Formamide tail gas comprehensive utilization system

Abstract

The utility model provides a formamide tail gas comprehensive utilization system, which comprises a tail gas recovery pipe, one end of the tail gas recovery pipe is used for communicating with a tail gas outlet of a formamide production device; a tail gas inlet of the condensation recovery unit is communicated with one end, far away from the formamide production device, of the tail gas recovery pipe, and the condensation recovery unit is used for condensing and recovering tail gas entering the condensation recovery unit; a tail gas inlet of the washing tank is communicated with a tail gas outlet of the condensation recovery unit through a first pipeline, and the washing tank is used for washing tail gas entering the washing tank; and the two ends of the tail gas exhaust pipe are communicated with the tail gas outlet of the water washing box and the exhaust chimney respectively, and an induced draft fan is arranged on the tail gas exhaust pipe. According to the invention, the emission of pollutants in the tail gas is effectively reduced, the influence of the pollutants in the tail gas on the environment is reduced, and the economic benefits of enterprises are also improved.

Description

Technical Field

[0001] This application relates to the field of exhaust gas utilization technology, and in particular to a comprehensive utilization system for formamide exhaust gas. Background Technology

[0002] Formamide is a colorless, transparent liquid with an ammonia-like odor. It has wide applications in industry and scientific research. Specifically, in organic synthesis, formamide is often used as a raw material to synthesize compounds such as imidazoles, pyrimidines, caffeine, theophylline, and theobromine. It is also used as a raw material for dyes, fragrances, pigments, adhesives, textile auxiliaries, and paper treatment agents. As a solvent, formamide is widely used in the spinning of acrylonitrile copolymers, the manufacture of ion exchange resins, and the antistatic or conductive coating of plastic products. Furthermore, in the pharmaceutical field, formamide is used to prepare active pharmaceutical ingredients and as a solvent, reaction medium, or intermediate. In molecular biology, formamide is frequently used in nucleic acid hybridization experiments, such as denaturing polyacrylamide gel electrophoresis and human chromosome in situ hybridization.

[0003] Due to the wide range of applications mentioned above, formamide is produced in large quantities. However, the production process generates significant amounts of amination reaction tail gas, vacuum tail gas, and distillation tail gas, which contain various pollutants (methyl formate, methanol, and ammonia (NH3), etc.). Direct emission of these tail gases into the atmosphere would pollute the environment. Comprehensive utilization of these tail gases can effectively reduce pollutant emissions and their environmental impact. Furthermore, it can transform waste into valuable resources, improving resource efficiency. For example, by recovering methyl formate, methanol, and ammonia (NH3) from the tail gas, high-value-added chemicals such as formic acid and oxalate esters can be produced, thereby improving the economic benefits of enterprises. Therefore, this application proposes a comprehensive formamide tail gas utilization system. Utility Model Content

[0004] This application provides a formamide exhaust gas comprehensive utilization system to solve the technical problems described in the background art above.

[0005] To solve the above-mentioned technical problems, this application adopts the following technical solution:

[0006] This application provides a comprehensive utilization system for formamide exhaust gas, comprising:

[0007] A tail gas recovery pipe, one end of which is used to connect to the tail gas outlet of the formamide production unit;

[0008] A condensation and recovery unit is provided, wherein the tail gas inlet of the condensation and recovery unit is connected to the end of the tail gas recovery pipe away from the formamide production device, and is used to condense and recover the tail gas entering it.

[0009] A water washing tank, wherein the exhaust gas inlet of the water washing tank is connected to the exhaust gas outlet of the condensation recovery unit through a first pipe, for washing the exhaust gas entering the tank with water.

[0010] The exhaust pipe is connected at both ends to the exhaust outlet of the washing tank and the chimney, and is equipped with an induced draft fan.

[0011] Optionally, the formamide production device is equipped with a controller, and the exhaust pipe is equipped with a first flow regulating valve between the induced draft fan and the chimney;

[0012] The induced draft fan and the first flow regulating valve are both electrically connected to the controller.

[0013] Optionally, a gas sensor electrically connected to the controller is provided on the pipe body of the exhaust pipe near the water washing tank, and a second pipe is connected between the exhaust pipe and the first flow regulating valve, and the end of the second pipe away from the exhaust pipe is connected to the exhaust gas recovery pipe.

[0014] The second pipeline is equipped with a second flow regulating valve that is electrically connected to the controller.

[0015] Optionally, the condensation recovery unit includes a primary condensation tank, a secondary condensation tank, and a tertiary condensation tank connected in sequence via a third pipeline;

[0016] The tail gas inlet of the first-stage condenser is connected to the end of the tail gas recovery pipe away from the formamide production device, and the tail gas outlet of the third-stage condenser is connected to the tail gas inlet of the water washing tank through the first pipe.

[0017] The primary condenser, the secondary condenser, and the tertiary condenser are all connected to a condensate storage tank via condenser pipes.

[0018] Optionally, a vacuum pump is installed on each of the third pipes and the first pipe between the tertiary condenser and the washing tank.

[0019] Optionally, each of the condensate storage tanks is provided with a viewing window.

[0020] Optionally, a first water spray pipe is connected to the side wall of the washing tank near its top. The end of the first water spray pipe located outside the washing tank is used to connect to an external water source, and the end located inside the washing tank is connected to a first water spray head.

[0021] The first water spray pipe is located above the exhaust gas inlet on the water washing tank.

[0022] Optionally, the first water spray pipe extends along the length of the water washing tank, and multiple second water spray pipes are interleaved and connected to the pipe inside the water washing tank.

[0023] Each of the second water spray pipes extends along the width of the washing tank and is connected to a plurality of second water spray heads at equal intervals.

[0024] Optionally, the exhaust gas outlet of the water washing tank is connected to a gas-liquid separator via a fourth pipe, and the outlet of the gas-liquid separator is connected to the end of the exhaust gas pipe away from the chimney.

[0025] The formamide tail gas comprehensive utilization system provided in this application introduces the tail gas generated by the formamide production unit into a condensation recovery unit via a tail gas recovery pipe. The condensation recovery unit condenses and recovers pollutants (e.g., methyl formate, methanol, and ammonia (NH3)) from the formamide tail gas. The condensate from the recovered formamide tail gas can be used to produce high-value-added chemicals. This not only effectively reduces the emission of pollutants from the tail gas and mitigates its environmental impact but also improves the economic benefits for the enterprise. Furthermore, a water washing tank further washes away non-condensable gases generated during the condensation process in the condensation recovery unit, further reducing the formamide content in the tail gas and thus improving the treatment efficiency. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A flowchart of a formamide tail gas comprehensive utilization system provided in an embodiment of this application;

[0028] Figure 2 This is a schematic diagram of the structure of a formamide tail gas comprehensive utilization system provided in an embodiment of this application;

[0029] Figure 3 This is a schematic diagram of the structure of a formamide tail gas comprehensive utilization system provided in another embodiment of this application;

[0030] Figure 4 This is a schematic diagram of the structure of a formamide tail gas comprehensive utilization system provided in an embodiment of this application;

[0031] Figure 5 This is a schematic diagram of the internal structure of a washing tank provided in an embodiment of this application;

[0032] Figure 6 This is a schematic diagram of a first water spray pipe and a plurality of second water spray pipes that are interleaved and connected to the first water spray pipe, according to an embodiment of this application.

[0033] In the diagram: 100, exhaust gas recovery pipe; 101, first pipeline; 1011, vacuum pump; 102, second pipeline; 1021, second flow regulating valve; 103, third pipeline; 104, fourth pipeline; 1041, gas-liquid separator; 200, formamide production unit; 201, controller; 300, condensation recovery unit; 301, primary condenser tank; 302, secondary condenser tank; 303, tertiary condenser tank; 400, water washing tank; 401, first water spray pipe; 4011, external water source; 4012, first water spray head; 402, second water spray pipe; 4021, second water spray head; 500, exhaust gas discharge pipe; 501, induced draft fan; 502, first flow regulating valve; 503, gas sensor; 600, chimney; 700, condenser pipe; 701, condensate storage tank; 7011, viewing window. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0035] refer to Figures 1 to 6 This application provides a formamide exhaust gas comprehensive utilization system, comprising:

[0036] The tail gas recovery pipe 100 is used to connect one end of the tail gas recovery pipe 100 to the tail gas outlet of the formamide production unit 200. The formamide production unit 200 is used to produce formamide, and the tail gas in the formamide production process mainly consists of methyl formate, methanol and ammonia (NH3).

[0037] The condensation and recovery unit 300 has its tail gas inlet connected to the end of the tail gas recovery pipe 100 away from the formamide production unit 200. It is used to condense and recover the tail gas entering it. Specifically, by condensing and recovering pollutants (such as methyl formate, methanol, and ammonia (NH3)) in the tail gas generated during the formamide production process, the condensate of the recovered formamide tail gas can be used to produce high-value-added chemicals. This not only effectively reduces the emission of pollutants in the tail gas and reduces the impact of the pollutants in the tail gas on the environment, but also improves the economic benefits of the enterprise.

[0038] The water washing tank 400 has its exhaust gas inlet connected to the exhaust gas outlet of the condensation recovery unit 300 via the first pipe 101, and is used to wash the exhaust gas entering it. In particular, the water washing tank 400 washes the non-condensable gas in the condensation process of the condensation recovery unit 300, further reducing the content of formamide exhaust gas, thereby improving the treatment efficiency of formamide exhaust gas.

[0039] The exhaust pipe 500 is connected at both ends to the exhaust outlet of the washing tank 400 and the chimney 600, respectively, and is equipped with an induced draft fan 501. The induced draft fan 501 enables the flow of power between the exhaust gas recovery pipe 100, the condensation recovery unit 300, the washing tank 400, the exhaust pipe 500, and the chimney 600 in the formamide production unit 200.

[0040] The formamide tail gas comprehensive utilization system provided in this application, when the induced draft fan 501 is turned on, the tail gas generated by the formamide production unit 200 enters the condensation recovery unit 300 through the tail gas recovery pipe 100. The condensation recovery unit 300 condenses and recovers pollutants (e.g., methyl formate, methanol, and ammonia (NH3)) in the formamide tail gas. Non-condensable gases generated during the condensation process in the condensation recovery unit 300 (wherein, since the formamide tail gas contains pollutants such as methyl formate, methanol, and ammonia (NH3), the non-condensable gases generated during the condensation recovery process in the condensation recovery unit 300 are also recovered) are also recovered. During the condensation process of the formamide tail gas, non-condensable gases (such as methyl formate, methanol, and ammonia) may enter the water washing tank 400 through the first pipe 101. The water washing tank 400 washes the non-condensable gases generated during the condensation process in the condensation recovery unit 300, further reducing the content of formamide tail gas and thus improving the treatment efficiency. This ensures that as much formamide tail gas as possible is treated, allowing the emissions to meet emission standards, with only a very small amount of formamide tail gas discharged through the tail gas emission pipe 500 and the chimney 600. This application, through the comprehensive utilization of formamide tail gas, not only effectively reduces the emission of pollutants in the tail gas and mitigates their environmental impact, but also improves the economic benefits for the enterprise.

[0041] In some embodiments, reference Figure 2 , Figure 3 and Figure 4 The formamide production apparatus 200 in this application is equipped with a controller 201, and the exhaust pipe 500 is equipped with a first flow regulating valve 502 between the induced draft fan 501 and the chimney 600. The specifications and models of the controller 201, the induced draft fan 501 and the first flow regulating valve 502 can be selected according to actual needs, and this application does not specifically limit them.

[0042] The induced draft fan 501 and the first flow regulating valve 502 are both electrically connected to the controller 201.

[0043] In the above embodiments, the controller 201 controls the operating state (open or closed) of the induced draft fan 501 and the opening degree of the first flow regulating valve 502, thereby achieving effective operation of the formamide tail gas emission process and improving the efficiency of comprehensive utilization of formamide tail gas. Furthermore, the first flow regulating valve 502 can control the emission rate of formamide tail gas, making the comprehensive utilization process of formamide tail gas controllable.

[0044] In some embodiments, reference Figure 2 , Figure 3 and Figure 4 In this application, a gas sensor 503 electrically connected to a controller 201 is installed on the exhaust pipe 500 near the water washing tank 400. A second pipe 102 connects the exhaust pipe 500 to the induced draft fan 501 and the first flow regulating valve 502. The end of the second pipe 102 away from the exhaust pipe 500 is connected to the exhaust gas recovery pipe 100. The gas sensor 503 detects the concentrations of pollutants such as methyl formate, methanol, and ammonia (NH3) in the formamide exhaust gas and compares the detected concentration values ​​with preset concentration thresholds (which can be set according to actual needs, but are not specifically limited in this application). In addition, a second flow regulating valve 1021 electrically connected to the controller 201 is installed on the second pipe 102.

[0045] In the above embodiments, if the concentration value detected by the gas sensor 503 is greater than the preset concentration threshold, it indicates that the pollutant concentration in the formamide tail gas after condensation and water washing is still high and does not meet the emission standards. At this time, the controller 201 receives the signal transmitted by the gas sensor 503 and closes the first flow regulating valve 502 and opens the second flow regulating valve 1021. That is, the formamide tail gas treated by the water washing tank 400 enters the tail gas recovery pipe 100 through the tail gas emission pipe 500 and the second pipe 102, repeating the above-mentioned comprehensive utilization process of condensation recovery and water washing. If the concentration value detected by the gas sensor 503 is less than the preset concentration threshold, it indicates that the pollutant concentration in the formamide tail gas after condensation and water washing meets the emission standards. In other words, the formamide tail gas treated by the water washing tank 400 can be discharged through the tail gas emission pipe 500 and the chimney 600. The above process makes the overall utilization process of formamide tail gas more thorough and improves the efficiency of comprehensive utilization of formamide tail gas.

[0046] In some embodiments, reference Figure 2 and Figure 3 The condensation recovery unit 300 in this application includes a primary condenser 301, a secondary condenser 302, and a tertiary condenser 303 connected sequentially through a third pipe 103. Since the formamide tail gas mainly contains pollutants such as methyl formate, methanol, and ammonia (NH3), and the boiling point of methyl formate is 32℃, the boiling point of methanol is 64.7℃, and the boiling point of ammonia is -33.3℃, ​​methanol is condensed through the primary condenser 301, methyl formate is condensed through the secondary condenser 302, and ammonia is condensed through the tertiary condenser 303.

[0047] In addition, the tail gas inlet of the primary condenser 301 is connected to the end of the tail gas recovery pipe 100 away from the formamide production unit 200, and the tail gas outlet of the tertiary condenser 303 is connected to the tail gas inlet of the water washing tank 400 through the first pipe 101. Among them, pollutants such as methyl formate, methanol, and ammonia (NH3) in the formamide tail gas first enter the primary condenser 301 through the tail gas recovery pipe 100. The primary condenser 301 condenses the methanol in the formamide tail gas, while the methanol and ammonia (NH3) in the formamide tail gas, as well as the non-condensable methanol, are condensed. The formamide tail gas enters the secondary condenser 302 through the third pipe 103, where methyl formate is condensed. The non-condensable gases of methanol and methyl formate in the formamide tail gas enter the tertiary condenser 303 through the third pipe 103, where ammonia is condensed. Finally, the non-condensable gases of methanol, methyl formate, and NH3 enter the water washing tank 400 through the first pipe 101, where the non-condensable gases of methanol, methyl formate, and NH3 are washed, achieving thorough treatment of the formamide tail gas. The primary condenser 301, secondary condenser 302, and tertiary condenser 303 are all connected to the condensate storage tank 701 via condenser pipes 700.

[0048] In the above embodiments, condensed methanol is collected through a condensate storage tank 701 connected to the primary condenser 301, condensed methyl formate is collected through a condensate storage tank 701 connected to the secondary condenser 302, and condensed liquid ammonia is collected through a condensate storage tank 701 connected to the tertiary condenser 303. By reusing the collected methanol, methyl formate, and liquid ammonia, the formamide tail gas is comprehensively utilized, thereby improving the economic benefits of the enterprise.

[0049] In some embodiments, reference Figure 2 and Figure 3 In this application, a vacuum pump 1011 is installed on each of the third pipes 103 and the first pipe 101 between the tertiary condenser 303 and the washing tank 400. The vacuum pump 1011 is used to extract non-condensable gases from the primary condenser 301, the secondary condenser 302 and the tertiary condenser 303.

[0050] In some embodiments, each condensate storage tank 701 in this application is provided with a visual observation window 7011. The visual observation window 7011 facilitates the observation of the condensed methanol, methyl formate, and liquid ammonia collected in the condensate storage tank 701, and facilitates the monitoring of the condensation status of methyl formate, methanol, and ammonia (NH3) in the formamide tail gas.

[0051] In some embodiments, reference Figure 2 and Figure 3 as well as Figure 5 and Figure 6In this application, a first water spray pipe 401 is connected to the side wall near the top of the washing tank 400. The end of the first water spray pipe 401 located outside the washing tank 400 is connected to an external water source 4011, and the end located inside the washing tank 400 is connected to a first water spray head 4012. A water pump is provided on the pipe body of the first water spray pipe 401 located outside the washing tank 400. The water pump delivers water from the external water source 4011 to the washing tank 400 through the first water spray pipe 401.

[0052] The first water spray pipe 401 is located above the exhaust gas inlet of the water washing tank 400. This ensures that the water sprayed from the first water spray head 4012 makes full contact with the water entering the water washing tank 400 from the exhaust gas inlet, so that the water washing is as complete as possible.

[0053] In the above embodiment, water from the external water source 4011 enters the water washing tank 400 through the first water spray pipe 401 and the first water spray head 4012 to wash the exhaust gas entering the water washing tank 400 from the exhaust gas inlet on the water washing tank 400. This achieves further treatment of the non-condensable gas coming out of the condensation recovery unit 300, so that the concentration of various pollutants in the formamide exhaust gas is reduced as much as possible and meets the emission standards, thus avoiding the pollution of the environment by the formamide exhaust gas discharged through the chimney 600.

[0054] In some embodiments, reference Figure 5 and Figure 6 In this application, the first water spray pipe 401 is located inside the water washing tank 400 and its pipe body extends along the length of the water washing tank 400. Multiple second water spray pipes 402 are interlaced on its pipe body inside the water washing tank 400. The arrangement of multiple second water spray pipes 402 improves the water washing efficiency of formamide exhaust gas entering the water washing tank 400.

[0055] In addition, each second water spray pipe 402 extends along the width of the washing tank 400, and is connected to multiple second water spray heads 4021 at equal intervals. This ensures that the exhaust gas entering the washing tank 400 is thoroughly washed, greatly reducing the concentration of various pollutants in the formamide exhaust gas discharged from the chimney 600 into the atmosphere, thus avoiding environmental pollution. The number of second water spray pipes 402 and the number of second water spray heads 4021 on each second water spray pipe 402 can be set according to the situation, and this application does not impose specific limitations on them.

[0056] In some embodiments, reference Figure 3 In this application, the exhaust outlet of the water washing tank 400 is connected to a gas-liquid separator 1041 via a fourth pipe 104. The outlet of the gas-liquid separator 1041 is connected to the end of the exhaust pipe 500 away from the chimney 600.

[0057] In the above embodiments, the gas-liquid separator 1041 enables the recovery of condensate and the purification of the gas phase. During the gas-liquid separation process, the separated liquid can be collected and reused, while the gas is purified before being discharged, thereby reducing environmental pollution. Furthermore, since formamide tail gas contains multiple pollutants such as methyl formate, methanol, and ammonia (NH3), and each of these pollutants has a different liquefaction temperature, the condensation of formamide tail gas requires multi-stage condensation. The gas-liquid separator 1041 utilizes low-temperature gas to cool the gas from the previous stage, thus achieving greater energy efficiency. This design not only improves system efficiency but also reduces energy consumption.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A system for the comprehensive utilization of formamide tail gas, characterized in that, include: A tail gas recovery pipe (100), one end of which is used to connect to the tail gas outlet of the formamide production unit (200); A condensation recovery unit (300) is provided, wherein the tail gas inlet of the condensation recovery unit (300) is connected to the end of the tail gas recovery pipe (100) away from the formamide production device (200), and is used to condense and recover the tail gas entering it; A water washing tank (400) has its exhaust gas inlet connected to the exhaust gas outlet of the condensation recovery unit (300) via a first pipe (101) for washing the exhaust gas entering it. The exhaust pipe (500) is connected at both ends to the exhaust outlet of the water washing tank (400) and the chimney (600) respectively, and is equipped with an induced draft fan (501).

2. The formamide tail gas comprehensive utilization system according to claim 1, characterized in that, The formamide production device (200) is equipped with a controller (201), and the exhaust pipe (500) is provided with a first flow regulating valve (502) between the induced draft fan (501) and the chimney (600); The induced draft fan (501) and the first flow regulating valve (502) are both electrically connected to the controller (201).

3. The formamide tail gas comprehensive utilization system according to claim 2, characterized in that, A gas sensor (503) electrically connected to the controller (201) is provided on the pipe body of the exhaust pipe (500) near the water washing tank (400). A second pipe (102) is connected between the exhaust pipe (500) and the first flow regulating valve (502). The end of the second pipe (102) away from the exhaust pipe (500) is connected to the exhaust gas recovery pipe (100). The second pipe (102) is provided with a second flow regulating valve (1021) that is electrically connected to the controller (201).

4. The formamide tail gas comprehensive utilization system according to claim 1, characterized in that, The condensation recovery unit (300) includes a primary condenser (301), a secondary condenser (302), and a tertiary condenser (303) connected in sequence through a third pipe (103); The tail gas inlet of the primary condenser (301) is connected to the end of the tail gas recovery pipe (100) away from the formamide production device (200), and the tail gas outlet of the tertiary condenser (303) is connected to the tail gas inlet of the washing tank (400) through the first pipe (101). The primary condenser (301), the secondary condenser (302), and the tertiary condenser (303) are all connected to a condensate storage tank (701) via a condenser pipe (700).

5. The formamide tail gas comprehensive utilization system according to claim 4, characterized in that, A vacuum pump (1011) is provided on each of the third pipes (103) and the first pipe (101) between the third-stage condenser (303) and the washing tank (400).

6. The formamide tail gas comprehensive utilization system according to claim 4, characterized in that, Each of the condensate storage tanks (701) is provided with a viewing window (7011).

7. The formamide tail gas comprehensive utilization system according to claim 1, characterized in that, The washing tank (400) has a first water spray pipe (401) connected to the side wall near its top. The first water spray pipe (401) is connected to an external water source (4011) at one end outside the washing tank (400), and to a first water spray head (4012) at the other end inside the washing tank (400). The first water spray pipe (401) is located above the exhaust gas inlet on the water washing tank (400).

8. The formamide tail gas comprehensive utilization system according to claim 7, characterized in that, The first water spray pipe (401) extends along the length of the water washing tank (400) within the water washing tank (400), and multiple second water spray pipes (402) are interlaced and connected to the pipe within the water washing tank (400). Each of the second water spray pipes (402) extends along the width direction of the washing tank (400) and is connected to a plurality of second water spray heads (4021) at equal intervals.

9. The formamide tail gas comprehensive utilization system according to any one of claims 1 to 8, characterized in that, The exhaust outlet of the water washing tank (400) is connected to a gas-liquid separator (1041) via a fourth pipe (104). The outlet of the gas-liquid separator (1041) is connected to the end of the exhaust pipe (500) away from the chimney (600).

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