0021] The present application is further described in detail below with reference to the embodiments. Specific embodiments

[0022] Example 1 This embodiment provides a process for separating chlorobenzene and keto acid solution, comprising the following steps: S1, primary water washing; S2, secondary water washing; S3, chlorobenzene distillation; S4, chlorobenzene drying; The water washing process includes the following steps: Add hot water (temperature is 80°C) from the acylation hot water pump to the acylation hot water reactor containing chlorobenzene and keto acid solution, and after measuring 3000 kg of hot water with a flow meter, interlock and close the acylation hot water pump and the acylation hot water reactor valve; The jacket of the acylation hot water reactor was switched to steam, and the reactor was heated to 80°C, washed with water for 0.5h, and allowed to stand for 0.5h; the material was separated into chlorobenzene phase and water phase; The lower chlorobenzene phase is transferred into the ketoacid reaction liquid tank by using the ketoacid chlorobenzene solution delivery pump (when the oil-water two-phase interface appears in the long sight glass in front of the pump, continue pumping for 15 seconds and then stop the pump to ensure that there is no chlorobenzene phase in the pipeline), and the upper aqueous phase is discharged into the acylation washing water tank by using the ketoacid chlorobenzene solution delivery pump; The cold medium in the jacket of the acylation hot water reactor is converted into the hot medium: first open the drain valve at the bottom of the reactor jacket, then slowly open the air inlet on the upper part of the reactor jacket, fill air into the jacket, and press out the circulating water in the jacket to the ditch; when the water in the jacket is drained, close the two valves and let in steam normally.

[0023] Secondary washing: with fresh water Use the keto acid reaction liquid pump to return all the chlorobenzene phase in the keto acid reaction liquid tank to the acylation hot water reactor, and add 3000 kg of fresh water (interlocked valve closed) with a flow meter; open the jacket steam of the acylation hot water reactor to heat the reactor to 80°C, wash with water for 0.5h, and let it stand for 0.5h; separate the materials into chlorobenzene phase and water phase; The lower chlorobenzene phase is transferred into the ketoacid reaction liquid tank by using a ketoacid chlorobenzene solution pump (when the oil-water two-phase interface appears in the long sight glass in front of the pump, continue pumping for 1 minute and then stop the pump to ensure that there is no chlorobenzene phase in the pipeline), and the upper aqueous phase is discharged into the acylation washing water tank by using a ketoacid chlorobenzene solution delivery pump.

[0024] Chlorobenzene distillation The chlorobenzene reaction liquid in the ketoacid reaction liquid tank is divided into one chlorobenzene distillation kettle for chlorobenzene distillation treatment, that is, the chlorobenzene phase in each chlorobenzene distillation kettle is divided into two consecutive treatments, each time about 3600kg.

[0025] Check whether the bottom valve of the chlorobenzene distillation kettle is closed, open the cooling water of the chlorobenzene distillation condenser, and slightly open the steam to preheat the chlorobenzene distillation kettle. Pump the hydrolyzed material into the chlorobenzene distillation kettle through the ketoacid chlorobenzene solution delivery pump. Note that the volume of the material liquid generally does not exceed 2 / 3 of the kettle volume. Slowly open the chlorobenzene distillation kettle jacket steam heating and start distillation. Pay attention to controlling the opening of the steam valve and control the temperature at 90°C to prevent the material in the kettle from boiling and rushing.

[0026] During the distillation process, check whether the interface of the water separator is clear, check the temperature of the chlorobenzene distillation condenser, the level gauge of the first and second level oil-water separators of chlorobenzene, and the outlet sight glass, and confirm that chlorobenzene enters the first, second and third level salt drying tanks smoothly.

[0027] After half an hour of distillation, add about 250 kg of hot water to continue atmospheric distillation. When the interface is stable and there is no fluctuation, and it is confirmed on site that no chlorobenzene is evaporated, the distillation can be considered to be over. At the same time, close the jacket steam valve of the chlorobenzene distillation kettle. Stop stirring the chlorobenzene distillation kettle, let the material stand for 5 to 10 minutes, open the discharge bottom valve, observe carefully through the bottom discharge pipe sight glass, and discharge the keto acid into the dehydration kettle. After the keto acid is discharged, discharge the upper acidic wastewater into the acid water collection tank and use it as hydrolysis water after cooling.

[0028] Operation Notes: The temperature of the distilled keto acid liquid is very high, so be careful not to get burned during the discharge process. Before discharging the keto acid into the dehydration kettle, make sure that the pipeline from the bottom valve of the distillation kettle to the dehydration kettle is unobstructed, and be sure to close the drain valve to prevent the liquid from being discharged into the acid water collection tank.

[0029] The following is a list of abnormal conditions in the distillation process and their treatment measures; Table 1- Chlorobenzene drying Waste chlorobenzene pump with 1m 3 / h flow rate, the chlorobenzene in the waste chlorine tank is sent to the chlorobenzene agglomerator to separate the possible entrained water, and then dried in the chlorobenzene dryer and stored in the dry chlorobenzene tank for standby use.

[0030] When the chlorobenzene coalescer is used for the first time, when the equipment is U-bend discharging, slightly open the upper drain valve to exhaust the air in the equipment; when the liquid level gauge is full, close the drain valve to complete the exhaust.

[0031] According to the amount of sewage, the chlorobenzene coalescer (control the oil-water two-phase interface at 0-5 scales from the upper end of the level gauge) and the chlorobenzene dryer are drained once every shift or every day, and the sewage is discharged to the ditch and then flows into the underground pool in the south. When the equipment is discharging sewage, carefully observe the sewage sight glass and be careful not to discharge chlorobenzene outside the equipment.

[0032] Example 2 The difference between this embodiment and embodiment 1 is that it includes the following steps: The water washing process includes the following steps: Add hot water (temperature is 80°C) from the acylation hot water pump to the acylation hot water reactor containing chlorobenzene and keto acid solution, and after measuring 3000 kg of hot water with a flow meter, interlock and close the acylation hot water pump and the acylation hot water reactor valve; The jacket of the acylation hot water reactor was switched to steam, and the reactor was heated to 83°C, washed with water for 1 hour, and allowed to stand for 0.8 hours; the material was separated into chlorobenzene phase and water phase; The lower chlorobenzene phase is transferred into the ketoacid reaction liquid tank by using the ketoacid chlorobenzene solution delivery pump (when the oil-water two-phase interface appears in the long sight glass in front of the pump, continue pumping for 18 seconds and then stop the pump to ensure that there is no chlorobenzene phase in the pipeline), and the upper aqueous phase is discharged into the acylation washing water tank by using the ketoacid chlorobenzene solution delivery pump; The cold medium in the jacket of the acylation hot water reactor is converted into the hot medium: first open the drain valve at the bottom of the reactor jacket, then slowly open the air inlet on the upper part of the reactor jacket, fill air into the jacket, and press out the circulating water in the jacket to the ditch; when the water in the jacket is drained, close the two valves and let in steam normally.

[0033] Secondary washing: with fresh water Use the keto acid reaction liquid pump to return all the chlorobenzene phase in the keto acid reaction liquid tank to the acylation hot water reactor, and add 3000 kg of fresh water (interlocked valve closed) with a flow meter; open the jacket steam of the acylation hot water reactor to heat the reactor to 83°C, wash with water for 1 hour, and let it stand for 0.7 hours; separate the materials into chlorobenzene phase and water phase; The lower chlorobenzene phase is transferred into the ketoacid reaction liquid tank by using a ketoacid chlorobenzene solution pump (when the oil-water two-phase interface appears in the long sight glass in front of the pump, continue pumping for 1 minute and then stop the pump to ensure that there is no chlorobenzene phase in the pipeline), and the upper aqueous phase is discharged into the acylation washing water tank by using a ketoacid chlorobenzene solution delivery pump.

[0034] Chlorobenzene distillation The chlorobenzene reaction liquid in the ketoacid reaction liquid tank is divided into one chlorobenzene distillation kettle for chlorobenzene distillation treatment, that is, the chlorobenzene phase in each chlorobenzene distillation kettle is divided into two consecutive treatments, each time about 3600kg.

[0035] Check whether the bottom valve of the chlorobenzene distillation kettle is closed, open the cooling water of the chlorobenzene distillation condenser, and slightly open the steam to preheat the chlorobenzene distillation kettle. Pump the hydrolyzed material into the chlorobenzene distillation kettle through the ketoacid chlorobenzene solution delivery pump. Note that the volume of the material liquid generally does not exceed 2 / 3 of the kettle volume. Slowly open the chlorobenzene distillation kettle jacket steam heating and start distillation. Pay attention to controlling the opening of the steam valve and control the temperature at 100°C to prevent the material in the kettle from boiling and rushing.

[0036] During the distillation process, check whether the interface of the water separator is clear, check the temperature of the chlorobenzene distillation condenser, the level gauge of the first and second level oil-water separators of chlorobenzene, and the outlet sight glass, and confirm that chlorobenzene enters the first, second and third level salt drying tanks smoothly.

[0037] After half an hour of distillation, add about 250 kg of hot water to continue atmospheric distillation. When the interface is stable and there is no fluctuation, and it is confirmed on site that no chlorobenzene is evaporated, the distillation can be considered to be over. At the same time, close the jacket steam valve of the chlorobenzene distillation kettle. Stop stirring the chlorobenzene distillation kettle, let the material stand for 7 minutes, open the bottom valve of the discharge, observe carefully through the bottom discharge pipe sight glass, and discharge the keto acid into the dehydration kettle. After the keto acid is discharged, discharge the upper acidic wastewater into the acid water collection tank and use it as hydrolysis water after cooling.

[0038] Chlorobenzene drying Waste chlorobenzene pump with 1m 3 / h flow rate, the chlorobenzene in the waste chlorine tank is sent to the chlorobenzene agglomerator to separate the possible entrained water, and then dried in the chlorobenzene dryer and stored in the dry chlorobenzene tank for standby use.

[0039] When the chlorobenzene coalescer is used for the first time, when the equipment is U-bend discharging, slightly open the upper drain valve to exhaust the air in the equipment; when the liquid level gauge is full, close the drain valve to complete the exhaust.

[0040] According to the amount of sewage, the chlorobenzene coalescer (control the oil-water two-phase interface at 0-5 scales from the upper end of the level gauge) and the chlorobenzene dryer are drained once every shift or every day, and the sewage is discharged to the ditch and then flows into the underground pool in the south. When the equipment is discharging sewage, carefully observe the sewage sight glass and be careful not to discharge chlorobenzene outside the equipment.

[0041] Example 3 The water washing process includes the following steps: Add hot water (temperature is 80°C) from the acylation hot water pump to the acylation hot water reactor containing chlorobenzene and keto acid solution, and after measuring 3000 kg of hot water with a flow meter, interlock and close the acylation hot water pump and the acylation hot water reactor valve; The jacket of the acylation hot water reactor was switched to steam, and the reactor was heated to 85°C, washed with water for 1.5 hours, and allowed to stand for 1 hour; the material was separated into chlorobenzene phase and water phase; The lower chlorobenzene phase is transferred into the ketoacid reaction liquid tank by using the ketoacid chlorobenzene solution delivery pump (when the oil-water two-phase interface appears in the long sight glass in front of the pump, continue pumping for 20 seconds and then stop the pump to ensure that there is no chlorobenzene phase in the pipeline), and the upper aqueous phase is discharged into the acylation washing water tank by using the ketoacid chlorobenzene solution delivery pump; The cold medium in the jacket of the acylation hot water reactor is converted into the hot medium: first open the drain valve at the bottom of the reactor jacket, then slowly open the air inlet on the upper part of the reactor jacket, fill air into the jacket, and press out the circulating water in the jacket to the ditch; when the water in the jacket is drained, close the two valves and let in steam normally.

[0042] Secondary washing: with fresh water Use the keto acid reaction liquid pump to return all the chlorobenzene phase in the keto acid reaction liquid tank to the acylation hot water reactor, and add 3000 kg of fresh water (interlocked valve closed) with a flow meter; open the jacket steam of the acylation hot water reactor to heat the reactor to 85°C, wash with water for 1.5 hours, and let it stand for 1 hour; separate the materials into chlorobenzene phase and water phase; The lower chlorobenzene phase is transferred into the ketoacid reaction liquid tank by using a ketoacid chlorobenzene solution pump (when the oil-water two-phase interface appears in the long sight glass in front of the pump, continue pumping for 1 minute and then stop the pump to ensure that there is no chlorobenzene phase in the pipeline), and the upper aqueous phase is discharged into the acylation washing water tank by using a ketoacid chlorobenzene solution delivery pump.

[0043] Chlorobenzene distillation The chlorobenzene reaction liquid in the ketoacid reaction liquid tank is divided into one chlorobenzene distillation kettle for chlorobenzene distillation treatment, that is, the chlorobenzene phase in each chlorobenzene distillation kettle is divided into two consecutive treatments, each time about 3600kg.

[0044] Check whether the bottom valve of the chlorobenzene distillation kettle is closed, open the cooling water of the chlorobenzene distillation condenser, and slightly open the steam to preheat the chlorobenzene distillation kettle. Pump the hydrolyzed material into the chlorobenzene distillation kettle through the ketoacid chlorobenzene solution delivery pump. Note that the volume of the liquid should not exceed 2 / 3 of the kettle volume. Slowly open the steam heating of the jacket of the chlorobenzene distillation kettle and start distillation. Pay attention to controlling the opening of the steam valve and control the temperature at 105℃ to prevent the material in the kettle from boiling and rushing.

[0045] During the distillation process, check whether the interface of the water separator is clear, check the temperature of the chlorobenzene distillation condenser, the level gauge of the first and second level oil-water separators of chlorobenzene, and the outlet sight glass, and confirm that chlorobenzene enters the first, second and third level salt drying tanks smoothly.

[0046] After half an hour of distillation, add about 250 kg of hot water to continue atmospheric distillation. When the interface is stable and there is no fluctuation, and it is confirmed on site that no chlorobenzene is evaporated, the distillation can be considered to be over. At the same time, close the jacket steam valve of the chlorobenzene distillation kettle. Stop stirring the chlorobenzene distillation kettle, let the material stand for 10 minutes, open the discharge bottom valve, observe carefully through the bottom discharge pipe sight glass, and discharge the keto acid into the dehydration kettle. After the keto acid is discharged, discharge the upper acidic wastewater into the acid water collection tank and use it as hydrolysis water after cooling.

[0047] Operation Notes: The temperature of the distilled keto acid liquid is very high, so be careful not to get burned during the discharge process. Before discharging the keto acid into the dehydration kettle, make sure that the pipeline from the bottom valve of the distillation kettle to the dehydration kettle is unobstructed, and be sure to close the drain valve to prevent the liquid from being discharged into the acid water collection tank.

[0048] The following is a list of abnormal conditions and treatment measures in the distillation process; Table 1- Chlorobenzene drying Waste chlorobenzene pump with 1m 3 / h flow rate, the chlorobenzene in the waste chlorine tank is sent to the chlorobenzene agglomerator to separate the possible entrained water, and then dried in the chlorobenzene dryer and stored in the dry chlorobenzene tank for standby use.

[0049] When the chlorobenzene coalescer is used for the first time, when the equipment is U-bend discharging, slightly open the upper drain valve to exhaust the air in the equipment; when the liquid level gauge is full, close the drain valve to complete the exhaust.

[0050] According to the amount of sewage, the chlorobenzene coalescer (control the oil-water two-phase interface at 0-5 scales from the upper end of the level gauge) and the chlorobenzene dryer are drained once every shift or every day, and the sewage is discharged to the ditch and then flows into the underground pool in the south. When the equipment is discharging sewage, carefully observe the sewage sight glass and be careful not to discharge chlorobenzene outside the equipment.

[0051] Comparative Example 1 This comparative example provides a traditional process for separating chlorobenzene and ketoacid solution, comprising the following steps: S1, primary water washing; S2, secondary water washing; S3, alkali dissolution; S4, acid precipitation; S5, filter pressing and dehydration; S6, chlorobenzene drying; S7, chlorobenzene distillation; S8, petroleum ether distillation.

[0052] The water washing process includes the following steps: S1.1, add hot water (temperature is 80°C) from the acylation hot water pump to the acylation hot water reactor containing chlorobenzene and keto acid solution, measure 3000 kg of hot water with a flow meter, and then interlock and close the acylation hot water pump and the acylation hot water reactor valve; S1.2, the jacket system of the acylation hot water reactor is switched to steam heating mode, the temperature is raised to 85°C, and the reactor is washed with water for 0.5h and allowed to stand for 0.5h to separate the materials into chlorobenzene phase and water phase; S1.3, after stratification, transfer the chlorobenzene phase of the lower layer to the ketoacid reaction liquid tank through a centrifugal pump (when the oil-water two-phase interface appears in the long sight glass in front of the pump, continue pumping for 20 seconds and then stop the pump to ensure that there is no chlorobenzene phase in the pipeline), and discharge the upper water phase to the acylation wash water tank; S1.4. Convert the refrigerant in the kettle jacket of the acylation hot water pump into the heat medium. First, open the drain valve at the bottom of the kettle jacket, then slowly open the air inlet at the top of the kettle jacket, fill the jacket with air, and press out the circulating water in the jacket to the ditch; when the water in the jacket is drained, close the two valves and let in steam normally; The secondary washing process includes the following steps: S2.1, returning the chlorobenzene phase collected in the ketoacid reaction tank in step S1.3 to the acylation hot water reactor, adding hot water from the acylation hot water pump, and interlocking and closing the acylation hot water pump and the acylation hot water reactor valve; S2.2, the jacket system of the acylation hot water reactor is switched to steam heating mode, the temperature is raised to 85°C, water washing is performed and the reactor is allowed to stand to separate the materials into chlorobenzene phase and water phase; S2.3, after stratification, the lower chlorobenzene phase is transferred to the ketoacid reaction liquid tank through a centrifugal pump, and the upper aqueous phase is discharged to the acylation washing water tank; Alkaline dissolution includes the following steps: S3.1. Add 2300 kg of water to the alkali solution kettle, start stirring, and add 250 kg of concentrated alkali solution with a mass fraction concentration of 30% from the concentrated alkali high-level tank, then divide the chlorobenzene phase in the ketoacid reaction liquid tank into two equal parts (one part weighs 2400 kg), use the ketoacid reaction liquid pump to transport one part of the chlorobenzene phase to the alkali solution kettle, stir for 0.5 h, and let it stand for 1 h to fully separate the oil and water phases; (Since there are two parts of chlorobenzene phase, this step is repeated twice); S3.2, using the chlorobenzene discharge interface meter and U-bend, the lower chlorobenzene solvent is separated into the waste chlorobenzene tank; the upper aqueous phase is retained in the alkali dissolving kettle, waiting for petroleum ether to be added for extraction; after the chlorobenzene phase in the kettle is discharged, the chlorobenzene in the discharge pipeline is discharged cleanly by using the U-bend bypass valve; S3.3, about 400 kg of petroleum ether (measured by flow meter and interlocked and closed) flowing out of the petroleum ether metering tank is added into the alkali dissolving kettle, stirred for 0.5 h, and allowed to stand for 1 h; using the alkali water discharge interface meter and U-bend, the lower aqueous phase is discharged into the acid precipitation kettle for acid precipitation; The upper petroleum ether washing liquid is discharged into the petroleum ether washing liquid tank and can be directly reused or reused after distillation and impurity removal; after the alkaline water phase in the alkali dissolving kettle is discharged, the alkaline water in the discharge pipeline is discharged cleanly with a U-bend bypass valve; Acid precipitation includes the following steps: S4.1. After all the aqueous phase in the alkali dissolution kettle is transferred to the acid precipitation kettle, start stirring and use a flow meter to control the dilute hydrochloric acid in the dilute hydrochloric acid head tank to drip into the acid precipitation kettle at a rate of 300kg / h; when the amount of dilute hydrochloric acid in the dilute hydrochloric acid head tank is about 90%, take samples at intervals to analyze the pH value of the feed liquid in the acid precipitation kettle, and controlling the pH to 3-4 indicates that the dripping is completed; the total dripping time is 4h; Filter pressing and dehydration include the following steps: S5.1. Turn on the keto acid filter press pump to pump the material in the acid precipitation kettle into the acid-acid filter press. After the material in the acid precipitation kettle is pumped, filter press the material with the filter press. When the filter press is finished, release the pressure and open the plate to discharge the material. S5.2. Put about 3.5 tons of filter residue from the filter press through the manhole of the ketoacid dehydration kettle, close the manhole, start the jacket steam to start heating (do not start the stirring of the kettle first), and at the same time start the jacket circulating water of the acid dehydration condenser; When the temperature in the keto acid dehydration kettle rises to 150°C and all the materials are melted, start stirring, then start the vacuum pump, reduce the pressure in the keto acid dehydration kettle to -0.07MPa, and dry under reduced pressure for 3 hours; stop stirring the keto acid dehydration kettle, eliminate the vacuum in the kettle, take the keto acid sample from the discharge valve at the bottom of the kettle, and test the water content in the sample to ≤0.5%; if the water content is too high, continue to dry under reduced pressure; After the keto acid dehydration kettle is dried, the vacuum is eliminated and the temperature is maintained at 150°C for standby use; Chlorobenzene drying includes the following steps: S6.1, waste chlorobenzene pump with 1m 3 / h flow rate, the chlorobenzene in the waste chlorine tank is sent to the chlorobenzene coalescer to separate the possible entrained water, and then dried in the chlorobenzene dryer and stored in the dry chlorobenzene tank for standby use; S6.2. When the chlorobenzene coalescer is used for the first time, when the equipment is U-bend discharging, slightly open the upper drain valve to discharge the air in the equipment; when the liquid level gauge is full, close the drain valve to complete the exhaust; The chlorobenzene dryer is drained once, and the sewage is discharged to the ditch and then flows into the underground pool in the south. When the equipment is draining sewage, carefully observe the sewage sight glass and be careful not to discharge chlorobenzene outside the equipment; Chlorobenzene distillation includes the following steps: S7.1. When the chlorobenzene in the dry chlorobenzene tank has been recycled twice, or the benzene content is ≥6%, use a dry chlorobenzene pump and flowmeter to measure about 6 tons of chlorobenzene into the chlorobenzene distillation kettle; or the solution in the chlorobenzene front fraction tank is directly discharged into the chlorobenzene distillation kettle; Close all valves of the chlorobenzene distillation kettle, close the vacuum buffer tank valve of the vacuum pump, open the N2 inlet valve, and pass N2 into the kettle. When the pressure reaches 0.05MPa, close the N2 valve and open the vent valve to release the pressure to normal pressure. Perform N2 replacement in the kettle twice in total; Turn on the circulating water and chilled water in the jacket of the condenser at the top of the distillation tower, start stirring in the kettle, turn on the vacuum pump to evacuate to -0.085MPa, and raise the temperature at the same time; When the temperature in the chlorobenzene distillation kettle rises to 100℃, open the outlet of the condenser at the top of the distillation tower and observe the condensate in the cup, and control the condensate to ≤40℃; when the liquid level in the chlorobenzene gas-liquid separation tank is 50%, open the chlorobenzene reflux pump and the condensate will fully reflux to the top of the distillation tower; adjust the flow rate of the chlorobenzene reflux pump to 1m 3 / h, so that the liquid level in the chlorobenzene gas-liquid separation tank remains stable; maintain the full reflux state for 3h; Adjust the flow meter to control the reflux ratio to 5:1, and take out the front fraction to the chlorobenzene front fraction tank; 3 hours after the fore fraction was extracted, instantaneous samples were taken from the outlet of the chlorobenzene reflux pump for inspection (every 2 hours / time) until the chlorobenzene content in the sample was ≥97%, then the state of full extraction (reflux volume was 0) was adjusted, and the extracted liquid was switched to the distillation chlorobenzene tank; Maintain the vacuum degree of the chlorobenzene distillation kettle at -0.095MPa, slowly increase the distillation temperature, and maintain stable distillation; When the temperature of the liquid in the chlorobenzene distillation kettle reaches 130℃, the temperature at the top of the distillation tower begins to drop, and there is no condensate in the sight glass at the outlet of the condenser at the top of the distillation tower, it indicates that the distillation is finished; Stop the chlorobenzene reflux pump, stop the vacuum pump, turn off the jacket steam of the chlorobenzene distillation kettle, and start cooling; open the N2 inlet valve to eliminate the vacuum in the kettle; when the distillation residual liquid in the kettle is cooled to ≤100℃, discharge it into the chlorobenzene residual liquid tank; discharge the condensate in the chlorobenzene gas-liquid separation tank into the distillation chlorobenzene tank; Petroleum ether distillation When the chlorobenzene content in the petroleum ether washing liquid in the petroleum ether washing liquid tank is ≥30%, use the petroleum ether washing liquid pump and flow meter to measure 4.2 tons of washing liquid and pump it into the petroleum ether distillation kettle; close all valves of the petroleum ether distillation kettle, close the vacuum buffer tank valve of the vacuum pump, open the N2 inlet valve, and pass N2 into the kettle. When the pressure is 0.05MPa, close the N2 valve and open the vent valve to release the pressure to normal pressure; perform N2 replacement in the kettle twice in total; Start stirring the petroleum ether distillation kettle, turn on the circulating water and chilled water in the jacket of the condenser at the top of the distillation tower, do not start stirring the petroleum ether distillation kettle first, turn on the vacuum pump and evacuate to -0.085MPa, and raise the temperature at the same time; when the temperature in the petroleum ether distillation kettle rises to 80℃, when there is condensate at the outlet of the condenser at the top of the distillation tower, control the condensate to ≤40℃; when the liquid level in the chlorobenzene gas-liquid separation tank is 50%, turn on the chlorobenzene reflux pump, and the condensate will fully reflux to the top of the distillation tower; adjust the flow rate of the chlorobenzene reflux pump (1m 3 / h) to keep the liquid level in the chlorobenzene gas-liquid separation tank stable; maintain the full reflux state for 3h; Adjust the flow meter to control the reflux ratio to 3:1, and the front fraction (i.e. petroleum ether) flows to the petroleum ether washing liquid recovery tank; slowly increase the distillation temperature of the petroleum ether distillation kettle to ensure smooth distillation; Take an instantaneous sample from the outlet of the chlorobenzene reflux pump to analyze the chlorobenzene content in the current fraction. When the chlorobenzene content is ≥10%, switch the fraction to the chlorobenzene residual liquid tank, and adjust the flow meter to control the reflux ratio to 5:1; when the chlorobenzene content in the fraction is ≥97%, adjust it to the full extraction state (reflux volume is 0), and switch the fraction to the distillation chlorobenzene tank; Keep the vacuum degree of chlorobenzene distillation kettle at -0.095MPa, slowly increase the distillation temperature, and maintain stable distillation; when the liquid temperature in the petroleum ether distillation kettle reaches 130℃, the temperature at the top of the distillation tower begins to drop, and there is no condensate in the sight glass at the outlet of the condenser at the top of the distillation tower, it indicates that the distillation is finished; Stop the chlorobenzene reflux pump, stop the vacuum pump, turn off the jacket steam of the petroleum ether distillation kettle, and start cooling; open the N2 inlet valve to eliminate the vacuum in the kettle; when the distillation residual liquid in the kettle is cooled to ≤100℃, discharge it into the chlorobenzene residual liquid tank; the condensate in the chlorobenzene gas-liquid separation tank is discharged into the distillation chlorobenzene tank.

[0053] The operating precautions in this application are as follows: Control the water content of chlorobenzene and tert-amylbenzene to meet the requirements.

[0054] When feeding the ketoacid reactors A to F, the addition acceleration of tert-amylbenzene and aluminum chloride and the N2 flow rate are controlled steadily, and the addition temperature is 0 to 2°C; when the temperature of the solution in the reactor is greater than 2°C, the addition of tert-amylbenzene and aluminum chloride can be suspended. The venting pipelines of the ketoacid reactors A to F are unobstructed, without backlog or accumulation of materials; the tail gas absorption tower T502 / 503 is not blocked.

[0055] The feeding hole on the top of the aluminum chloride feeding tank is tightly sealed to prevent air leakage.

[0056] Control the feeding speed of the keto acid hydrolysis kettle to control the acid hydrolysis temperature at 80-85℃ to prevent material rushing; when the temperature is greater than 85℃, the feeding can be suspended and the feeding can be resumed after the temperature drops to ≤75℃; when discharging the aluminum chloride solution, pay attention to the oil-water interface to prevent the oil phase from being discharged by mistake.

[0057] When the ketoacid acidolysis kettle is discharging the chlorobenzene phase, the ketoacid chlorobenzene solution delivery pump should stop the pump 10 to 15 seconds after the water phase appears in the inlet long sight glass to ensure that there is no chlorobenzene phase in the pipeline.

[0058] Before the jacket of the ketoacid hydrolysis reactor is switched to steam, the circulating water in the jacket must be removed.

[0059] The acylation reaction liquid (chlorobenzene phase) in the ketoacid reaction liquid tank needs to be divided into two times and enter the alkaline dissolution kettle for alkaline dissolution treatment.

[0060] The acid precipitation kettle should be dripped with dilute hydrochloric acid solution steadily; when the pH value of the solution in the kettle is 3-4, stop dripping, and do not add too much. Ketoacid dehydration kettle When dehydrating the ketoacid in the kettle, first raise the temperature to 140-150℃, wait until the ketoacid in the kettle is completely melted, and then evacuate; after drying, the water content of the ketoacid is ≤0.5%. If the water content is too high, extend the drying time; after vacuum drying, maintain the temperature and do not let the ketoacid in the kettle solidify.

[0061] When distilling chlorobenzene or petroleum ether, the distillation pressure and temperature should be adjusted steadily, and samples should be taken in time to analyze the content of the distillate. When eliminating the vacuum in the chlorobenzene distillation kettle or petroleum ether distillation kettle, N2 should be used.

[0062] When draining the upper part of the chlorobenzene coalescer, be careful not to discharge chlorobenzene.

[0063] The water content of chlorobenzene at the outlet of chlorobenzene dryer is ≤0.05%; when the water content is greater than 0.05%, find out the cause in time or replace the desiccant.

[0064] Possible abnormal situations and their treatment measures If the keto acid hydrolysis kettle is overcharged, stop feeding immediately and resume feeding after the temperature drops to ≤75℃.

[0065] When distilling in chlorobenzene distillation kettle or petroleum ether distillation kettle, if no liquid is distilled out of the sight glass at the condenser outlet, focus on checking the distillation pressure, temperature, condenser outlet temperature, etc.

[0066] If the keto acid in the keto acid dehydration kettle solidifies, just open the jacket steam and reheat it to melt it. If the tail gas absorption tower is blocked, clear the blockage in the tower in time.

[0067] Result analysis: By comparing the separation process of chlorobenzene and keto acid solution provided in combination with Examples 1 to 3 and Comparative Example 1, it can be seen that: the present application can efficiently separate chlorobenzene and keto acid through the precisely controlled washing and distillation steps, significantly improve the separation efficiency, and reduce the time and resources required for separation compared to the traditional process. By adopting optimized heating and distillation conditions, the separation task can be completed at a lower energy consumption, reducing energy consumption, reducing production costs, and reducing greenhouse gas emissions, which meets the requirements of green production. The use of flammable and toxic organic solvents such as petroleum ether is avoided, the potential pollution to the environment is reduced, the generation of wastewater is reduced, the wastewater treatment process is simplified, and the environmental protection cost is reduced. The potential safety hazards such as fire and explosion in the traditional process are removed, and a safer production environment is created through safe washing and distillation operations, protecting the health and safety of operators. In addition, the present process attaches importance to the rational use of water resources, reduces the discharge of harmful wastewater, and recycles the hydrolysis water after cooling, which reflects the friendly attitude towards the environment and the concept of sustainable development, which is in line with the current development trend of green chemical industry. Combined with the above-mentioned technical effects, the separation process of the present invention shows significant cost-effectiveness in reducing energy consumption, reducing waste treatment costs, and improving product purity, providing enterprises with a more competitive production process.

[0068] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A process for separating chlorobenzene and ketoacid solution, characterized in that: The chlorobenzene and keto acid solution separation process comprises the following steps: S1, primary water washing; S2, secondary water washing; S3, chlorobenzene distillation; S4, chlorobenzene drying; A water wash includes the following steps: S1.1, add hot water from the acylation hot water pump to the acylation hot water reactor containing chlorobenzene and keto acid solution, and interlock and close the acylation hot water pump and the acylation hot water reactor valve; S1.2, the jacket system of the acylation hot water reactor is switched to steam heating mode, the temperature is raised to 80-85°C, water washing is performed and the reactor is allowed to stand to separate the materials into chlorobenzene phase and water phase; S1.3, after stratification, the lower chlorobenzene phase is transferred to the ketoacid reaction liquid tank through a centrifugal pump, and the upper aqueous phase is discharged to the acylation washing water tank; S1.4, drain the circulating water of the acylation hot water reactor and prepare for the next step; The secondary washing process includes the following steps: S2.1, returning the chlorobenzene phase collected in the ketoacid reaction tank in step S1.3 to the acylation hot water reactor, adding hot water from the acylation hot water pump, and interlocking and closing the acylation hot water pump and the acylation hot water reactor valve; S2.2, the jacket system of the acylation hot water reactor is switched to the steam heating mode, the temperature is raised to 80-85°C, and water washing is performed and allowed to stand to cause the material to be separated into a chlorobenzene phase and a water phase; S2.3, after stratification, the lower chlorobenzene phase is transferred to the ketoacid reaction liquid tank through a centrifugal pump, and the upper aqueous phase is discharged to the acylation washing water tank; Chlorobenzene distillation includes the following steps: S3.1, open the condenser of the chlorobenzene still kettle to preheat the chlorobenzene still kettle, then transfer the chlorobenzene phase in the ketoacid reaction liquid tank to the chlorobenzene still kettle through the ketoacid chlorobenzene solution delivery pump, turn on the jacket steam heating of the chlorobenzene still kettle, and start distillation; and add hot water to the chlorobenzene still kettle for atmospheric distillation, so that chlorobenzene is collected in the waste chlorobenzene pump, and when no chlorobenzene is evaporated, close the jacket steam valve of the chlorobenzene still kettle, let it stand for 5-10 minutes, after the materials are separated, discharge the lower layer of ketoacid molten liquid into the dehydration kettle, and then discharge the upper layer of acidic waste water into the collection tank, and use it as hydrolysis water after cooling; Chlorobenzene drying includes the following steps: S4.

1. Transfer the chlorobenzene collected by the waste chlorobenzene pump to the chlorobenzene agglomerator for preliminary dehydration and drying.

2. A process for separating chlorobenzene and ketoacid solution according to claim 1, characterized in that: The water washing treatment time in step S1.2 is 0.5-1.5 hours, and the resting time is 0.5-1 hour.

3. A process for separating chlorobenzene and ketoacid solution according to claim 1, characterized in that: The water washing time in step S2.2 is 0.5-1.5 hours, and the resting time is 0.5-1 hour.

4. A process for separating chlorobenzene and ketoacid solution according to claim 1, characterized in that: The distillation temperature of the steam heating distillation in step S3.1 is 90-105° C. and the time is 30 minutes.

5. A process for separating chlorobenzene and ketoacid solution according to claim 1, characterized in that: The time for standing and separating the materials in step S3.1 is 5-10 minutes.

6. A process for separating chlorobenzene and ketoacid solution according to claim 1, characterized in that: The flow rate of transferring chlorobenzene to the chlorobenzene coalescer in step S4.1 is 1 m³ / h.

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