A continuous separation system and method for liquid aniline derivative intermediates

Abstract

The application discloses a continuous separation system and method for liquid aniline derivative intermediates, and the liquid aniline derivative intermediates are liquid 3-(N,N-diallyl) amino-4-methoxy acetanilide or liquid 3-(N,N-diethyl) amino acetanilide. The application can quickly separate product heavy oil, mother liquor water and floating oil components by using a continuous oil-water separator, a floating oil intermediate tank and a product oil intermediate tank. The emulsified materials in the mother liquor water can be effectively recovered by using the mother liquor intermediate tank for salting-out demulsification. The separated mother liquor clear liquid enters an MVR evaporation system, and ammonium chloride salt and distilled water are obtained through evaporation, concentration and crystallization. The ammonium chloride concentrate can be recycled for salting-out demulsification. After the liquid aniline derivative intermediate crude product is subjected to the continuous separation system and method, the separation efficiency of the liquid material is high, the overall material yield is improved, the solid content of the product is obviously improved, the system stability is good, and the wastewater treatment cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of separation technology for liquid aniline derivative intermediates, and specifically to a continuous separation system and method for liquid aniline derivative intermediates, wherein the liquid aniline derivative intermediate is liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide. Background Technology

[0002] Aniline derivatives are important intermediates required for dye synthesis, and different aniline derivatives can be used to synthesize corresponding or multiple dye varieties. Aniline derivatives are diverse, and commonly used aniline derivatives in dye synthesis include 3-(N,N-diallyl)amino-4-methoxyacetanilide (hereinafter referred to as "diallyl") and 3-(N,N-diethyl)aminoacetanilide (hereinafter referred to as "m-diethyl"). The preparation of aniline derivative intermediates involves both solid and liquid products. Solid products undergo cooling, crystallization, washing, and pressure filtration during production, a cumbersome process. Cooling and washing consume large amounts of water, increasing production costs. Furthermore, manual feeding is labor-intensive for subsequent dye synthesis, which is not in line with the current continuous dye production practices. The preparation of liquid aniline derivative intermediates involves separation methods such as static layering and continuous overflow layering. However, because different liquid aniline derivative intermediates exist in different states in the mother liquor after synthesis, the above separation methods may result in incomplete separation and water or material carried over to the effluent.

[0003] 3-(N,N-diallyl)amino-4-methoxyacetanilide and 3-(N,N-diethyl)aminoacetanilide are important fine chemical intermediates used in the synthesis of dyes such as the 291 Disperse Blue series, 93:1 Disperse Violet, and 79:1 Disperse Blue, and are in high market demand. Diallyl and m-diethyl exist in oily form during synthesis and are insoluble in water. When used in batch or continuous dye synthesis processes, they are primarily present as liquid products.

[0004] Liquid diallyl and m-diethyl crude products are separated from the mother liquor through stratification to obtain liquid diallyl and m-diethyl. The separated liquid products can be stored in a storage tank under temperature preservation or directly used in subsequent dye synthesis pulping processes. No manual feeding is required during dye synthesis, and the synthesized dye products have been verified to meet the required specifications. Therefore, the separation of the products from the mother liquor is a crucial step in the preparation of liquid diallyl and m-diethyl.

[0005] The conventional separation and preparation of liquid diallyl and m-diethyl involves feeding the qualified crude diallyl or m-diethyl product into a separatory vessel, where it is allowed to stand and separate into oil and water phases. However, during this separation process, the crude diallyl or m-diethyl product presents a layer of floating oil / mother liquor / heavy oil, with a heavy oil layer at the bottom, a floating oil layer at the top, and an aqueous mother liquor in between. The aqueous mother liquor contains a small amount of product (or emulsified material) due to emulsification and cannot be recovered through simple separation. In this situation, standing separation is incomplete, requiring further processing of the separated mother liquor (containing a small amount of floating oil and emulsified material), making the process cumbersome. Furthermore, standing separation inevitably leads to water carryover in the product effluent and water carryover in the mother liquor effluent. Additionally, standing separation results in unstable solids content, ranging from 50% to 70%, significantly impacting the feed ratio of downstream processes.

[0006] Patent specification CN111153828A discloses a method for separating crude diallyl product using a continuous overflow separation process. The crude product, after passing the reaction, is fed into a separation vessel; the upper wastewater is treated in an MVR system; and the lower product is washed with hot water in a washing vessel to obtain the final product. This method achieves good separation and washing results. However, the separation problems of floating oil and small amounts of emulsified products in the aqueous phase of the synthesized diallyl crude product remain unresolved. Furthermore, water washing easily leads to water carryover in the effluent and water carryover in the effluent, affecting the solids content of the product. Additionally, further water washing increases water consumption and wastewater treatment costs. The same issues exist when using continuous overflow separation to separate crude m-diethyl.

[0007] Regarding the treatment of emulsified oil in mother liquor, the patent specification with announcement number CN214551364U discloses an oil-water intermediate layer separation device that uses a third phase trap and internal plate membrane modules to filter and separate the emulsified oil phase. However, due to the characteristics of the oil phase itself, the separation of the emulsified oil phase in the mother liquor cannot be completely guaranteed before and after filtration. At the same time, the concentrated emulsified oil returns to the front end and re-enters the system, which will cause the emulsified oil content in the mother liquor to increase, making it impossible to effectively recover it.

[0008] Therefore, based on the characteristics of liquid diallyl and liquid meta-diethyl materials and the problem of separating floating oil and emulsified oil phase in crude mother liquor, the present invention provides a method and system for continuous separation of liquid diallyl or liquid meta-diethyl. Summary of the Invention

[0009] This invention provides a continuous separation system and method for liquid aniline derivative intermediates, wherein the liquid aniline derivative intermediate is liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or 3-(N,N-diethyl)aminoacetanilide. Based on the different densities of the floating oil, mother liquor water, and heavy oil in the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or 3-(N,N-diethyl)aminoacetanilide, the continuous separation system and method of this invention can achieve rapid oil-water separation of the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or 3-(N,N-diethyl)aminoacetanilide. The lower layer of product oil (or heavy oil) after separation is stored in a finished product oil storage tank after passing through a product oil intermediate tank, and the upper layer of floating oil is concentrated in a floating oil intermediate tank and also stored in a finished product oil storage tank. The aqueous phase of the mother liquor and the ammonium chloride concentrate enter the intermediate mother liquor tank. After salting out and demulsification, the upper layer of floating oil (the material after salting out and demulsification) is stored in the finished oil storage tank. The clarified mother liquor effluent enters the MVR evaporation system, where it is evaporated, concentrated, and crystallized to obtain ammonium chloride salt and distilled water. Part of the ammonium chloride concentrate is recycled back to the intermediate mother liquor tank for salting out and demulsification. This invention improves production efficiency, increases and stabilizes the solids content of the product, effectively recovers emulsified materials and floating oil from the mother liquor, and allows for the recycling of ammonium chloride in the mother liquor, reducing wastewater treatment costs.

[0010] A continuous separation system for liquid aniline derivative intermediates, wherein the liquid aniline derivative intermediate is liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide, and the continuous separation system for the liquid aniline derivative intermediates comprises:

[0011] A continuous oil-water separator is used to separate the upper layer of floating oil, the lower layer of product oil, and the middle layer of mother liquor aqueous phase from liquid crude 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide.

[0012] The intermediate oil tank is used to receive the upper layer of floating oil separated by the continuous oil-water separator and further separate the mother liquor aqueous phase from the upper layer of floating oil.

[0013] The intermediate product oil tank is used to receive the lower layer product oil separated by the continuous oil-water separator and further separate the mother liquor aqueous phase from the lower layer product oil.

[0014] The intermediate mother liquor tank is used to receive the intermediate layer mother liquor aqueous phase separated by the continuous oil-water separator, the lower layer mother liquor aqueous phase separated by the floating oil intermediate tank, and the upper layer mother liquor aqueous phase separated by the product oil intermediate tank. Salting out and demulsification form the upper layer floating oil and the lower layer mother liquor clear liquid.

[0015] The finished oil storage tank is used to receive the floating oil after the mother liquor aqueous phase is separated from the floating oil intermediate tank, the product oil after the mother liquor aqueous phase is separated from the product oil intermediate tank, and the upper floating oil formed after salting out and demulsifying the mother liquor intermediate tank.

[0016] The MVR evaporation system is used to receive and process the lower layer of mother liquor from the intermediate mother liquor tank. The lower layer of mother liquor enters the MVR evaporation system and is evaporated, concentrated, and crystallized to obtain ammonium chloride salt and distilled water. At the same time, part of the ammonium chloride concentrate is returned to the intermediate mother liquor tank for salting out and demulsification.

[0017] The continuous separation system for the liquid aniline derivative intermediate may also include an ammonium chloride concentrate buffer tank.

[0018] The ammonium chloride concentrate buffer tank is used to receive and store the ammonium chloride concentrate produced by the MVR evaporation system, and to supply the ammonium chloride concentrate to the mother liquor intermediate tank for salting out and demulsification.

[0019] The intermediate mother liquor tank is connected to a continuous oil-water separator, a floating oil intermediate tank, and a product oil intermediate tank. The lower layer of clarified mother liquor outlet in the intermediate mother liquor tank can be connected to the MVR evaporation system via a clarified liquid pump. The MVR evaporation system can be connected to an ammonium chloride concentrate buffer tank, which can be connected to the intermediate mother liquor tank via an ammonium chloride concentrate transfer pump.

[0020] The continuous separation system for the liquid aniline derivative intermediate may also include a raw material buffer tank and a filter; the raw material buffer tank, the filter, and the continuous oil-water separator are connected in sequence.

[0021] The raw material buffer tank is used to store and mix liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid crude 3-(N,N-diethyl)aminoacetanilide.

[0022] The temperature of the raw material buffer tank can be controlled between 80 and 95°C, preferably between 80 and 88°C. If the tank insulation temperature is too low, the viscosity of the material will increase, which is not conducive to the mixing of the material; if the tank insulation temperature is too high, some of the heavy oil in the raw material buffer tank will float to the surface and form floating oil, which will affect the oil-water separation effect.

[0023] In one embodiment, a first upper valve connected to a floating oil intermediate tank is provided near the top of the continuous oil-water separator, and a first density meter is provided at the top of the continuous oil-water separator for feeding back the density of the upper floating oil in the continuous oil-water separator. The first density meter and the first upper valve form a density interlock to control the discharge of the upper floating oil in the continuous oil-water separator into the floating oil intermediate tank.

[0024] A first central valve connected to the mother liquor intermediate tank is provided in the middle of the continuous oil-water separator, and a first lower valve connected to the product oil intermediate tank is provided near the bottom of the continuous oil-water separator. A conductivity meter is installed inside the continuous oil-water separator between the first central valve and the first lower valve. The conductivity meter is interlocked with the first central valve and the first lower valve. The opening of the first central valve and the first lower valve is adjusted according to the change in conductivity to control the discharge of the intermediate layer mother liquor aqueous phase and the lower layer product oil from the continuous oil-water separator into the mother liquor intermediate tank and the product oil intermediate tank.

[0025] In one embodiment, a second upper valve connected to a finished oil storage tank is provided near the top of the floating oil intermediate tank, and a second lower valve connected to a mother liquor intermediate tank is provided near the bottom of the floating oil intermediate tank. A second density meter for feeding back the density of the upper layer of floating oil in the floating oil intermediate tank is provided at the top of the floating oil intermediate tank. The second density meter, together with the second upper valve and the second lower valve, or separately with the second lower valve, forms a density interlock to control the discharge of the upper layer of floating oil and the lower layer of mother liquor aqueous phase in the floating oil intermediate tank into the finished oil storage tank and the mother liquor intermediate tank.

[0026] In one embodiment, a third upper valve connected to a mother liquor intermediate tank is provided near the top of the product oil intermediate tank, and a third lower valve connected to a finished oil storage tank is provided near the bottom of the product oil intermediate tank. A third density meter for feeding back the density of the lower layer of product oil in the product oil intermediate tank is provided at the top of the product oil intermediate tank. The third density meter, together with the third upper valve and the third lower valve, or alone with the third upper valve, forms a density interlock to control the discharge of the upper layer of mother liquor aqueous phase and the lower layer of product oil in the product oil intermediate tank into the mother liquor intermediate tank and the finished oil storage tank.

[0027] In one embodiment, a fourth upper valve connected to the finished oil storage tank is provided near the top of the intermediate mother liquor tank, and a second middle valve connected to the MVR evaporation system is provided in the middle of the intermediate mother liquor tank. A fourth density meter for feeding back the density of the upper floating oil in the intermediate mother liquor tank is provided at the top of the intermediate mother liquor tank. The fourth density meter and the fourth upper valve form a density interlock to control the discharge of the upper floating oil after salt precipitation and demulsification in the intermediate mother liquor tank into the finished oil storage tank.

[0028] A fourth bottom valve, connecting to the continuous oil-water separator, the floating oil intermediate tank, and the product oil intermediate tank, can be installed near the bottom of the mother liquor intermediate tank. A fifth bottom valve, connecting to the ammonium chloride concentrate transfer pump, can be installed at the bottom of the mother liquor intermediate tank 6.

[0029] In one embodiment, a fifth upper valve connected to the MVR evaporation system is provided near the top of the ammonium chloride concentrate buffer tank, a sixth lower valve connected to the ammonium chloride concentrate transfer pump is provided at the bottom of the ammonium chloride concentrate buffer tank, and a fifth densitometer is provided in the middle of the ammonium chloride concentrate buffer tank. The fifth densitometer is used to monitor the density of the ammonium chloride concentrate in the ammonium chloride concentrate buffer tank in real time.

[0030] In the continuous separation system for the liquid aniline derivative intermediate, the insulation medium for pipes, vessels, etc., can be one or both of low-pressure steam and hot water.

[0031] A continuous separation method for liquid aniline derivative intermediates, wherein the liquid aniline derivative intermediate is liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide, and the method employs the continuous separation system for the liquid aniline derivative intermediates.

[0032] The continuous separation method for the liquid aniline derivative intermediate includes:

[0033] A continuous oil-water separator is used to separate the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide into an upper floating oil layer, a lower product oil layer, and an intermediate mother liquor aqueous phase.

[0034] The floating oil intermediate tank is used to receive the upper layer of floating oil separated by the continuous oil-water separator and further separate the mother liquor aqueous phase from the upper layer of floating oil;

[0035] The intermediate tank for product oil receives the lower layer of product oil separated by a continuous oil-water separator and further separates the mother liquor aqueous phase from the lower layer of product oil.

[0036] The intermediate mother liquor tank is used to receive the intermediate layer mother liquor aqueous phase separated by the continuous oil-water separator, the lower layer mother liquor aqueous phase separated by the floating oil intermediate tank, and the upper layer mother liquor aqueous phase separated by the product oil intermediate tank. Salting out and demulsifying are then performed to form the upper layer floating oil and the lower layer mother liquor clear liquid.

[0037] The finished oil storage tank is used to receive the floating oil after the mother liquor aqueous phase is separated in the intermediate tank, the product oil after the mother liquor aqueous phase is separated in the intermediate tank, and the upper floating oil formed after salting out and demulsifying the mother liquor in the intermediate tank.

[0038] The MVR evaporation system is used to receive and process the lower layer of mother liquor from the intermediate mother liquor tank. The lower layer of mother liquor enters the MVR evaporation system and is evaporated, concentrated, and crystallized to obtain ammonium chloride salt and distilled water. At the same time, part of the ammonium chloride concentrate is returned to the intermediate mother liquor tank for salting out and demulsification.

[0039] The continuous separation method for the liquid aniline derivative intermediate may further include receiving and storing the ammonium chloride concentrate generated by the MVR evaporation system in an ammonium chloride concentrate buffer tank and supplying the ammonium chloride concentrate to a mother liquor intermediate tank for salting out and demulsification.

[0040] The crude oil content of the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide can be 15wt% to 40wt%, preferably 20wt% to 35wt%. If the crude oil content is too low, continuous discharge will lead to water carryover at the bottom of the continuous oil-water separator; if the crude oil content is too high, i.e., the water content of the mother liquor is reduced, the density of the mother liquor will be greater than the density of the liquid diallyl or liquid meta-diethyl, causing the heavy oil in the product in the continuous oil-water separator to float to the top, disrupting the internal steady-state balance of the continuous oil-water separator, thereby causing water carryover at the outlet and water carryover at the outlet.

[0041] The purity of the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide is preferably not less than 95%, as too low a purity is not conducive to subsequent dye synthesis processes.

[0042] The salt content of the crude mother liquor of liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide can be 10wt% to 25wt%, preferably 15wt% to 20wt%. If the salt content of the mother liquor is too high, the bottom water from the upstream diallyl or meta-diethyl synthesis reaction is reduced, resulting in the density of the aqueous phase of the crude mother liquor being greater than the density of the liquid diallyl or liquid meta-diethyl. This causes the heavy oil components in the product to float to the surface, disrupting the internal steady state of the continuous oil-water separator. This leads to severe water carryover in the intermediate layer of the mother liquor aqueous phase, while the bottom product oil also carries water, affecting the solids content of the liquid product.

[0043] The solid content of the material in the finished oil storage tank can be greater than 85 wt%. The liquid material in the finished oil storage tank mainly comes from the upper layer of floating oil in the intermediate oil tank, the lower layer of heavy oil in the intermediate product oil tank, and the upper layer of floating oil in the intermediate mother liquor tank. These three liquid materials will carry some mother liquor water, which contains ammonium chloride salts, easily causing the salt content of the liquid material in the finished oil storage tank to increase, affecting the amount of feed for subsequent dye synthesis. To avoid this situation, the solid content of the material in the finished oil storage tank is preferably greater than 90 wt%. The solid content is obtained by drying analysis. During drying, the moisture is removed at a constant temperature. After the material is dried to constant weight (completely removing moisture), the weight of the dried material is divided by the weight of the material before drying and multiplied by 100% to obtain the solid content of liquid diallyl or liquid meta-diethyl.

[0044] The ratio of the volumetric flow rate of the lower layer product oil to the volumetric flow rate of the middle layer mother liquor water phase in the continuous oil-water separator can be set according to the oil-water ratio (oil content) in the liquid diallyl or liquid meta-diethyl crude product. For example, it can be controlled at 1:1.5 to 1:5 (which is suitable for an oil content of 15wt% to 40wt%), preferably at 1:1.85 to 1:4 (which is suitable for an oil content of 20wt% to 35wt%), in order to avoid water carryover in the bottom heavy oil discharge of the continuous oil-water separator and water carryover in the middle mother liquor discharge.

[0045] The conductivity of the lower layer product oil separated by the continuous oil-water separator is preferably 500-5000 μS / cm, and more preferably 500-2000 μS / cm. If the conductivity is too high, the lower layer product oil level will be low, and continuous discharge will cause water to be carried over to the bottom of the continuous oil-water separator; if the conductivity is too low, the lower layer product oil level will be high, and continuous discharge will cause water to be carried over to the continuous oil-water separator.

[0046] The temperatures of the continuous oil-water separator, intermediate product oil tank, and finished product oil storage tank are preferably controlled between 80 and 95°C, and further preferably between 80 and 88°C. If the tank insulation temperature is too low, the viscosity of the material increases, increasing the risk of pipeline blockage; if the tank insulation temperature is too high, some heavy oil will float to the surface, forming sludge and affecting the oil-water separation effect. In addition, prolonged high temperatures in the finished product oil storage tank will affect the quality of the liquid product.

[0047] At higher temperatures, the floating oil and mother liquor in the crude product exhibit good stratification. To further enhance the oil-water stratification effect in the intermediate oil tank, the temperature of the intermediate oil tank is preferably controlled at 85–95℃, and more preferably at 88–93℃. To ensure the salting-out and demulsification effect of the emulsified materials in the mother liquor and the stratification effect between the mother liquor and the floating oil (formed after the demulsification of the emulsified materials) after salting-out and demulsification, the temperatures of the intermediate mother liquor tank and the ammonium chloride concentrate buffer tank are preferably controlled at 85–95℃, and more preferably at 88–93℃.

[0048] The density of the upper layer of floating oil in the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide crude product and the upper layer of floating oil in the intermediate tank of the mother liquor is preferably 1005-1020 kg / m³. 3 The water density of the mother liquor in the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide crude product is preferably 1025-1038 kg / m³. 3 The product oil density in the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide crude product is preferably 1040-1050 kg / m³. 3When the density meters of the continuous oil-water separator, floating oil intermediate tank, product oil intermediate tank, and mother liquor intermediate tank change from the density of the mother liquor aqueous phase to the density of the floating oil or heavy oil, or from the density of the floating oil or heavy oil to the density of the mother liquor aqueous phase, the density interlock opens or closes the corresponding valve. To avoid water carrying over material or material carrying over to the outlet, and to control the solid content of the product, the density of the upper floating oil (including the upper floating oil in the mother liquor intermediate tank) is further preferably 10¹⁰~10¹⁸ kg / m³. 3 The water density of the mother liquor is further preferably 1025-1035 kg / m³. 3 The density of the lower layer heavy oil (product oil) is further preferably 1042-1048 kg / m³. 3 The optimized density is used as density interlocking data.

[0049] The density of ammonium chloride concentrate in the ammonium chloride concentrate buffer tank is preferably controlled at 1080-1100 kg / m³. 3 To ensure a significant demulsification effect through salting out, the density of the ammonium chloride concentrate was further optimized and controlled at 1090-1100 kg / m³. 3 .

[0050] The density of the lower layer of clear mother liquor formed by salting out and demulsifying in the intermediate tank can be adjusted by regulating the feed rate of the ammonium chloride concentrate, preferably controlled at 1055–1070 kg / m³. 3 .

[0051] This invention, based on the characteristics of diallyl or m-diethyl materials, addresses the problems associated with static stratification and continuous overflow separation methods by providing a continuous oil-water separation system and method. This system utilizes continuous oil-water separation technology to separate crude diallyl or m-diethyl products into liquid products. The continuous separation system can be automatically controlled using DCS (Distributed Control System) logic interlocks, requiring minimal manual intervention during operation. Compared to static stratification and continuous overflow separation methods, it shortens material separation time, improves production efficiency, significantly increases and stabilizes the solids content of the material, and effectively recovers small amounts of floating oil and emulsified materials from the crude product, thus improving material yield. Furthermore, the continuous separation system and method for liquid diallyl or liquid m-diethyl can be configured with different processing flow rates according to downstream requirements, greatly satisfying production needs, while maintaining the purity of the separated liquid diallyl and liquid m-diethyl. The liquid product from this process does not require water washing and can be directly used in subsequent processes. The separated mother liquor is recycled into the MVR evaporation system to obtain ammonium chloride and distilled water. Simultaneously, the concentrated ammonium chloride solution can be recycled for mother liquor salting-out and demulsification. The product requires no water washing, reducing wastewater treatment costs. This separation system and method achieve continuous separation of liquid diallyl and liquid inter-diethyl compounds.

[0052] Compared with existing technologies, the present invention has the following advantages: Based on continuous oil-water separation technology, the present invention adopts a continuous oil-water separation system and method, which can be combined with DCS logic interlock for self-control, shortening the material separation time, improving production efficiency, greatly increasing the solid content of the material and stabilizing the data, effectively recovering a small amount of floating oil and emulsified materials in the crude product, improving the material yield, reducing wastewater treatment costs, and realizing the continuous separation of liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide crude product.

[0053] The technical solution of this invention has the following advantages:

[0054] 1. By using a continuous oil-water separator, a floating oil intermediate tank, and a product oil intermediate tank, this invention can quickly separate the heavy oil, mother liquor water, and floating oil components of the product.

[0055] 2. By using an intermediate mother liquor tank and an ammonium chloride concentrate buffer tank, this invention performs salting-out and demulsification of emulsified oil in the mother liquor, effectively recovering emulsified materials and improving the overall yield of materials.

[0056] 3. Utilize density interlock control to achieve the enrichment and discharge of upper floating oil in the continuous oil-water separator, the re-separation of oil and water inside the floating oil intermediate tank and the product oil intermediate tank, and the enrichment and discharge of upper floating oil after salting out and demulsification in the mother liquor intermediate tank.

[0057] 4. Diallyl or m-diethyl crude products are processed through a continuous separation system, which achieves high efficiency in separating liquid materials. Some of the floating oil in the material can be directly and effectively recovered through the system without additional processing steps.

[0058] 5. Diallyl or m-diethyl crude products, after passing through a continuous separation system, significantly increase the solid content of the liquid product compared to static stratification and continuous overflow separation methods. The solid content data can be stably maintained at over 90wt%, and the system has good stability.

[0059] 6. The liquid product separated into the finished oil storage tank can be directly used in subsequent processes without the need for water washing, which can effectively reduce wastewater treatment costs. The separated mother liquor enters the MVR evaporation system, where it is evaporated, concentrated, and crystallized to obtain ammonium chloride salt and distilled water. At the same time, the ammonium chloride concentrate can be recycled back to the intermediate mother liquor tank for salt precipitation and demulsification, reducing production costs. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the structure of a continuous separation system for a liquid aniline derivative intermediate, as shown in the embodiment.

[0061] Figure 2 This is a schematic flowchart of a continuous separation method for a liquid aniline derivative intermediate, as shown in the embodiment. Detailed Implementation

[0062] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions or as recommended by the manufacturer.

[0063] This embodiment discloses a continuous separation method and system for liquid aniline derivative intermediates, relating to a continuous separation system for liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide, and a continuous separation method using this system. See [link to relevant documentation] for details. Figure 1 , Figure 2 .

[0064] like Figure 1 As shown, the continuous separation system for liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide in this embodiment includes a raw material buffer tank 1, a filter 2, a feed pump a, a continuous oil-water separator 3, a floating oil intermediate tank 4, a product oil intermediate tank 5, a mother liquor intermediate tank 6, a finished oil storage tank 7, an ammonium chloride concentrate buffer tank 8, a clear liquid pump b, an ammonium chloride concentrate transfer pump c, and an MVR evaporation system 9.

[0065] Raw material buffer tank 1, filter 2, feed pump a, and continuous oil-water separator 3 are connected in sequence. Mother liquor intermediate tank 6 is connected to continuous oil-water separator 3, floating oil intermediate tank 4, and product oil intermediate tank 5. The clear liquid outlet of mother liquor intermediate tank 6 is connected to MVR evaporation system 9 via clear liquid pump b. MVR evaporation system 9 is connected to ammonium chloride concentrate buffer tank 8. Ammonium chloride concentrate buffer tank 8 is connected to mother liquor intermediate tank 6 via ammonium chloride concentrate transfer pump c.

[0066] Raw material buffer tank 1 is used to store and mix liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid crude 3-(N,N-diethyl)aminoacetanilide.

[0067] Filter 2 is used to filter the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or crude liquid 3-(N,N-diethyl)aminoacetanilide, to prevent impurities present in the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or crude liquid 3-(N,N-diethyl)aminoacetanilide from entering the subsequent separation system and causing blockage of the subsequent separation system.

[0068] The continuous oil-water separator 3 is used to separate the upper floating oil, the lower product oil, and the intermediate mother liquor aqueous phase from the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide.

[0069] A first top valve connected to an intermediate floating oil tank 4 is installed near the top of the continuous oil-water separator 3. A first density meter ② is installed at the top of the continuous oil-water separator 3 to provide feedback on the density of the upper floating oil layer inside the separator. The first density meter ② and the first top valve form a density interlock, controlling the discharge of the upper floating oil layer inside the continuous oil-water separator 3 into the intermediate floating oil tank 4. During continuous feeding, the upper floating oil layer inside the continuous oil-water separator 3 continuously accumulates, forming a thicker floating oil layer. As the mother liquor aqueous phase level drops, when the density feedback from the first density meter ② changes from the mother liquor density to the floating oil density, the density interlock is triggered, and the system automatically opens the first top valve to discharge the upper floating oil layer into the intermediate floating oil tank 4. When the density feedback from the first density meter ② changes from the floating oil density to the mother liquor aqueous phase density, the system automatically closes the first top valve, stopping the discharge of floating oil. The floating oil above the continuous oil-water separator 3 continues the enrichment and discharge cycle.

[0070] A first central valve connected to the intermediate mother liquor tank 6 is provided in the middle of the continuous oil-water separator 3. A first lower valve connected to the intermediate product oil tank 5 is provided near the bottom of the continuous oil-water separator 3. A conductivity meter ① is installed inside the continuous oil-water separator 3 between the first central valve and the first lower valve (specifically at 1 / 3 of the overall height of the continuous oil-water separator 3 from the bottom in this embodiment). The conductivity meter ① is interlocked with the first central valve and the first lower valve. The opening of the first central valve and the first lower valve is adjusted according to the change in conductivity. The flow rate of heavy oil discharged from the bottom of the continuous oil-water separator 3 and the flow rate of water discharged from the intermediate layer mother liquor are adjusted in real time. This controls the discharge of the aqueous phase of the intermediate layer mother liquor and the lower layer product oil from the continuous oil-water separator 3 into the intermediate mother liquor tank 6 and the intermediate product oil tank 5, avoiding the situation of water being carried in the heavy oil discharged from the bottom of the continuous oil-water separator 3 and water being carried in the intermediate layer mother liquor.

[0071] The ratio of the volumetric flow rate of the lower layer product oil to the volumetric flow rate of the middle layer mother liquor water phase in the continuous oil-water separator can be controlled at 1:1.5 to 1:5, and can be further controlled at 1:1.85 to 1:4.

[0072] The conductivity of the lower layer product oil separated by the continuous oil-water separator 3 is preferably 500-5000 μS / cm, and more preferably 500-2000 μS / cm.

[0073] The intermediate oil tank 4 is used to receive the upper layer of floating oil separated by the continuous oil-water separator 3 and further separate the mother liquor aqueous phase from the upper layer of floating oil. In order to further improve the oil-water stratification effect in the intermediate oil tank 4, the temperature of the intermediate oil tank 4 can be controlled at 85-95℃, and further controlled at 88-93℃.

[0074] Near the top of the floating oil intermediate tank 4, a second upper valve is installed, which is connected to the finished oil storage tank 7. Near the bottom of the floating oil intermediate tank 4, a second lower valve is installed, which is connected to the mother liquor intermediate tank 6. A second density meter ③ is installed at the top of the floating oil intermediate tank 4 to provide feedback on the density of the upper layer of floating oil in the floating oil intermediate tank 4. The second density meter ③, together with the second upper valve and the second lower valve, or separately with the second lower valve, forms a density interlock to control the discharge of the upper layer of floating oil and the lower layer of mother liquor aqueous phase in the floating oil intermediate tank 4 into the finished oil storage tank 7 and the mother liquor intermediate tank 6. For example, the second densitometer ③ and the second lower valve form a density interlock to control the concentration of floating oil drainage. When the continuous oil-water separator 3 continuously discharges floating oil into the floating oil intermediate tank 4, the floating oil and mother liquor separate and accumulate inside the floating oil intermediate tank 4. When the density feedback of the second densitometer ③ is the mother liquor aqueous phase density, the density interlock is triggered, the second lower valve of the floating oil intermediate tank 4 opens, and the lower layer of mother liquor water is discharged. When the density feedback of the second densitometer ③ changes from the mother liquor aqueous phase density to the floating oil density, the system automatically closes the second lower valve, stops the drainage program of the floating oil intermediate tank 4, and the mother liquor water is discharged into the mother liquor intermediate tank 6. The second upper valve of the floating oil intermediate tank 4 is in the normally open state, and the concentrated floating oil inside is automatically discharged into the finished oil storage tank 7 when the liquid level is high.

[0075] The intermediate product oil tank 5 is used to receive the lower layer of product oil separated by the continuous oil-water separator 3 and further separate the mother liquor aqueous phase from the lower layer of product oil.

[0076] Near the top of the intermediate product oil tank 5, a third upper valve is installed, which is connected to the intermediate mother liquor tank 6. Near the bottom of the intermediate product oil tank 5, a third lower valve is installed, which is connected to the finished product oil storage tank 7. Inside the intermediate product oil tank 5, a third density meter ④ is installed to provide feedback on the density of the lower layer of product oil in the intermediate product oil tank 5. The third density meter ④, together with the third upper valve and the third lower valve, or alone with the third upper valve, forms a density interlock to control the discharge of the upper layer of mother liquor aqueous phase and the lower layer of product oil in the intermediate product oil tank 5 into the intermediate mother liquor tank 6 and the finished product oil storage tank 7. For example, the third density meter ④ and the third upper valve form a density interlock to control the heavy oil drainage and concentration. The initial feedback of the third density meter ④ in the intermediate product oil tank 5 is the heavy oil density. When the heavy oil at the bottom of the continuous oil-water separator 3 continuously enters the intermediate product oil tank 5, the heavy oil and a small amount of mother liquor separate inside the intermediate product oil tank 5. The upper layer is the mother liquor and the lower layer is the heavy oil. When the mother liquor continues to accumulate, the heavy oil level drops. When the density feedback of the third density meter ④ changes from the heavy oil density to the mother liquor density, the density interlock is triggered, and the third upper valve of the intermediate product oil tank 5 opens to discharge the upper layer of mother liquor water. When the density feedback of the third density meter ④ changes from the mother liquor density to the heavy oil density, the system automatically closes the third upper valve and stops the drainage program of the intermediate product oil tank 5. After the mother liquor water is discharged, it enters the intermediate mother liquor tank 6. When the system is running, the inflow and outflow of heavy oil inside the intermediate product oil tank 5 can be controlled to be the same. The outflowing heavy oil is discharged into the finished product oil storage tank 7.

[0077] The intermediate mother liquor tank 6 is used to receive the intermediate layer mother liquor aqueous phase separated by the continuous oil-water separator 3, the lower layer mother liquor aqueous phase separated by the floating oil intermediate tank 4, and the upper layer mother liquor aqueous phase separated by the product oil intermediate tank 5, and to carry out salting-out demulsification.

[0078] Near the top of the intermediate mother liquor tank 6, a fourth upper valve is installed, which is connected to the finished oil storage tank 7. Near the bottom of the intermediate mother liquor tank 6, a fourth lower valve is installed, which is connected to the continuous oil-water separator 3, the floating oil intermediate tank 4, and the finished oil intermediate tank 5. In the middle of the intermediate mother liquor tank 6, a second middle valve is installed, which is connected to the clear liquid pump b. At the bottom of the intermediate mother liquor tank 6, a fifth lower valve is installed, which is connected to the ammonium chloride concentrate transfer pump c. Near the top of the intermediate mother liquor tank 6, a fourth density meter ⑤ is installed, which is used to provide feedback on the density of the floating oil at the top of the intermediate mother liquor tank 6. The fourth density meter ⑤ and the fourth upper valve form a density interlock to control the discharge of the floating oil after demulsification in the upper layer of the intermediate mother liquor tank 5 into the finished oil storage tank 7. For example, when the mother liquor aqueous phase separated from the continuous oil-water separator 3, the floating oil intermediate tank 4, and the product oil intermediate tank 5 enters the mother liquor intermediate tank 6, the mother liquor aqueous phase mixes with the ammonium chloride concentrate transferred by the ammonium chloride concentrate transfer pump c, and salting out and demulsifying occurs. The demulsified oil phase exists in the form of floating oil and accumulates at the top of the mother liquor intermediate tank 6. When the density feedback of the fourth density meter ⑤ changes from the density of the mother liquor (i.e., the mother liquor after mixing with the ammonium chloride concentrate) to the density of the floating oil, the density interlock is triggered, the fourth valve at the top of the mother liquor intermediate tank 6 is opened, the floating oil is discharged into the finished oil storage tank 7, and the clear mother liquor is pumped into the MVR system by the clear liquid pump b. Furthermore, the intermediate mother liquor tank 6 is equipped with baffles to extend the residence time of the intermediate layer mother liquor aqueous phase separated by the continuous oil-water separator 3, the lower layer mother liquor aqueous phase separated by the floating oil intermediate tank 4, and the upper layer mother liquor aqueous phase separated by the product oil intermediate tank 5 inside the intermediate mother liquor tank 6. The ammonium chloride concentrate pipeline inlet at the bottom of the intermediate mother liquor tank 6 is equipped with a distributor to ensure that the ammonium chloride concentrate is evenly dispersed inside the intermediate mother liquor tank 6, achieving a good salting-out and demulsification effect.

[0079] The finished oil storage tank 7 is used to receive the floating oil after the mother liquor aqueous phase is separated from the floating oil intermediate tank 4, the product oil after the mother liquor aqueous phase is separated from the product oil intermediate tank 5, and the upper floating oil after salting out and demulsification from the mother liquor intermediate tank 6.

[0080] MVR evaporation system 9 is used to receive and process the mother liquor clear liquid from mother liquor intermediate tank 6. The mother liquor clear liquid enters MVR evaporation system 9 and is evaporated, concentrated and crystallized to obtain ammonium chloride salt and distilled water. Part of the ammonium chloride concentrate is recycled back to the mother liquor intermediate tank 6 for salt precipitation and demulsification.

[0081] The ammonium chloride concentrate buffer tank 8 is used to receive the ammonium chloride concentrate from the MVR evaporation system 9. The concentrate in the ammonium chloride concentrate buffer tank 8 is pumped into the mother liquor intermediate tank 6 by the ammonium chloride concentrate transfer pump c to demulsify the emulsion in the mother liquor water. A fifth density meter ⑥ is installed on the middle of the side of the ammonium chloride concentrate buffer tank 8 to monitor the density of the ammonium chloride concentrate discharged from the MVR evaporation system 9. When the ammonium chloride concentrate is introduced into the ammonium chloride concentrate buffer tank 8 from the MVR evaporation system 9, the temperature of the concentrate is reduced from high temperature (high temperature saturation state) to 88-93℃ and kept at that temperature. Some ammonium chloride crystals will precipitate. To maintain the homogeneity of the concentrate, the hot water valve on the top of the ammonium chloride concentrate buffer tank 8 (distilled hot water introduced from the MVR evaporation system 9, not shown in the figure) can be opened to stir and mix it.

[0082] The temperatures of the raw material buffer tank 1, continuous oil-water separator 3, intermediate product oil tank 5, and finished product oil storage tank 7 are controlled at 80–95℃, and can be further controlled at 80–88℃. If the tank insulation temperature is too low, the viscosity of the material increases, which is not conducive to the mixing of the material and also increases the risk of pipeline blockage. If the tank insulation temperature is too high, some heavy oil in the raw material buffer tank 1, continuous oil-water separator 3, and intermediate product oil tank 5 will float to the surface and form floating oil, affecting the oil-water separation effect. At the same time, if the finished product oil storage tank 7 is kept at an excessively high temperature for a long time, it will affect the quality of the liquid product.

[0083] At higher temperatures, the floating oil and mother liquor in the crude product exhibit good stratification. To further enhance the oil-water stratification effect in the intermediate oil tank, the temperature of the intermediate oil tank is preferably controlled at 85–95℃, and more preferably at 88–93℃. To ensure the salting-out and demulsification effect of the emulsified materials in the mother liquor and the stratification effect between the mother liquor and the floating oil (formed after the demulsification of the emulsified materials) after salting-out and demulsification, the temperatures of the intermediate mother liquor tank and the ammonium chloride concentrate buffer tank are preferably controlled at 85–95℃, and more preferably at 88–93℃.

[0084] In liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide crude product, the density of the upper floating oil (including the upper floating oil in the intermediate tank of the mother liquor) is 1005-1020 kg / m³. 3 The density of the mother liquor is between 1025 and 1038 kg / m³. 3 The density of the lower layer heavy oil (product oil) is 1040-1050 kg / m³. 3 When the density meters at the top of the continuous oil-water separator, floating oil intermediate tank, product oil intermediate tank, and mother liquor intermediate tank change from the density of the mother liquor aqueous phase to the density of the floating oil or heavy oil, or vice versa, the density interlock opens or closes the corresponding valve. To avoid water carrying over material or material carrying over to the outlet and to control the solid content of the product, the density of the upper floating oil (including the upper floating oil in the mother liquor intermediate tank) is further preferably 10¹⁰~10¹⁸ kg / m³.3 The water density of the mother liquor is further preferably 1025–1035 kg / m³. 3 The density of the lower layer heavy oil (product oil) is further preferably 1042–1048 kg / m³. 3 The optimized density is used as density interlocking data. The density of the concentrate in the ammonium chloride concentrate buffer tank is controlled at 1080-1100 kg / m³. 3 The ammonium chloride concentrate in the buffer tank is circulated and introduced into the tank by the MVR evaporation system. The introduced ammonium chloride concentrate is in a high-temperature saturated state. When the temperature is controlled at 88-93°C after entering the ammonium chloride concentrate buffer tank, some ammonium chloride crystals will precipitate. To maintain the homogeneity of the concentrate solution and the salting-out and demulsification effect, the circulating distillation hot water valve (introduced by the MVR system, not shown in the figure) is opened to further optimize the density to 1090-1100 kg / m³. 3 The water density of the mother liquor from the intermediate tank for salting out and demulsifying is controlled at 1055–1070 kg / m³ by adjusting the feed rate of the ammonium chloride concentrate. 3 The optimized density is used as density interlocking data.

[0085] In the above-mentioned continuous separation system, the insulation medium for pipes, vessels, etc. can be one or both of low-pressure steam and hot water.

[0086] See Figure 2 A continuous separation method for liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide, employing... Figure 1 And the continuous separation system of liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide described above.

[0087] The continuous separation method for liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide includes:

[0088] Diallyl or meta-diethyl crude product is pumped into raw material buffer tank 1 and stirred until homogeneous. The crude product is then pumped into continuous oil-water separator 3 via feed pump a.

[0089] The continuous oil-water separator 3 is used to separate the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide into an upper floating oil layer, a lower product oil layer, and an intermediate mother liquor aqueous phase.

[0090] The floating oil intermediate tank 4 is used to receive the upper layer of floating oil separated by the continuous oil-water separator 3 and further separate the mother liquor aqueous phase from the upper layer of floating oil.

[0091] The intermediate product oil tank 5 receives the lower layer of product oil separated by the continuous oil-water separator 3 and further separates the mother liquor aqueous phase from the lower layer of product oil.

[0092] The intermediate mother liquor tank 6 receives the intermediate layer mother liquor aqueous phase separated by the continuous oil-water separator 3, the lower layer mother liquor aqueous phase separated by the floating oil intermediate tank 4, and the upper layer mother liquor aqueous phase separated by the product oil intermediate tank 5, and performs salting out and demulsification.

[0093] The finished oil storage tank 7 receives the floating oil after the mother liquor aqueous phase is separated from the intermediate tank 4, the product oil after the mother liquor aqueous phase is separated from the intermediate tank 5, and the upper floating oil after salting out and demulsifying the mother liquor in the intermediate tank 6.

[0094] The MVR evaporation system 9 receives and processes the mother liquor clear liquid from the intermediate mother liquor tank 6. The mother liquor clear liquid enters the MVR evaporation system 9 and is evaporated, concentrated, and crystallized to obtain ammonium chloride salt and distilled water. Part of the ammonium chloride concentrate enters the ammonium chloride concentrate buffer tank 8 and is recycled back to the intermediate mother liquor tank 6 for salting out and demulsification.

[0095] The crude oil content of the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide can be 15wt% to 40wt%, and more preferably 20wt% to 35wt%.

[0096] The purity of the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide is preferably not less than 95%, and the salt content of the crude mother liquor is 10wt% to 25wt%, more preferably 15wt% to 20wt%.

[0097] The solid content of the material in the finished oil storage tank 7 is greater than 88 wt%. In order to reduce the increase in salt content caused by the mother liquor water in the product, the solid content of the material in the finished oil storage tank 7 is further optimized and controlled to be greater than 90 wt%.

[0098] Application Example 1

[0099] Taking liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide as an example, the crude product was subjected to oil-water separation using the continuous separation system and method described in the above examples.

[0100] The temperature of the raw material buffer tank 1, continuous oil-water separator 3, product oil intermediate tank 5, and finished oil storage tank 7 is controlled at 80-85℃, while the temperature of the floating oil intermediate tank 4, mother liquor intermediate tank 6, and ammonium chloride concentrate buffer tank 8 is controlled at 91-93℃. Diallyl crude product with a purity of 95%-95.6%, a mother liquor salt content of 15wt%-16.5wt%, and an oil content of 20wt%-25wt% is pumped into the raw material buffer tank 1. Stirring is started, and feed pump a pumps the crude product into the continuous oil-water separator 3. The flow rate of heavy oil discharge from the bottom of the continuous oil-water separator 3 and the intermediate mother liquor discharge are set, with a volume flow rate ratio controlled at 1:3-1:4. Flow interlock is activated. At the same time, the density interlock of the continuous oil-water separator 3, floating oil intermediate tank 4, product oil intermediate tank 5, and mother liquor intermediate tank 6 is activated. The density interlock data are as follows: the density of floating oil (including the floating oil on the upper layer of the mother liquor intermediate tank) is 10¹²-10¹⁵ kg / m³. 3 The water density of the crude mother liquor is 1025–1030 kg / m³. 3 The density of the lower layer heavy oil (product oil) is 1045–1047 kg / m³. 3 The water density of the mother liquor from the intermediate salting-out tank is 1058-1062 kg / m³. 3 The conductivity of the lower 1 / 3 of the side of the continuous oil-water separator 3 is controlled at 500-1000 μS / cm. Material is continuously pumped in by the feed pump a, and the upper layer of floating oil in the continuous oil-water separator 3 is continuously concentrated. When the density interlock is triggered, the first upper valve automatically opens, and the floating oil and a small amount of mother liquor water enter the intermediate oil tank 4. Inside the intermediate oil tank 4, the floating oil and mother liquor water separate. When the density interlock is triggered, the second lower valve automatically opens to drain the water, and the floating oil, after continuous concentration and enrichment, enters the finished oil storage tank 7. The lower layer of heavy oil from the continuous oil-water separator 3 enters the intermediate product oil tank 5, where oil-water separation continues. When the density interlock is triggered, the system opens the third upper valve of the intermediate product oil tank 5 to drain the water, and the heavy oil is discharged to the finished oil storage tank 7. The density of the ammonium chloride concentrate in the ammonium chloride concentrate buffer tank 8 is adjusted to 1090-1095 kg / m³ using distilled hot water. 3 The intermediate layer of mother liquor water from the continuous oil-water separator 3, the lower layer of mother liquor water from the floating oil intermediate tank 4, and the upper layer of mother liquor water from the product oil intermediate tank 5, along with ammonium chloride concentrate, enter the mother liquor intermediate tank 6 for salting-out demulsification. When the floating oil at the top of the mother liquor intermediate tank 6 (the floating oil formed after demulsification) accumulates and triggers the density interlock, the fourth valve above the mother liquor intermediate tank 6 opens, and the floating oil is discharged into the finished oil storage tank 7. The clarified mother liquor after salting-out demulsification enters the MVR evaporation system for evaporation, concentration, and crystallization to obtain ammonium chloride salt and distilled water. The ammonium chloride concentrate is recycled back for salting-out demulsification in the mother liquor intermediate tank 6, while the ammonium chloride salt and distilled hot water can be used for density control in the ammonium chloride concentrate buffer tank 8.

[0101] The system continuously feeds and extracts materials 24 hours a day. After testing, the purity of the separated liquid diallyl is 95% to 95.6%, and the purity remains unchanged before and after separation. The solid content is 92 wt% to 93 wt%.

[0102] Application Example 2

[0103] Taking liquid 3-(N,N-diethyl)aminoacetanilide as an example, the crude product is subjected to oil-water separation using the continuous separation system and method described in the above embodiments.

[0104] The temperature of the hot water-controlled raw material buffer tank 1, continuous oil-water separator 3, product oil intermediate tank 5, and finished oil storage tank 7 is 85-88℃, while the temperature of the floating oil intermediate tank 4, mother liquor intermediate tank 6, and ammonium chloride concentrate buffer tank 8 is 89-92℃. Crude m-diethyl chloride with a purity of 95.5%-96.3%, a mother liquor salt content of 16.8wt%-18.5wt%, and an oil content of 22wt%-27wt% is pumped into the raw material buffer tank 1, and the agitator is started. Feed pump a pumps the crude product into continuous oil-water separator 3. The flow rates of heavy oil discharged from the bottom of continuous oil-water separator 3 and intermediate mother liquor discharged are set, with a volumetric flow rate ratio controlled at 1:2.7 to 1:3.5. Flow interlocking is activated. Simultaneously, density interlocking is activated for continuous oil-water separator 3, intermediate floating oil tank 4, intermediate product oil tank 5, and intermediate mother liquor tank 6. The density interlocking data are as follows: the density of floating oil (including the upper layer of floating oil in the intermediate mother liquor tank) is 10¹⁴ to 10¹⁶ kg / m³. 3 The water density of the crude mother liquor is 1028–1032 kg / m³. 3 The density of the lower layer heavy oil (product oil) is 1046–1048 kg / m³. 3 The water density of the mother liquor from the intermediate salting-out tank is 1064-1068 kg / m³. 3 The conductivity of the lower 1 / 3 of the side of the continuous oil-water separator 3 is controlled at 1000-2000 μS / cm. Material is continuously pumped in by the feed pump a, and the upper layer of floating oil in the continuous oil-water separator 3 is continuously concentrated. When the density interlock is triggered, the first upper valve automatically opens, and the floating oil and a small amount of mother liquor water enter the floating oil intermediate tank 4. Inside the floating oil intermediate tank 4, the floating oil and mother liquor water separate. When the density interlock is triggered, the second lower valve automatically opens to drain the water, and the floating oil, after continuous concentration and enrichment, enters the finished oil storage tank 7. The lower layer of heavy oil from the continuous oil-water separator 3 enters the product oil intermediate tank 5, where oil-water separation continues. When the density interlock is triggered, the system opens the third upper valve of the product oil intermediate tank 5 to drain the water, and the heavy oil is discharged to the finished oil storage tank 7. The density of the ammonium chloride concentrate in the ammonium chloride concentrate buffer tank 8 is adjusted to 1094-1098 kg / m³ using distilled hot water. 3The intermediate mother liquor water from the continuous oil-water separator 3, the lower layer of mother liquor water from the floating oil intermediate tank 4, and the upper layer of mother liquor water from the product oil intermediate tank 5, along with ammonium chloride concentrate, enter the mother liquor intermediate tank 6 for salting-out demulsification. When the floating oil at the top of the mother liquor intermediate tank 6 (the floating oil formed after demulsification) accumulates and triggers the density interlock, the fourth valve above the mother liquor intermediate tank 6 opens, and the floating oil is discharged into the finished oil storage tank 7. The clarified mother liquor after salting-out demulsification enters the MVR evaporation system for evaporation, concentration, and crystallization to obtain ammonium chloride salt and distilled water. The ammonium chloride concentrate is recycled back for salting-out demulsification in the mother liquor intermediate tank 6, while the ammonium chloride salt and distilled hot water can be used for density control in the ammonium chloride concentrate buffer tank 8.

[0105] The system continuously feeds and extracts materials 24 hours a day. After testing, the purity of the separated liquid diethyl is 95.5% to 96.3%, and the purity remains unchanged before and after separation. The solid content is 91.2 wt% to 92.5 wt%.

[0106] Comparative Example 1

[0107] In a 12000L enamel-lined reactor, crude diallyl material with a purity of 95.6% and a salt content of 16.2 wt% in the mother liquor was introduced. The temperature was controlled at 82–84℃, and the mixture was allowed to stand for 4 hours to separate into layers. The heavy oil at the bottom was pumped into a storage tank for insulation and later use, or directly used in subsequent production. The separated liquid had a diallyl purity of 95.4% and a solids content of 57.8 wt%. Some floating oil on the upper layer of the separated mother liquor and emulsified materials could not be separated and required additional processing for recovery.

[0108] Comparative Example 2

[0109] In a 12000L enamel-lined reactor, crude m-diethyl material with a purity of 95% and a salt content of 18wt% in the mother liquor was introduced. The temperature was controlled at 83-87℃, and the mixture was allowed to stand for 6 hours to separate into layers. The heavy oil at the bottom was pumped into a storage tank for insulation and later use or directly used in subsequent production. The separated liquid m-diethyl material had a purity of 95% and a solid content of 68.2wt%. Some floating oil and emulsified materials in the upper layer of the separated mother liquor could not be separated and required additional processing for recovery.

[0110] As can be seen from the above application examples and comparative examples, the continuous separation system and method of the present invention can significantly increase the solid content of liquid diallyl or m-diethyl, effectively recover floating oil components in crude product and emulsified materials in mother liquor, improve material yield, shorten separation time, thoroughly separate oil and water, increase product solid content and stabilize data, and reduce wastewater treatment costs.

[0111] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A continuous separation system for a liquid aniline derivative intermediate, wherein the liquid aniline derivative intermediate is liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide, characterized in that, The crude oil content of the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide is 15wt% to 40wt%, and the water content of the mother liquor of the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide is 10wt% to 25wt%. The continuous separation system for the liquid aniline derivative intermediate includes: A continuous oil-water separator (3) is used to separate the upper floating oil, the lower product oil and the middle mother liquor aqueous phase from the liquid crude 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide. The intermediate oil tank (4) is used to receive the upper layer of floating oil separated by the continuous oil-water separator (3) and further separate the mother liquor aqueous phase from the upper layer of floating oil. The intermediate product oil tank (5) is used to receive the lower layer product oil separated by the continuous oil-water separator (3) and further separate the mother liquor aqueous phase from the lower layer product oil. The intermediate mother liquor tank (6) is used to receive the intermediate layer mother liquor aqueous phase separated by the continuous oil-water separator (3), the lower layer mother liquor aqueous phase separated by the floating oil intermediate tank (4), and the upper layer mother liquor aqueous phase separated by the product oil intermediate tank (5), and to form the upper layer floating oil and the lower layer mother liquor clear liquid by salting out and demulsifying. The finished oil storage tank (7) is used to receive the floating oil after the mother liquor aqueous phase is separated from the floating oil intermediate tank (4) and the product oil after the mother liquor aqueous phase is separated from the product oil intermediate tank (5) and the upper floating oil formed after salting out and demulsification of the mother liquor intermediate tank (6); the solid content of the material in the finished oil storage tank (7) is greater than 85wt%. MVR evaporation system (9) is used to receive and process the lower layer of mother liquor clear liquid from the mother liquor intermediate tank (6). The lower layer of mother liquor clear liquid enters the MVR evaporation system (9) and is evaporated, concentrated and crystallized to obtain ammonium chloride salt and distilled water. At the same time, part of the ammonium chloride concentrate is returned to the mother liquor intermediate tank (6) for salting out and demulsification. The continuous oil-water separator (3) is equipped with a first upper valve connected to the floating oil intermediate tank (4) near the top. The top of the continuous oil-water separator (3) is equipped with a first density meter for feedback of the density of the upper floating oil in the continuous oil-water separator (3). The first density meter and the first upper valve form a density interlock to control the upper floating oil in the continuous oil-water separator (3) to be discharged into the floating oil intermediate tank (4). A first middle valve connected to the mother liquor intermediate tank (6) is provided in the middle of the continuous oil-water separator (3), and a first lower valve connected to the product oil intermediate tank (5) is provided near the bottom of the continuous oil-water separator (3). A conductivity meter is provided in the continuous oil-water separator (3) between the first middle valve and the first lower valve. The conductivity meter is interlocked with the first middle valve and the first lower valve. The opening of the first middle valve and the first lower valve is adjusted according to the change in conductivity to control the discharge of the mother liquor aqueous phase in the middle layer and the product oil in the lower layer of the continuous oil-water separator (3) into the mother liquor intermediate tank (6) and the product oil intermediate tank (5).

2. The continuous separation system for liquid aniline derivative intermediates according to claim 1, characterized in that, The continuous separation system for the liquid aniline derivative intermediate also includes an ammonium chloride concentrate buffer tank (8); The ammonium chloride concentrate buffer tank (8) is used to receive and store the ammonium chloride concentrate produced by the MVR evaporation system (9) and to supply the ammonium chloride concentrate to the mother liquor intermediate tank (6) for salting out and demulsification.

3. The continuous separation system for liquid aniline derivative intermediates according to claim 1, characterized in that, The continuous separation system for the liquid aniline derivative intermediate also includes a raw material buffer tank (1) and a filter (2); the raw material buffer tank (1), the filter (2), and the continuous oil-water separator (3) are connected in sequence; The raw material buffer tank (1) is used to store and mix liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid crude 3-(N,N-diethyl)aminoacetanilide; The temperature of the raw material buffer tank (1) is controlled at 80-95℃.

4. The continuous separation system for liquid aniline derivative intermediates according to claim 1, characterized in that, The floating oil intermediate tank (4) is equipped with a second upper valve near the top that connects to the finished oil storage tank (7), and the floating oil intermediate tank (4) is equipped with a second lower valve near the bottom that connects to the mother liquor intermediate tank (6). The top of the floating oil intermediate tank (4) is equipped with a second density meter for feeding back the density of the upper layer of floating oil in the floating oil intermediate tank (4). The second density meter, together with the second upper valve and the second lower valve, or alone with the second lower valve, forms a density interlock to control the discharge of the upper layer of floating oil and the lower layer of mother liquor aqueous phase in the floating oil intermediate tank (4) into the finished oil storage tank (7) and the mother liquor intermediate tank (6).

5. The continuous separation system for liquid aniline derivative intermediates according to claim 1, characterized in that, The intermediate product oil tank (5) is equipped with a third upper valve near the top, which is connected to the intermediate mother liquor tank (6). The intermediate product oil tank (5) is equipped with a third lower valve near the bottom, which is connected to the finished product oil storage tank (7). The intermediate product oil tank (5) is equipped with a third density meter at the top, which is used to provide feedback on the density of the lower layer of product oil in the intermediate product oil tank (5). The third density meter, together with the third upper valve and the third lower valve, or together with the third upper valve alone, forms a density interlock to control the discharge of the upper layer of mother liquor aqueous phase and the lower layer of product oil in the intermediate product oil tank (5) into the intermediate mother liquor tank (6) and the finished product oil storage tank (7).

6. The continuous separation system for liquid aniline derivative intermediates according to claim 1, characterized in that, The intermediate mother liquor tank (6) is equipped with a fourth upper valve near the top that is connected to the finished oil storage tank (7). The intermediate mother liquor tank (6) is equipped with a second middle valve that is connected to the MVR evaporation system (9). The top of the intermediate mother liquor tank (6) is equipped with a fourth density meter for feeding back the density of the upper floating oil in the intermediate mother liquor tank (6). The fourth density meter and the fourth upper valve form a density interlock to control the discharge of the upper floating oil after salt precipitation and demulsification in the intermediate mother liquor tank (6) into the finished oil storage tank (7).

7. A continuous separation method for a liquid aniline derivative intermediate, wherein the liquid aniline derivative intermediate is liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide, characterized in that, The continuous separation system for liquid aniline derivative intermediates as described in any one of claims 1 to 6 is employed. The continuous separation method for the liquid aniline derivative intermediate includes: A continuous oil-water separator (3) is used to separate the upper floating oil, the lower product oil, and the intermediate mother liquor aqueous phase from the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide. The floating oil intermediate tank (4) is used to receive the upper layer of floating oil separated by the continuous oil-water separator (3) and further separate the mother liquor aqueous phase from the upper layer of floating oil; The intermediate product oil tank (5) receives the lower layer of product oil separated by the continuous oil-water separator (3) and further separates the mother liquor aqueous phase from the lower layer of product oil. The intermediate mother liquor tank (6) receives the intermediate layer mother liquor aqueous phase separated by the continuous oil-water separator (3), the lower layer mother liquor aqueous phase separated by the floating oil intermediate tank (4), and the upper layer mother liquor aqueous phase separated by the product oil intermediate tank (5), and performs salting out and demulsification to form upper floating oil and lower clear mother liquor. The finished oil storage tank (7) receives the floating oil after the mother liquor aqueous phase is separated in the intermediate tank (4) and the product oil intermediate tank (5) after the mother liquor aqueous phase is separated and the upper floating oil formed after salting out and demulsification in the intermediate tank (6). The MVR evaporation system (9) is used to receive and process the lower layer of mother liquor clear liquid from the intermediate mother liquor tank (6). The lower layer of mother liquor clear liquid enters the MVR evaporation system (9) and is evaporated, concentrated, and crystallized to obtain ammonium chloride salt and distilled water. At the same time, part of the ammonium chloride concentrate is returned to the intermediate mother liquor tank (6) for salting out and demulsification.

8. The continuous separation method for liquid aniline derivative intermediates according to claim 7, characterized in that, The crude oil content of the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide is 15wt% to 40wt%, wherein the purity of the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide is not less than 95%, and the water salt content of the crude mother liquor of the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide is 10wt% to 25wt%. The solid content of the material in the finished oil storage tank (7) is greater than 85 wt%.

9. The continuous separation method for liquid aniline derivative intermediates according to claim 7, characterized in that, The ratio of the volumetric flow rate of the lower layer product oil to the volumetric flow rate of the middle layer mother liquor water phase in the continuous oil-water separator (3) is controlled at 1:1.5 to 1:

5. The conductivity of the lower layer product oil separated by the continuous oil-water separator (3) is 500-5000 μS / cm; The temperature of the continuous oil-water separator (3), the intermediate product oil tank (5), and the finished product oil storage tank (7) is controlled at 80-95℃; The continuous separation method for the liquid aniline derivative intermediate also includes using an ammonium chloride concentrate buffer tank (8) to receive and store the ammonium chloride concentrate generated by the MVR evaporation system (9) and supply the ammonium chloride concentrate to the mother liquor intermediate tank (6) for salting out and demulsification. The temperatures of the intermediate oil tank (4), the intermediate mother liquor tank (6), and the ammonium chloride concentrate buffer tank (8) are controlled at 85-95℃; The density of the upper layer of floating oil in the crude liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide and the upper layer of floating oil in the intermediate tank (6) of the mother liquor is 1005-1020 kg / m³. 3 The water density of the mother liquor in the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide crude product is 1025-1038 kg / m³. 3 The product oil density in the liquid 3-(N,N-diallyl)amino-4-methoxyacetanilide or liquid 3-(N,N-diethyl)aminoacetanilide crude product is 1040-1050 kg / m³. 3 ; The density of ammonium chloride concentrate in the ammonium chloride concentrate buffer tank (8) is 1080-1100 kg / m³ 3 ; The density of the clear lower layer of mother liquor formed by salting out and demulsifying in the intermediate mother liquor tank (6) is controlled at 1055-1070 kg / m³ by adjusting the feed rate of the ammonium chloride concentrate. 3 .

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