Tail gas recovery treatment device for chloroacetic acid production
By designing the exhaust gas recovery and treatment device of the absorption tower and condenser, the problem of difficulty in recycling acetic acid and acid chloride in the exhaust gas in the chloroacetic acid production is solved, and efficient resource recycling and cost savings are achieved.
Patent Information
- Application Number
- CN202421966059.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-14
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-08-14
AI Technical Summary
During the production process of existing chloroacetic acid, acetic acid and acid chloride in the exhaust gas are difficult to recycle. The impurity acetic acid affects the quality of by-product hydrochloric acid, resulting in waste of resources and increased costs, making it difficult to achieve sustainable development of the enterprise.
A exhaust gas recovery and treatment device including an absorption tower and a condenser is designed, and a filler layer and a liquid distributor are used to realize the absorption of acetic acid and acid chloride, combined with a circulation pump and a liquid reservoir for recycling of the absorbent liquid, and a condenser is used to separate hydrogen chloride gas and acetic acid steam to improve recovery efficiency.
It has achieved efficient recycling and reuse of acetic acid and acid chloride in the exhaust gas, improved the purity of the by-product hydrogen chloride, reduced resource waste, reduced production costs, and promoted the sustainable development of the enterprise.
Smart Images
Figure CN223055367U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of chemical equipment, and particularly relates to a tail gas recovery and treatment device for chloroacetic acid production. Background Art
[0002] Aminoacetic acid is commonly known as glycine and glucosamine, odorless, with a special sweet taste, easily soluble in water, slightly soluble in methanol and ethanol, and almost insoluble in acetone and ether; aminoacetic acid is mainly used for non-toxic decarbonization of chemical fertilizers, medicine and pesticides, and is one of the raw materials for synthesizing glyphosate by the alkyl ester method. It can also be used as a raw material and preservative for cosmetics, and has a relatively wide market and application prospects. Therefore, the demand for aminoacetic acid is also increasing; at present, the domestic synthesis of aminoacetic acid mainly adopts the chloroacetic acid ammoniation method, using an aqueous solution of hexamethylenetetramine as a catalyst, synthesizing in an aqueous or alcoholic phase at normal temperature and pressure, and then obtaining the product through alcohol precipitation, filtration, refining and drying; however, in the process of producing aminoacetic acid, the tail gas generated during the preparation of its raw material chloroacetic acid is the main production problem of major enterprises. The components of the tail gas generated during chloroacetic acid production mainly include acetic acid, acyl chloride, hydrogen chloride, etc. In particular, acyl chloride is a catalyst in chloroacetic acid production and is difficult to recycle. At the same time, impurities such as acetic acid contained in the tail gas also cause quality problems for by-product hydrochloric acid. Due to quality problems, by-product hydrochloric acid is also difficult to fully utilize, resulting in a certain waste in resource utilization and cost consumption, and is not conducive to the sustainable development of enterprises; therefore, in order to solve the problem of tail gas treatment in chloroacetic acid production, recover acetic acid and acyl chloride in the tail gas, reduce impurities in by-product hydrochloric acid, and improve the quality of by-product hydrochloric acid, so as to achieve the purpose of saving energy and realizing resource recycling, it is necessary to develop a tail gas recovery and treatment device for chloroacetic acid production with a reasonable structural design, high absorption and treatment efficiency, and good effect. Content of the Utility Model
[0003] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a tail gas recovery and treatment device for chloroacetic acid production with a reasonable structural design, high absorption and treatment efficiency, and good effect.
[0004] The purpose of the present utility model is achieved as follows: A tail gas recovery and treatment device for chloroacetic acid production includes an absorption tower and a condenser. The absorption tower is overall columnar and is successively composed of a tower top, a tower body, and a tower bottom from top to bottom. Among them, an exhaust pipe is provided at the tower top, the tower body is limited between the tower top and the tower bottom, a circulating liquid feed port is provided at the upper end of the left side surface, a tail gas inlet is provided at the lower end of the left side surface, a packing layer is provided at the middle position inside, a liquid distributor is provided at the upper end inside, grid plates are provided at both the upper and lower ends of the packing layer, the liquid distributor is communicated with the circulating liquid feed port through a circulating absorption liquid pipe, a circulating absorption liquid flow outlet is provided on the tower bottom, and the circulating absorption liquid flow outlet is externally connected to a liquid storage tank. In the middle of the upper end of the liquid storage tank, an on-line thermometer is provided, an on-line liquid level gauge is vertically provided at the side end, and an absorption liquid discharge port is provided below. The absorption liquid discharge port is externally connected to a circulating pipe and a discharge pipe. Among them, the circulating pipe is communicated with the circulating liquid feed port of the absorption tower through a circulating pump, the discharge pipe is externally connected to a chloroacetic acid reaction kettle, and control valves are installed on both the circulating pipe and the discharge pipe; The condenser is located at the side end of the absorption tower, there are multiple condensers, which are successively vertically arranged, and a gas inlet is provided at the lower end of the left side surface of the condenser, a liquid outlet is provided at the bottom, and a gas outlet is provided at the top. The gas inlet is communicated with the exhaust pipe of the absorption tower, the liquid outlet is connected to the liquid storage tank through a diversion pipe, and the gas outlet is externally connected to an outlet pipe.
[0005] Further, a sandwich layer is provided on the inner wall of the liquid storage tank, a heat insulation layer is provided on the outer surface, and a cooling water inlet and a cooling water outlet are respectively communicated on both sides of the sandwich layer.
[0006] Further, the condenser is cooled by chilled brine, and the condenser is made of glass material.
[0007] Further, a hydrogen chloride on-line analyzer is installed on the outlet pipe.
[0008] Further, a backing plate is installed between the tower body and the tower top, and the tower body is limitedly connected to the tower bottom and the tower top through fixing bolts.
[0009] Advantages of the present utility model: By providing a tower top, a tower body, a tower bottom, an exhaust passage, a circulating liquid inlet, a tail gas inlet, a packing layer, a liquid distributor, and a circulating absorption liquid outlet, the tail gas inlet can be used to inject the tail gas generated during the production of chloroacetic acid into the absorption tower. Through the cooperation of the circulating liquid inlet and the liquid distributor, the absorption liquid can be evenly sprayed onto the packing layer. Thus, under the action of the self-gravity of the absorption liquid, during the process of moving downward from top to bottom on the surface of the packing layer, it comes into contact with the tail gas moving upward from bottom to top inside the absorption tower, achieving the absorption of acetic acid and acyl chloride in the tail gas. The exhaust passage can be used to transport hydrogen chloride gas and a small amount of acetic acid vapor in the tail gas to the inside of the condenser. The circulating absorption liquid outlet can be used to inject the absorption liquid that has completed the absorption of acetic acid and acyl chloride into the storage tank. At the same time, the entire packing layer of the present utility model is a Raschig ring, and the material is PP or PE. With this structure, the gas-liquid contact can be more sufficient, improving the absorption effect;
[0010] By providing a storage tank, an on-line thermometer, and an on-line liquid level gauge, the on-line thermometer and the on-line liquid level gauge can be used to facilitate the real-time detection of the quantity and temperature of the liquid inside the storage tank. By providing a circulating pipeline, a circulating pump, and a discharging pipeline, during actual use, the operator can adjust according to needs. That is, the absorption liquid can be recycled by the cooperation of the circulating pipeline and the circulating pump, or the absorption liquid that has completed the absorption of acetic acid and acyl chloride can be injected into the chloroacetic acid reaction kettle through the discharging pipeline for the reuse of acetic acid and acyl chloride;
[0011] By providing a condenser, the condenser can be used to condense acetic acid vapor, thereby separating hydrogen chloride gas and acetic acid vapor, improving the purity of hydrogen chloride gas. At the same time, the internal structure of the condenser is a serpentine structure, which can improve the condensation effect during its use. Generally, the present utility model has the advantages of reasonable structural design, high absorption and treatment efficiency, and good effect. Description of the Drawings
[0012] Figure 1 is the structural schematic diagram of the present utility model.
[0013] Figure 2 is the cross-sectional view of the front view of the absorption tower in the present utility model.
[0014] In the figure: 1. Absorption tower 11. Tower top 12. Tower body 13. Tower bottom 14. Exhaust pipeline 15. Circulating liquid inlet 16. Tail gas inlet 17. Packing layer 18. Liquid distributor 19. Circulating absorption liquid outlet 2. Condenser 21. Gas inlet 22. Liquid outlet 23. Gas outlet 3. Storage tank 31. On-line thermometer 32. On-line liquid level gauge 33. Absorption liquid discharging port 4. Circulating pipeline 41. Circulating pump 5. Discharging pipeline 6. Outlet pipeline 61. Hydrogen chloride on-line analyzer. Detailed Embodiments
[0015] The present utility model will be further described below in conjunction with the accompanying drawings.
[0016] Embodiment: As shown in Figure 1 、 Figure 2 , a tail gas recovery and treatment device for chloroacetic acid production includes an absorption tower 1 and a condenser 2. The absorption tower 1 is overall columnar and is successively composed of a tower top 11, a tower body 12, and a tower bottom 13 from top to bottom. Among them, an exhaust pipe 14 is provided at the tower top 11. The tower body 12 is limitedly arranged between the tower top 11 and the tower bottom 13. A circulating liquid feed port 15 is provided at the upper end of the left side surface, a tail gas inlet 16 is provided at the lower end of the left side surface, a packing layer 17 is provided at the middle position inside, and a liquid distributor 18 is provided at the upper end inside. The packing layer 17 is a Raschig ring, and grid plates are provided at both its upper and lower ends. The liquid distributor 18 is communicated with the circulating liquid feed port 15 through a circulating absorption liquid pipe. A circulating absorption liquid outlet 19 is provided on the tower bottom 13, and the circulating absorption liquid outlet 19 is externally connected to a liquid storage tank 3. An on-line thermometer 31 is provided in the middle of the upper end of the liquid storage tank 3, an on-line liquid level gauge 32 is vertically provided on the side end, and an absorption liquid discharge port 33 is provided below. The absorption liquid discharge port 33 is externally connected to a circulating pipe 4 and a discharge pipe 5. Among them, the circulating pipe 4 is communicated with the circulating liquid feed port 15 of the absorption tower 1 through a circulating pump 41. The discharge pipe 5 is externally connected to a chloroacetic acid reaction kettle, and control valves are installed on both the circulating pipe 4 and the discharge pipe 5. The condenser 2 is located at the side end of the absorption tower 1, there are multiple condensers, which are successively arranged vertically, and the inside of the condenser 2 adopts a serpentine structure. A gas inlet 21 is provided at the lower end of the left side surface, a liquid outlet 22 is provided at the bottom, and a gas outlet 23 is provided at the top. The gas inlet 21 is communicated with the exhaust pipe 14 of the absorption tower 1. The liquid outlet 22 is connected to the liquid storage tank 3 through a diversion pipe, and the gas outlet 23 is externally connected to an outlet pipe 6.
[0017] A sandwich layer is provided on the inner wall of the liquid storage tank 3, and a heat insulation layer is provided on the outer surface. Both sides of the sandwich layer are respectively communicated with a cooling water inlet and a cooling water outlet. The condenser 2 is cooled by chilled brine, and the condenser 2 is made of glass material. With this structure, it is convenient to clearly observe the operation of the condenser 2. An on-line hydrogen chloride analyzer 61 is installed on the outlet pipe 6. A backing plate is additionally installed between the tower body 12 and the tower top 11, and the tower body 12 and the tower bottom 13, and the tower body 12 and the tower top 11 are both limitedly connected through fixing bolts.
[0018] When the utility model is in use, first, through the cooperation of the circulating liquid inlet 15 and the liquid distributor 18, the absorption liquid is evenly sprayed onto the packing layer 17. After that, the tail gas of chloroacetic acid production is injected into the absorption tower 1 through the tail gas inlet 16. Thus, during the process of moving from top to bottom on the surface of the packing layer 17 by the gravity of the absorption liquid itself, it comes into contact with the tail gas moving from bottom to top inside the absorption tower 1, so as to realize the absorption of acetic acid and acyl chloride in the tail gas. Then, the absorption liquid that has completed the absorption of acetic acid and acyl chloride is injected into the storage tank 3 through the circulating absorption liquid outlet 19. The hydrogen chloride gas and a small amount of acetic acid vapor in the tail gas continue to rise and are successively injected into the condenser 2 through the exhaust passage 14 and the gas inlet 21. Finally, the absorption liquid injected into the storage tank 3 can be stored in the storage tank 3 and used as needed later (that is, the absorption liquid can be injected into the absorption tower 1 again by the cooperation of the circulating pipeline 4 and the circulating pump 41 for recycling the absorption liquid, or the absorption liquid that has completed the absorption of acetic acid and acyl chloride can be injected into the chloroacetic acid reaction kettle through the discharging pipeline 5 for the reuse of acetic acid and acyl chloride). At the same time, the hydrogen chloride gas and a small amount of acetic acid vapor injected into the condenser 2 can, under the condensation effect of the condenser 2, the non-condensable gas hydrogen chloride is discharged through the gas outlet 23, and the acetic acid vapor is condensed into a liquid state and flows into the storage tank 3 through the liquid outlet 22. By adopting this structure, the utility model can realize the recycling and reuse of acetic acid and acyl chloride in the tail gas, and at the same time improve the purity of the by-product hydrogen chloride. Generally, the utility model has the advantages of reasonable structural design, high absorption and treatment efficiency, and good effect.
[0019] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or make equivalent replacements. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention.
Claims
1. An exhaust gas recovery and treatment device for chloroacetic acid production, comprising an absorption tower (1) and a condenser (2), characterized in that: The absorption tower (1) is columnar as a whole and is successively composed of a tower top (11), a tower body (12) and a tower bottom (13) from top to bottom. An exhaust pipe (14) is provided at the tower top (11). The tower body (12) is limited between the tower top (11) and the tower bottom (13). A circulating liquid inlet (15) is provided at the upper end of the left side surface, a tail gas inlet (16) is provided at the lower end of the left side surface, a packing layer (17) is provided at the middle position inside, and a liquid distributor (18) is provided at the upper end inside. The packing layer (17) is a Raschig ring, and grid plates are provided at both the upper end and the lower end. The liquid distributor (18) is connected to the circulating liquid inlet (15) through a circulating absorption liquid pipe. A circulating absorption liquid outlet (19) is provided on the tower bottom (13), and the circulating absorption liquid outlet (19) is externally connected to a liquid storage tank (3). An on-line thermometer (31) is provided in the middle of the upper end of the liquid storage tank (3), an on-line liquid level gauge (32) is vertically provided at the side end, and an absorption liquid discharging port (33) is provided below. The absorption liquid discharging port (33) is externally connected to a circulating pipe (4) and a discharging pipe (5). Among them, the circulating pipe (4) is connected to the circulating liquid inlet (15) of the absorption tower (1) through a circulating pump (41), the discharging pipe (5) is externally connected to a chloroacetic acid reaction kettle, and control valves are installed on both the circulating pipe (4) and the discharging pipe (5); The condenser (2) is located at the side end of the absorption tower (1), there are multiple condensers, which are successively arranged vertically, and the inside of the condenser (2) adopts a serpentine structure. A gas inlet (21) is provided at the lower end of the left side surface, a liquid outlet (22) is provided at the bottom, and a gas outlet (23) is provided at the top. The gas inlet (21) is connected to the exhaust pipe (14) of the absorption tower (1), the liquid outlet (22) is connected to the liquid storage tank (3) through a diversion pipe, and the gas outlet (23) is externally connected to an air outlet pipe (6).
2. The tail gas recovery and treatment device for chloroacetic acid production according to claim 1, characterized in that: A sandwich layer is provided on the inner wall of the liquid storage tank (3), a heat insulation layer is provided on the outer surface, and a cooling water inlet and a cooling water outlet are respectively connected to both sides of the sandwich layer.
3. The tail gas recovery and treatment device for chloroacetic acid production according to claim 1, characterized in that: The condenser (2) is cooled by chilled brine, and the condenser (2) is made of glass material.
4. The tail gas recovery and treatment device for chloroacetic acid production according to claim 1, characterized in that: A hydrogen chloride on-line analyzer (61) is installed on the air outlet pipe (6).
5. The tail gas recovery and treatment device for chloroacetic acid production according to claim 1, characterized in that: A backing plate is additionally installed between the tower body (12) and the tower top (11), and the tower body (12) is limitedly connected to the tower bottom (13) and the tower body (12) is limitedly connected to the tower top (11) through fixing bolts.