Fatty amine discharge separation and recovery system

Abstract

This utility model relates to the field of fatty amine production technology, specifically a fatty amine discharge separation and recovery system. The fatty amine discharge separation and recovery system includes a reaction vessel, which is connected to a horizontal separator via a pre-filter. The horizontal separator is connected to a centrifugal separator via a conical bottom stirred settling tank. The centrifugal separator is connected to a coarse distillation column and a fine distillation column. The top of the fine distillation column is connected to a condenser via a vacuum pump. This system, employing a three-stage catalyst separation system of "conical bottom stirred settling tank + centrifugal separator + fine filter," achieves efficient recovery of nanoscale and colloidal catalysts, reduces precious metal loss, and simultaneously avoids catalyst contamination of the distillation system, ensuring product purity.

Description

Technical Field

[0001] This utility model relates to the field of fatty amine production technology, specifically to a fatty amine discharge separation and recovery system. Background Technology

[0002] Aliphatic amines (especially secondary amines) are key organic chemical products in the fields of surfactants, pharmaceutical intermediates, and pesticide raw materials. Their production requires a process of "raw material reaction → product separation → purification and recovery". The composition of the reaction vessel discharge system is complex, containing secondary amines, unreacted primary amines / lower alcohols, hydrogen / alkane gaseous by-products, Ni / Cu-Zn-Al noble metal catalyst particles, as well as mechanical impurities such as tertiary amines / polyamines with high boiling points and scale on the inner wall of the reaction vessel.

[0003] In the existing workshop production, the separation and recovery system has many problems: large-particle impurities directly enter downstream units, causing blockage of the gas-liquid separator wire mesh demister and contamination of distillation trays / packing, requiring frequent shutdowns for cleaning and affecting production continuity; catalyst separation is incomplete, with nano-sized or colloidal catalysts easily penetrating the filter media, resulting in waste of precious metals and contamination of the distillation system, reducing product purity; energy utilization is unreasonable, with each unit operating independently, and the heating of the settling tank and the cooling of the condenser not forming an energy cycle, resulting in high energy consumption; the purity of the recovered raw materials is insufficient, with low-boiling-point substances from the top of the coarse distillation column being directly reused, while entrained high-boiling-point substances accumulate in the reaction system, reducing the selectivity of secondary amines and product yield. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a fatty amine discharge separation and recovery system. By adopting a three-stage catalyst separation system of "conical bottom stirred settling tank + centrifugal separator + fine filter", it achieves efficient recovery of nano-scale and colloidal catalysts, reduces precious metal loss, avoids catalyst contamination of the distillation system, and ensures product purity.

[0005] This utility model is achieved using the following technical solution: The aforementioned fatty amine discharge separation and recovery system includes a reaction vessel, which is connected to a horizontal separator via a pre-filter. The horizontal separator is connected to a centrifugal separator via a conical bottom stirred settling tank. The centrifugal separator is connected to a coarse distillation column and a precision distillation column. The top of the precision distillation column is connected to a condenser via a vacuum pump.

[0006] The pre-filter is internally configured with a series of components: an inclined baffle (30°-45°), a recessed collection box (with an arc-shaped bottom), and a 10μm pore size filter screen. The inclined baffle is located below the feed inlet, and the recessed collection box is below the inclined baffle. The inclined baffle guides the material, preventing impurities deposited in the recessed collection box from re-rising and reducing filter screen clogging. This three-stage structure works synergistically, resulting in a high impurity removal rate, protecting the subsequent horizontal separator's wire mesh demister, and extending the cleaning cycle.

[0007] The horizontal separator comprises a horizontal cylindrical shell with a corrugated 200-mesh stainless steel wire mesh demister in the middle section. The feed inlet is located slightly below the middle, the gas phase outlet is at the top, and the liquid phase outlet is at the bottom. The horizontal structure extends the material residence time, facilitating thorough gas-liquid separation; the corrugated wire mesh demister increases the contact area, efficiently removing amine mist, ensuring hydrogen purity, and reducing environmental and safety risks.

[0008] The conical bottom of the agitated settling tank facilitates catalyst deposition; the propeller-type agitator promotes catalyst agglomeration and improves settling efficiency; the coil and condenser circulate energy, saving energy and shortening settling time.

[0009] A fine filter is provided between the centrifuge and the crude distillation column, and the condenser is connected to the reactor through an adsorption column. A backwash filter is provided between the condenser and the adsorption column.

[0010] The pre-filter is equipped with a filter screen inside, and a recessed collection box is located on the side of the filter screen and near the reactor. An inclined baffle is located above the recessed collection box. A wire mesh demister is located inside the horizontal separator.

[0011] The recessed collection box and the inclined baffle are both located inside the pre-filter.

[0012] The conical bottom stirred settling tank is equipped with an agitator inside, and a settling tank coil is provided on the outside of the agitator. The condenser is equipped with a condenser coil inside, and a coolant inlet pipe is connected to the condenser coil. The condenser coil is connected to the settling tank coil through a connecting pipe.

[0013] The fine filter has a filter plate inside, and a rotating scraper is located below the filter plate. The upper edge of the rotating scraper is tangent to the lower edge of the filter plate.

[0014] The centrifugal separator is connected to the fine filter via a pipe located below the filter plate, while the coarse distillation column is connected to the fine filter via a pipe located above the filter plate. The top of the coarse distillation column is connected to the condenser via a vacuum pump.

[0015] The crude distillation column is a valve tray structure with 30-40 trays. It features a low-boiling-point outlet and vacuum pump interface at the top, a side-stream secondary amine crude product outlet in the middle, and a high-boiling-point outlet and reboiler interface at the bottom. The valve tray structure offers stable separation efficiency and high throughput, effectively separating low-boiling-point substances, secondary amine crude products, and high-boiling-point substances, laying the foundation for subsequent precision distillation and improving overall separation efficiency.

[0016] The precision distillation column is a corrugated packed column (packing specific surface area 500 m²). 2 / m 3The top is equipped with a trace low-boiling-point outlet, the middle with a side-stream secondary amine finished product outlet, and the bottom with a trace high-boiling-point outlet and reboiler interface. It is equipped with a high-precision temperature and pressure control system. The corrugated packing has high mass transfer efficiency, is suitable for heat-sensitive materials, and can deeply remove trace impurities from secondary amines, ensuring the purity of the finished product is ≥99.0%, meeting the high purity requirements of downstream applications.

[0017] The working principle of this utility model is as follows: Pretreatment stage: Open the discharge valve of the reactor and introduce the aliphatic amine mixture into the pre-filter. Control the material flow rate to 0.5-0.8 m / s and maintain the temperature inside the filter. Use inclined baffles (30°-45°), a recessed collection box, and a 10μm pore size filter screen to intercept large-particle mechanical impurities. After pretreatment, the material is introduced into a horizontal separator, maintaining the pressure inside the separator at 0.4-0.6 MPa. The material is held for 5-10 minutes and then separated into gas phase (hydrogen + trace alkanes + amine mist removed) and liquid phase (secondary amine + primary amine + lower alcohols + catalyst) through a 200-mesh wire demister. The liquid phase from the horizontal separator is introduced into a conical bottom stirred settling tank. After turning on the stirrer at 150-200 r / min and raising the temperature, the colloidal catalyst agglomerates and settles at the bottom of the conical tank. The supernatant is discharged. The supernatant is introduced into a centrifugal separator, where the catalyst is separated at a speed of 3000-5000 r / min. After centrifugation, the liquid phase is introduced into a fine filter, and a rotating scraper is turned on at 50-80 r / min. The residual catalyst is intercepted through the 0.5 μm pore size filter plate to ensure that the catalyst content in the filtered liquid phase is ≤5 ppm.

[0018] Distillation and purification stage: After fine filtration, the liquid phase is introduced into a crude distillation column. In the valved column (30-40 trays), low-boiling components are collected at 80-90℃. At the bottom of the column, at 0.1-0.12 MPa and 180-200℃ (high-boiling components are discharged), and at a side stream of 120-140℃, the crude secondary amine is collected. Under a reflux ratio of 3-5:1, light and heavy components are separated. The crude secondary amine is then introduced into a precision distillation column. In the corrugated packed column, trace amounts of low-boiling components are discharged at the top. At the bottom of the column, at 0.08-0.1 MPa and 160-180℃, trace amounts of high-boiling components are discharged. At a side stream of 110-120℃, the finished secondary amine product is collected with a purity ≥99.0%, purified under a reflux ratio of 8-12:1.

[0019] Raw material recovery and reuse stage: Low-boiling-point substances from the condenser are introduced into a backwash filter and filtered through a 0.22μm filter element at 40-50℃ and 0.3-0.5MPa. Backwashing with compressed air every 30 minutes removes solid impurities. The filtered raw material is then introduced into an adsorption tower at 30-40℃ and a space velocity of 1-2 h⁻¹. -1Under certain conditions, the raw material is adsorbed by activated alumina (to remove high-boiling-point substances) and 3A molecular sieve (to remove moisture) for 4-6 hours to ensure a purity of ≥99%. After purification, the raw material is introduced into the reactor at a pressure of 0.6-0.8 MPa and a recycling ratio of 50%-70%, and mixed with fresh raw material (at 80-90℃) to participate in the reaction.

[0020] Compared with the prior art, the beneficial effects of this utility model are: (1) By adding a pre-filter consisting of "inclined baffle + recessed collection box + filter screen" between the reactor and the horizontal separator, large-particle mechanical impurities are intercepted in advance, avoiding blockage of subsequent equipment, extending the equipment cleaning cycle, and improving production continuity. By adopting a three-stage catalyst separation system consisting of "conical bottom stirred settling tank + centrifugal separator + fine filter", efficient catalyst recovery is achieved, reducing precious metal loss, while avoiding catalyst contamination of the distillation system and ensuring product purity.

[0021] (2) By installing a corrugated wire mesh demister inside the horizontal separator, amine mist in hydrogen is completely removed, which not only meets environmental emission requirements but also avoids the poisoning of the reaction catalyst by recycled hydrogen, while eliminating the risk of explosion in the distillation unit. By connecting the condenser coil and the settling tank coil in series through connecting pipes, energy recycling is achieved. The high-temperature coolant from the condenser is used to heat the settling tank, reducing steam consumption and overall energy consumption. By adding a backwash filter and adsorption tower between the condenser and the reactor, deep purification and recovery of raw materials are achieved, removing trace impurities and moisture, ensuring the purity of the reused raw materials, improving the selectivity of secondary amines and product yield, and reducing the consumption of fresh raw materials. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the fatty amine discharge separation and recovery system of this utility model; In the diagram: 1. Reactor; 2. Pre-filter; 3. Horizontal separator; 4. Conical bottom stirred settling tank; 5. Centrifugal separator; 6. Fine filter; 7. Coarse distillation column; 8. Precision distillation column; 9. Condenser; 10. Backwash filter; 11. Filter screen; 12. Recessed collection box; 13. Inclined baffle; 14. Wire mesh demister; 15. Agitator; 16. Settling tank coil; 17. Filter plate; 18. Rotary scraper; 19. Condenser coil; 20. Connecting pipe; 21. Coolant inlet pipe; 22. Adsorption tower. Detailed Implementation

[0023] To make the objectives and technical solutions of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0024] Example 1 like Figure 1As shown, the fatty amine discharge separation and recovery system includes a reactor 1. The reactor 1 is connected to a horizontal separator 3 via a pre-filter 2. The horizontal separator 3 is connected to a centrifugal separator 5 via a conical bottom stirred settling tank 4. The centrifugal separator 5 is connected to a coarse distillation column 7 and a fine distillation column 8. The top of the fine distillation column 8 is connected to a condenser 9 via a vacuum pump. A fine filter 6 is installed between the centrifugal separator 5 and the coarse distillation column 7. The condenser 9 is connected to the reactor 1 via an adsorption column 22. A backwash filter 10 is installed between the condenser 9 and the adsorption column 22. The pre-filter 2 contains a filter screen 11. A recessed collection box 12 is located near the reactor 1, and an inclined baffle 13 is installed above the recessed collection box 12. A wire mesh demister 14 is installed inside the horizontal separator 3. Both the recessed collection box 12 and the inclined baffle 13 are located inside the pre-filter 2. The conical-bottom stirred settling tank 4 is equipped with an agitator 15 inside, and a settling tank coil 16 is located outside the agitator 15. The condenser tank 9 is equipped with a condenser coil 19 inside, and a coolant inlet pipe 21 is connected to the condenser coil 19. The condenser coil 19 is connected to the settling tank coil 16 through a connecting pipe 20. The fine filter 6 is equipped with a filter plate 17 inside, and a rotating scraper 18 is located below the filter plate 17. The upper edge of the rotating scraper 18 is tangent to the lower edge of the filter plate 17. The fine filter 6 has a horizontally arranged ceramic filter plate 17 with a 0.5μm pore size. The upper edge of the polytetrafluoroethylene rotating scraper 18 is tangent to the lower edge of the filter plate. The rotation speed is adjustable. It has a bottom feed, a top discharge, and a bottom impurity discharge outlet. The ceramic filter plate has a uniform pore size, intercepting residual catalyst and ensuring liquid phase purity. The rotating scraper cleans scale in real time, avoiding filter plate clogging, maintaining a stable filtration flow, and reducing the number of downtime cleanings. The centrifugal separator 5 is connected to the fine filter 6 via a pipe located below the filter plate 17, and the coarse distillation column 7 is connected to the fine filter 6 via a pipe located above the filter plate 17. The top of the coarse distillation column 7 is connected to the condenser 9 via a vacuum pump.

[0025] The above-mentioned fatty amine discharge separation and recovery system includes the following steps during operation: (1) Open the discharge valve of the reactor 1 and discharge the fatty amine mixture through the connecting pipe 20 into the pre-filter 2. In the pre-filter 2, large-particle mechanical impurities are intercepted by the inclined baffle 13, the recessed collection box 12 and the filter screen 11. After pretreatment, the material enters the horizontal separator 3 through the connecting pipe 20. Control the temperature and pressure in the horizontal separator 3 and separate the gas phase and liquid phase with the help of the wire mesh demister 14 in the horizontal separator 3. (2) The liquid phase separated by the horizontal separator 3 is introduced into the conical bottom stirred settling tank 4 through the connecting pipe 20. The stirrer 15 of the conical bottom stirred settling tank 4 is turned on, and the coolant from the condenser 9 is introduced through the coolant inlet pipe 21. The coolant flows in the settling tank coil 16 to maintain the temperature in the conical bottom stirred settling tank 4, which promotes the aggregation of colloidal catalyst and its deposition at the bottom of the cone. The clear liquid is discharged through the connecting pipe 20. The discharged clear liquid enters the centrifugal separator 5 through the connecting pipe 20, and the larger particle size catalyst is separated by high-speed centrifugation. The liquid phase separated by the centrifugal separator 5 passes through the connecting pipe 20 and then through the fine filter 6. The filter plate 17 and the rotating scraper 18 in the fine filter 6 work together to intercept the residual catalyst and ensure that the catalyst content in the liquid phase meets the standard. (3) The liquid phase filtered by the fine filter 6 enters the coarse distillation column 7 through the connecting pipe 20. The floating valve column structure of the coarse distillation column 7 separates the low-boiling substances, crude secondary amine and high-boiling substances. The low-boiling substances and crude secondary amine are discharged through the connecting pipe 20 respectively. The discharged crude secondary amine is sent to the precision distillation column 8 through the connecting pipe 20. The corrugated packing of the precision distillation column 8 is used for deep purification to obtain qualified secondary amine product. The low-boiling substances at the top of the coarse distillation column 7 and the precision distillation column 8 are introduced into the condenser 9 through the connecting pipe 20 and the vacuum pump. The coolant is introduced through the coolant inlet pipe 21. The coolant flows in the coil 19 of the condenser and condenses the low-boiling substances into liquid phase. (4) The low-boiling liquid phase in the condenser 9 is introduced into the backwash filter 10 through the connecting pipe 20 to remove trace solid impurities. The filter element of the backwash filter 10 is rinsed regularly to maintain the flow rate. The raw material filtered by the backwash filter 10 enters the adsorption tower 22 through the connecting pipe 20. The high-boiling substances and water are removed by the adsorption of activated alumina and molecular sieve in the adsorption tower 22. The raw material purified by the adsorption tower 22 is introduced into the reactor 1 through the connecting pipe 20 and the transfer pump, and mixed with the fresh raw material to participate in the next batch of reaction.

Claims

1. A system for separating and recovering a fatty amine discharge, characterized by, The system includes a reactor (1), which is connected to a horizontal separator (3) via a pre-filter (2). The horizontal separator (3) is connected to a centrifugal separator (5) via a conical bottom stirred settling tank (4). The centrifugal separator (5) is connected to a precision distillation column (8) via a coarse distillation column (7). The top of the precision distillation column (8) is connected to a condenser (9) via a vacuum pump.

2. The fatty amine outtake separation recovery system of claim 1, wherein, A fine filter (6) is provided between the centrifugal separator (5) and the crude distillation column (7). The condenser (9) is connected to the reactor (1) through the adsorption column (22). A backwash filter (10) is provided between the condenser (9) and the adsorption column (22).

3. The fatty amine outtake separation and recovery system of claim 1, wherein, The pre-filter (2) is equipped with a filter screen (11) inside. The filter screen (11) and the side near the reactor (1) are equipped with a recessed collection box (12). An inclined baffle (13) is provided above the recessed collection box (12). The horizontal separator (3) is equipped with a wire mesh demister (14).

4. The fatty amine outfeed separation and recovery system of claim 3, wherein, The recessed collection box (12) and the inclined baffle (13) are both located inside the pre-filter (2).

5. The fatty amine outtake separation recovery system of claim 1, wherein, The conical bottom stirring settling tank (4) is equipped with an agitator (15) inside, and a settling tank coil (16) is provided on the outside of the agitator (15). The condensing tank (9) is equipped with a condensing tank coil (19) inside, and a coolant inlet pipe (21) is connected to the condensing tank coil (19). The condensing tank coil (19) is connected to the settling tank coil (16) through a connecting pipe (20).

6. The fatty amine outtake separation recovery system of claim 2, wherein, The fine filter (6) is provided with a filter plate (17) inside, and a rotating scraper (18) is provided below the filter plate (17). The upper edge of the rotating scraper (18) is tangent to the lower edge of the filter plate (17).

7. The fatty amine outfeed separation and recovery system of claim 6, wherein, The centrifugal separator (5) is connected to the fine filter (6) via a pipe located below the filter plate (17), and the coarse distillation column (7) is connected to the fine filter (6) via a pipe located above the filter plate (17). The top of the coarse distillation column (7) is connected to the condenser (9) via a vacuum pump.

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