A methanol recovery rectification device for N-methylaniline production

Abstract

The utility model discloses a kind of methanol recovery rectification equipment for N-methylaniline production, including rectifying column one, the rectifying column one side middle part is provided with feed pipe, the feed pipe one end is connected with feed tray, the feed tray middle part is connected with liquid inlet pipe by infusion tube, nozzle is installed on the liquid inlet pipe. Advantageous effect lies in: the utility model is through the design of feed pipe, liquid inlet pipe, infusion tube and feed tray, after vaporization wastewater enters feed tray, can be transported to each nozzle by infusion tube, make vaporization waste liquid can be evenly contacted with packing tower, simultaneously cooperate the design of regular packing and bulk packing, can effectively guarantee the uniform distribution of liquid, can effectively avoid the formation of local retention zone, avoid material to stay in high temperature zone for too long, reduce the opportunity of polymer attachment accumulation, effectively avoid the situation of blockage, ensure the normal work of rectifying column.

Description

Technical Field

[0001] This utility model relates to the technical field of methanol recovery distillation equipment, specifically to a methanol recovery distillation equipment for the production of N-methylaniline. Background Technology

[0002] Methanol is an important chemical product. During methanol production, the distillation residue containing methanol discharged from the bottom of the distillation column is commonly referred to as methanol wastewater. Direct discharge of methanol wastewater into water bodies would cause serious pollution and damage to the environment. A common method for treating methanol wastewater is vaporization. Vaporization utilizes the low boiling point of alcohols, employing waste heat boilers commonly used in production as a heat source to vaporize the low-boiling-point organic compounds in the wastewater. The vaporized wastewater is then fed into a gasifier to produce feed gas, achieving the dual purpose of treating wastewater and recovering feedstock.

[0003] Existing methanol recovery distillation equipment for N-methylaniline production utilizes the differences in volatility of the components in the mixture to perform multiple partial vaporizations and partial condensations of the reaction liquid generated during the N-methylaniline production reaction within the column, thereby separating the components. Although the above method can achieve methanol recovery distillation, the trace amounts of high-boiling-point N-methylaniline in the feed will polymerize and coke on the trays, downcomers, or receiving pans after entering the stripping section, gradually clogging the liquid passages. This leads to increased pressure in the distillation column, decreased distillation capacity, and requires frequent cleaning, affecting the normal operating efficiency of the unit. Utility Model Content

[0004] (a) Technical problems to be solved The technical problem to be solved by this utility model is to provide a methanol recovery distillation device for the production of N-methylaniline that can effectively prevent clogging, based on the current state of the technology.

[0005] (II) Technical Solution This utility model is achieved through the following technical solution: This utility model proposes a methanol recovery distillation device for N-methylaniline production, including a distillation column one, a feed pipe provided in the middle of one side of the distillation column one, a feed tray connected to one end of the feed pipe, a liquid inlet pipe connected to the middle of the feed tray through a liquid delivery pipe, a nozzle installed on the liquid inlet pipe, a condenser one connected to the top of one side wall of the distillation column one through a reflux pipe, and a distillation column two connected to the bottom of the condenser one through a collection pipe one. Distillation columns one and two are both provided with a rectification section at their upper ends, and a stripping section is provided at the lower end of the rectification section. Both the rectification section and the stripping section are equipped with packed towers. The top of the packed tower is provided with an upper baffle plate, the bottom of the packed tower is provided with a lower baffle plate, and the bottom of the packed tower is provided with both bulk packing and structured packing.

[0006] Furthermore, the second distillation column is connected to the second condenser via the reflux pipe, and the second condenser is provided with a second collection pipe on one side of its bottom end. The bottom of one side wall of the first distillation column is connected to the first reboiler, and the bottom of one side wall of the second distillation column is connected to the second reboiler. The bottom of the first reboiler is connected to the first distillation column via a waste liquid pipe, and the bottom of the second reboiler is connected to the second distillation column via a recovery pipe.

[0007] Furthermore, the first condenser is plugged into the first distillation column, and the second collection pipe is flanged into the second condenser.

[0008] Furthermore, the first reboiler is connected to the first distillation column, the second reboiler is connected to the second distillation column, the waste liquid pipe is flanged to both the first reboiler and the first distillation column, and the recovery pipe is flanged to both the second reboiler and the second distillation column.

[0009] Furthermore, the feed pipe is inserted into the first distillation column, the feed tray is connected to both the first and second distillation columns via slots, and the feed pipe is connected to the delivery pipe flange.

[0010] Furthermore, the infusion pipe is connected to the inlet pipe, the nozzle is connected to the inlet pipe, and the packed tower is connected to the rectification section and the stripping section by slots.

[0011] Furthermore, both the upper and lower partitions are inserted into the packed tower, and the structured packing and the bulk packing are connected to the slots of the packed tower.

[0012] (III) Beneficial Effects Compared with the prior art, this utility model has the following advantages: Through the design of the feed pipe, liquid inlet pipe, liquid delivery pipe, and feed tray, the vaporized wastewater can be transported to each nozzle by the liquid delivery pipe after entering the feed tray. This allows the vaporized wastewater to contact the packed tower evenly. At the same time, the combination of regulated packing and bulk packing effectively ensures uniform liquid distribution, avoids the formation of local stagnation zones, prevents materials from staying in the high-temperature zone for too long, reduces the chance of polymer adhesion and accumulation, effectively avoids clogging, and ensures the normal operation of the distillation tower. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a methanol recovery distillation device for N-methylaniline production according to the present invention; Figure 2 This is a schematic diagram of the feed tray in a methanol recovery distillation device for N-methylaniline production according to the present invention.

[0014] The annotations in the attached figures are explained as follows: 1. Rectifying section; 2. Feed pipe; 3. Distillation column one; 4. Stripping section; 5. Condenser one; 6. Reflux pipe; 7. Outlet pipe one; 8. Distillation column two; 9. Reboiler one; 10. Waste liquid pipe; 11. Condenser two; 12. Outlet pipe two; 13. Reboiler three; 14. Recovery pipe; 15. Packed column; 16. Bulk packing; 17. Feed tray; 18. Liquid inlet pipe; 19. Upper baffle; 20. Structured packing; 21. Lower baffle; 22. Liquid delivery pipe; 23. Nozzle. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0016] like Figures 1-2 As shown in this embodiment, a methanol recovery distillation device for N-methylaniline production includes a distillation column 3. A feed pipe 2 is located in the middle of one side of the distillation column 3. One end of the feed pipe 2 is connected to a feed tray 17. A liquid inlet pipe 18 is connected to the middle of the feed tray 17 via a liquid delivery pipe 22. A nozzle 23 is installed on the liquid inlet pipe 18. A condenser 5 is connected to the top of one side wall of the distillation column 3 via a reflux pipe 6. The bottom of the condenser 5 is connected to a distillation column 8 via a collection pipe 7. A rectification section 1 is evenly distributed in the upper part of both the distillation column 3 and the distillation column 8. A stripping section 4 is located at the lower end of the rectification section 1. Packed columns 15 are installed in both the rectification section 1 and the stripping section 4. An upper baffle 19 is installed at the top of the packed column 15. A lower baffle 21 is provided at the bottom. Bulk packing 16 and structured packing 20 are arranged at the bottom of the packed tower 15. Through the design of the feed pipe 2, liquid inlet pipe 18, liquid delivery pipe 22 and feed tray 17, after the vaporized wastewater enters the feed tray 17, it can be transported to each nozzle 23 by the liquid delivery pipe 22, so that the vaporized wastewater can be evenly contacted with the packed tower 15. At the same time, the design of structured packing 20 and bulk packing 16 can effectively ensure the uniform distribution of liquid, effectively avoid the formation of local stagnation zones, avoid the material staying in the high temperature zone for too long, reduce the chance of polymer adhesion and accumulation, effectively avoid clogging, and ensure the normal operation of the distillation tower.

[0017] like Figures 1-2 As shown, in this embodiment, distillation column 28 is connected to condenser 21 via reflux pipe 6. A collection pipe 22 is arranged on one side of the bottom of condenser 21. A reboiler 19 is connected to the bottom of one side wall of distillation column 3. A reboiler 23 is connected to the bottom of one side wall of distillation column 28. The bottom of reboiler 19 is connected to distillation column 3 via waste liquid pipe 10. The bottom of reboiler 23 is connected to distillation column 28 via recovery pipe 14.

[0018] like Figures 1-2 As shown, in this embodiment, condenser 5 is plugged into distillation column 3, and outlet pipe 12 is flanged into condenser 11. The design of condenser 5 and condenser 11 facilitates the cooling of steam, realizing the extraction of methanol, while ensuring suitable liquid phase reflux to maintain the thermal and material balance in distillation column 3 and distillation column 8.

[0019] like Figures 1-2 As shown, in this embodiment, reboiler 9 is connected to distillation column 3, reboiler 13 is connected to distillation column 8, waste liquid pipe 10 is flanged to both reboiler 9 and distillation column 3, and recovery pipe 14 is flanged to both reboiler 13 and distillation column 8. The design of reboiler 9 and reboiler 13 can provide the required heat to distillation column 3 and distillation column 8, causing the liquid at the bottom of the column to partially vaporize, generating rising steam, and driving the distillation process.

[0020] like Figures 1-2 As shown, in this embodiment, the feed pipe 2 is inserted into the distillation column 3, the feed tray 17 is connected to both the distillation column 3 and the distillation column 8 via a slot, and the feed pipe 2 is connected to the liquid delivery pipe 22 via a flange. The design of the distillation column 3 in conjunction with the distillation column 8 facilitates secondary distillation of the material and effectively ensures the completeness of methanol distillation by the device.

[0021] like Figures 1-2 As shown, in this embodiment, the infusion pipe 22 is inserted into the inlet pipe 18, the nozzle 23 is inserted into the inlet pipe 18, and the packed tower 15 is connected to the rectification section 1 and the stripping section 4 by slots. The infusion pipe 22 can transport the vaporized waste liquid through each nozzle 23 into the rectification tower 3 so as to heat it evenly and quickly.

[0022] like Figures 1-2 As shown, in this embodiment, both the upper partition 19 and the lower partition 21 are inserted into the packed tower 15, and the structured packing 20 and the bulk packing 16 are connected to the packed tower 15 through slots. The design of the upper partition 19 and the lower partition 21 provides protection for both ends of the packed tower 15, so as to facilitate the filling of the structured packing 20 and the bulk packing 16.

[0023] The specific implementation process of this embodiment is as follows: When using the device, it is necessary to install and fix distillation column 3, distillation column 8, reboiler 9, etc. The waste liquid pipe 10, recovery pipe 14, outlet pipe 7, and outlet pipe 12 of the device are connected to external equipment to enable the device to operate stably and continuously. An external power supply is also provided to the device. During operation, the vaporized waste liquid can enter each delivery pipe 22 through the feed pipe 2, realizing the delivery of liquid to the inlet pipe 18. Combined with the design of the nozzle 23, the liquid can be evenly distributed within the distillation column 3. The design of the regulated packing 20 and the bulk packing 16 effectively ensures uniform liquid distribution, effectively avoids the formation of local stagnation zones, prevents materials from staying in the high-temperature zone for too long, reduces the chance of polymer adhesion and accumulation, effectively avoids blockage, and ensures the normal operation of the distillation column. In distillation column 3… The liquid mixture is heated to partial vaporization, forming rising steam and descending liquid reflux. During the rising process, the steam and the descending liquid reflux come into contact on the trays or packing, resulting in mass and heat transfer. The lighter, more volatile components enter the rectification section 1 more, while the heavier, less volatile components remain in the stripping section 4 more. As the steam continues to rise and the liquid continues to fall, the rectification section 1 obtains high-purity light components, and the stripping section 4 obtains high-purity heavy components. Then, the condenser 5 condenses the liquid, and the reflux pipe 6 sends the condensed liquid back into the column. The outlet pipe 7 transfers the separated products to the rectification column 8 for secondary rectification, effectively ensuring the purification accuracy of methanol in the unit. The waste liquid pipe 10 can output the waste liquid in the rectification column 3. The design of the return water pipe 14 facilitates the return of the heavy components in the rectification column 8 to the rectification column 3 for secondary processing.

[0024] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A methanol recovery and distillation apparatus for N-methylaniline production, characterized in that: The distillation column includes a first distillation column (3), a feed pipe (2) is provided in the middle of one side of the first distillation column (3), one end of the feed pipe (2) is connected to a feed tray (17), the middle of the feed tray (17) is connected to an inlet pipe (18) through a liquid delivery pipe (22), a nozzle (23) is installed on the inlet pipe (18), the top of one side wall of the first distillation column (3) is connected to a first condenser (5) through a reflux pipe (6), the bottom end of the first condenser (5) is connected to a second distillation column (8) through a first outlet pipe (7), and the distillation column... The upper end of the first column (3) and the second column (8) are evenly provided with a rectification section (1), the lower end of the rectification section (1) is provided with a stripping section (4), and the rectification section (1) and the stripping section (4) are both equipped with a packed column (15). The top of the packed column (15) is provided with an upper baffle (19), the bottom of the packed column (15) is provided with a lower baffle (21), the bottom of the packed column (15) is provided with bulk packing (16), and the bottom of the packed column (15) is provided with structured packing (20).

2. The methanol recovery and distillation equipment for N-methylaniline production according to claim 1, characterized in that: The second distillation column (8) is connected to the second condenser (11) through the reflux pipe (6). The second condenser (11) has a second collection pipe (12) on one side of its bottom end. The first distillation column (3) is connected to the bottom of one side wall of the first distillation column (9). The second distillation column (8) is connected to the bottom of one side wall of the second distillation column (8). The bottom of the first reboiler (9) is connected to the first distillation column (3) through the waste liquid pipe (10). The bottom of the second reboiler (13) is connected to the second distillation column (8) through the recovery pipe (14).

3. The methanol recovery and distillation equipment for N-methylaniline production according to claim 2, characterized in that: The first condenser (5) is plugged into the first distillation column (3), and the second collection pipe (12) is flanged to the second condenser (11).

4. The methanol recovery and distillation equipment for N-methylaniline production according to claim 2, characterized in that: The first reboiler (9) is connected to the first distillation column (3), the second reboiler (13) is connected to the second distillation column (8), the waste liquid pipe (10) is flanged to both the first reboiler (9) and the first distillation column (3), and the recovery pipe (14) is flanged to both the second reboiler (13) and the second distillation column (8).

5. The methanol recovery and distillation equipment for N-methylaniline production according to claim 1, characterized in that: The feed pipe (2) is inserted into the first distillation column (3), the feed tray (17) is connected to the first distillation column (3) and the second distillation column (8) by a slot, and the feed pipe (2) is connected to the flange of the delivery pipe (22).

6. The methanol recovery and distillation equipment for N-methylaniline production according to claim 1, characterized in that: The infusion pipe (22) is inserted into the inlet pipe (18), the nozzle (23) is inserted into the inlet pipe (18), and the packed tower (15) is connected to the rectification section (1) and the stripping section (4) by slots.

7. The methanol recovery and distillation equipment for N-methylaniline production according to claim 1, characterized in that: The upper partition (19) and the lower partition (21) are both inserted into the packed tower (15), and the structured packing (20) and the bulk packing (16) are connected to the packed tower (15) by slots.

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