Methyl acetate VOCs tail gas treatment system

Abstract

The utility model relates to the technical field of tail gas treatment, in particular to a methyl acetate VOCs tail gas treatment system which comprises a methyl acetate tail gas inlet, a fresh water conveying port, a nitrogen conveying port and a steam conveying port, the methyl acetate tail gas inlet is communicated with a buffer tank through a pipeline, and the gas outlet end of the buffer tank is communicated with a water scrubber through a pipeline. The gas outlet end of the water washing tower is communicated with an adsorption tank group through a pipeline, the nitrogen conveying port and the steam conveying port are communicated with the adsorption tank group through pipelines, and the fresh water conveying port is communicated with a cooling water tank through a pipeline. And meanwhile, the tail gas treatment effect can be improved through a multi-stage treatment mode, so that the tail gas can better reach the emission standard, and the output of organic wastewater can be effectively reduced, thereby being more convenient for personnel to use.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas treatment, in particular to a methyl acetate VOCs tail gas treatment system. Background Art

[0002] Methyl acetate VOCs tail gas refers to methyl acetate waste gas containing volatile organic compounds (VOCs). VOCs are a class of volatile organic compounds that may cause harm to the environment and human health. Methyl acetate is a common organic compound, and its volatility causes it to be released in the tail gas. In industrial production and chemical processes, the volatile waste gas of methyl acetate needs to be controlled and treated to reduce the impact on the environment.

[0003] The existing methyl acetate VOCs tail gas is mostly treated by multi-stage washing, that is, the water-soluble acetone, acetaldehyde, methanol and other substances are absorbed by a low-temperature water washing spray tower to reduce the concentration of organic waste gas in the exhaust air. However, although the multi-stage washing method can achieve the effect of treating organic waste gas, it still has the following shortcomings:

[0004] The multi-stage washing method consumes a large amount of water resources, and the organic matter dissolved in the water needs to be separated through more devices later, resulting in a large amount of waste. In addition, the multi-stage washing method has limited effect on the treatment of organic waste gas, which makes it difficult to meet the exhaust emission standards and also produces a large amount of organic wastewater. Therefore, the existing methyl acetate VOCs exhaust gas treatment device still has certain shortcomings.

[0005] In summary, it is necessary to invent a methyl acetate VOCs tail gas treatment system. Utility Model Content

[0006] To this end, the utility model provides a methyl acetate VOCs tail gas treatment system to solve the problem that the treatment effect of multi-stage washing on organic waste gas is limited, which makes it difficult to meet the tail gas emission standards and also generates a large amount of organic wastewater.

[0007] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme: a methyl acetate VOCs tail gas treatment system, comprising a methyl acetate tail gas inlet, a fresh water delivery port, a nitrogen delivery port and a steam delivery port, the methyl acetate tail gas inlet is connected to a buffer tank through a pipeline, the gas outlet end of the buffer tank is connected to a water washing tower through a pipeline, the gas outlet end of the water washing tower is connected to an adsorption tank group through a pipeline, the nitrogen delivery port and the steam delivery port are both connected to the adsorption tank group through a pipeline, and the fresh water delivery port is connected to a cooling water tank through a pipeline.

[0008] Preferably, the gas outlet end of the buffer tank is connected to a condensate tank through a pipeline, a condenser c is provided in the pipeline between the buffer tank and the condensate tank, the gas outlet end of the condensate tank is connected to a water washing tower through a pipeline, and a condenser b is provided between the condensate tank and the water washing tower through a pipeline.

[0009] Preferably, the top gas outlet of the water scrubber is connected to the gas inlet of the adsorption tank group through a pipeline, and the waste liquid discharge ends in the buffer tank and the water scrubber are discharged outside the system through a waste liquid pipe.

[0010] Preferably, the discharge end of the condensate tank is connected to the solvent tank through a pipeline, the other end of the solvent tank is connected to the liquid separator tank through a pipeline, the other end of the liquid separator tank is connected to the cooling water tank through a pipeline, the air inlet end of the cooling water tank is connected to the condenser d through a pipeline, the air inlet end of the condenser d is connected to the exhaust end of the heat exchanger through a pipeline, and the air inlet end of the heat exchanger is connected to the steam discharge end of the adsorption tank group through a pipeline.

[0011] Preferably, the drainage end of the cooling water tank is connected to a water pump, the delivery end of the water pump is connected to the spray system in the adsorption tank group through a pipeline, and the bottom drainage port of the adsorption tank group is connected to the cooling water tank through a pipeline.

[0012] Preferably, the steam delivery port is connected to a pressure reducer through a pipeline, the exhaust end of the pressure reducer is connected to the steam inlet pipe port of the adsorption tank group through a pipeline, and the nitrogen delivery port is connected to the steam inlet pipe port through a pipeline.

[0013] Preferably, the exhaust gas discharge end of the adsorption tank group is connected to an electric heater through a pipeline, a catalytic combustion bed is arranged in the electric heater, the gas outlet end of the electric heater is connected to a catalytic combustion chamber through a pipeline, and the exhaust end of the catalytic combustion chamber is connected to an exhaust pipe through a pipeline.

[0014] The beneficial effects of the utility model are:

[0015] In the utility model, the tail gas to be treated is first collected through the methyl acetate tail gas inlet, and the organic waste can be filtered through the condensation of condenser b and condenser c, and then the tail gas is washed and adsorbed twice through the cooperation of the water washing tower and the adsorption tank group, and the organic waste gas after the adsorption treatment can be finally discharged after being treated by combustion. Compared with the existing multi-stage washing method, this system can effectively reduce the water consumption when treating the tail gas, and at the same time, the multi-stage treatment method can improve the treatment effect of the tail gas, so that the tail gas can better meet the emission standards, and can also effectively reduce the amount of organic wastewater generated, so that it is more convenient for personnel to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a schematic diagram of the overall system structure of the utility model;

[0017] Figure 2 For this utility model Figure 1 A schematic diagram of the enlarged structure of part A;

[0018] Figure 3 For this utility model Figure 1 A schematic diagram of the enlarged structure of part B;

[0019] Figure 4 For this utility model Figure 1 A schematic diagram of the enlarged structure of the middle C part;

[0020] Figure 5 For this utility model Figure 1 Schematic diagram of the enlarged structure of part D.

[0021] In the figure: 100, buffer tank; 200, condensate tank; 300, water washing tower; 310, condenser a; 320, condenser b; 321, condenser c; 400, methyl acetate tail gas inlet; 500, fresh water delivery port; 600, nitrogen delivery port; 700, steam delivery port; 710, exhaust pipe; 720, electric heater; 800, adsorption tank group; 900, solvent tank; 910, separator tank; 920, heat exchanger; 930, cooling water tank; 940, condenser d. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0023] Refer to the attached Figure 1-5The methyl acetate VOCs tail gas treatment system provided by the utility model comprises a methyl acetate tail gas inlet 400, a fresh water delivery port 500, a nitrogen delivery port 600 and a steam delivery port 700. The methyl acetate tail gas inlet 400 is connected to a buffer tank 100 through a pipeline. The buffer tank 100 is provided to buffer and depressurize the methyl acetate VOCs tail gas input from the methyl acetate tail gas inlet 400. The gas outlet of the buffer tank 100 is connected to a water washing tower 300 through a pipeline. The water washing tower 300 is provided to wash the methyl acetate VOCs tail gas and absorb the acetone, acetaldehyde, methanol and other substances that are easily soluble in water in the tail gas. The gas outlet of the water washing tower 300 is connected to an adsorption tank group 800 through a pipeline. The adsorption tank group 800 is provided mainly by providing The resin column disposed therein absorbs the waste gas discharged from the water washing tower 300, thereby further reducing the concentration of the discharged waste gas. The nitrogen delivery port 600 and the steam delivery port 700 are both connected to the adsorption tank group 800 through a pipeline, and the nitrogen delivery port 600 and the steam delivery port 700 are mainly provided for the subsequent purification of the resin column in the adsorption tank group 800 so that it can be used multiple times. The fresh water delivery port 500 is connected to the cooling water tank 930 through a pipeline, and the drainage end of the cooling water tank 930 is connected to a water pump, and the delivery end of the water pump is connected to the spray system in the adsorption tank group 800 through a pipeline, and the bottom drainage port of the adsorption tank group 800 is connected to the cooling water tank 930 through a pipeline, and the cooling water tank 930 is provided for spraying and cooling the resin column when the resin column is purified later;

[0024] The gas outlet of the buffer tank 100 is connected to the condensate tank 200 through a pipeline. A condenser c321 is arranged in the pipeline between the buffer tank 100 and the condensate tank 200. The condensers b320 and c321 are arranged to cool and condense the incoming methyl acetate VOCs tail gas twice, and the condensers b320 and c321 will store the liquid produced by the condensation of the tail gas in the condensate tank 200. A liquid level gauge is arranged in the condensate tank 200. After a period of collection, the condensate is pumped out of the boundary. The gas outlet of the condensate tank 200 is connected to the water washing tower 300 through a pipeline. Methanol, acetaldehyde and acetone have good water solubility in the exhaust gas. The exhaust gas coming from the front end passes through a water washing tower with a top low The water washing tower 300 with warm water spray and low-temperature water circulation spray in the lower circulation section can effectively reduce the concentration of organic waste gas after the exhaust gas is discharged from the tower, and the use of low-temperature water spray can effectively reduce the heat of dissolution and reduce the processing pressure of the rear-end adsorption system. A condenser b320 is arranged between the condensate tank 200 and the water washing tower 300 through a pipeline. The top gas outlet end of the water washing tower 300 is connected to the air inlet end of the adsorption tank group 800 through a pipeline. The waste liquid discharge end in the buffer tank 100 and the water washing tower 300 is discharged outside the system through a waste liquid pipe, and the discharge end of the water washing tower 300 needs to be connected to the condenser a310, and the exhaust gas mixed in the discharged water is condensed by the condenser a310 to avoid the exhaust gas from escaping.

[0025] The discharge end of the condensate tank 200 is connected to the solvent tank 900 through a pipeline, and the other end of the solvent tank 900 is connected to the liquid separator 910 through a pipeline. The other end of the liquid inlet end of the liquid separator 910 is connected to the cooling water tank 930 through a pipeline, and the air inlet end of the cooling water tank 930 is connected to the condenser d940 through a pipeline. The air inlet end of the condenser d940 is connected to the exhaust end of the heat exchanger 920 through a pipeline, and the air inlet end of the heat exchanger 920 is connected to the steam exhaust end of the adsorption tank group 800 through a pipeline. Specifically, when the resin column in the adsorption tank group 800 is saturated with adsorption, it is necessary to use steam to resolve the esters and other substances adsorbed by the resin to achieve the resin. Reuse of fat, that is, delivering 0.09MPa steam through the steam delivery port 700 for heating, desorption, analysis and regeneration. Since the designed steam pressure is 0.09Mpa, the design of the resin column does not involve a pressure vessel, and the used steam will be heat-exchanged by the heat exchanger 920 and condensed by the cooling water tank 930 before entering the liquid separator 910, and the non-condensed steam will return to the front end for further processing. The nitrogen delivery port 600 is set to deliver nitrogen to the adsorption tank group 800, so as to purge the small amount of steam and non-condensable gas remaining in the adsorption tank group 800 with nitrogen, press out the residual steam, and continue to enter the heat exchanger 920 to collect the condensate;

[0026] The steam delivery port 700 is connected to a pressure reducer through a pipeline, the exhaust end of the pressure reducer is connected to the steam inlet port of the adsorption tank group 800 through a pipeline, the nitrogen delivery port 600 is connected to the steam inlet port through a pipeline, the exhaust gas discharge end of the adsorption tank group 800 is connected to an electric heater 720 through a pipeline, a catalytic combustion bed is arranged in the electric heater 720, the gas outlet end of the electric heater 720 is connected to a catalytic combustion chamber through a pipeline, and the exhaust end of the catalytic combustion chamber is connected to an exhaust pipe 710 through a pipeline. Specifically, the concentration of organic waste gas in the exhaust tail gas treated by two-stage adsorption has been greatly reduced. After catalytic combustion, the emission meets the standard. The principle is: the organic waste gas enters the combustion furnace under the action of the induced draft fan, and is burned and decomposed into water and carbon dioxide under the catalytic action of the precious metal catalyst. The waste gas is thus purified. Before the organic waste gas enters the catalytic combustion equipment, a small part of the air needs to be passed into the catalytic combustion bed. Under the action of the electric heater 720, the catalytic combustion bed is preheated. A temperature sensor is installed in the preheating room to monitor the temperature in the room. When the temperature reaches the reaction temperature of the catalyst, the organic waste gas is introduced into the catalytic combustion chamber by the induced draft fan, and the organic waste gas is oxidized and decomposed in a high temperature environment.

[0027] The use process of the utility model is as follows: first, the exhaust gas is collected from the buffer tank 100 through the methyl acetate exhaust gas inlet 400, and then part of the methyl acetate and other substances in the exhaust gas are condensed through the condenser c321 and enter the condensate tank 200, and the remaining exhaust gas enters the condensate tank 200 and enters the condenser b320, and the condensed substances also enter the condensate tank 200, and the exhaust gas from the condenser b320 enters the water washing tower 300, and the condensate tank 200 is provided with a liquid level meter. After collecting for a period of time, the condensate is pumped out of the boundary;

[0028] Methanol, acetaldehyde and acetone in the exhaust gas have good water solubility. The exhaust gas from the front end passes through the water washing tower 300 with low-temperature water spraying at the top and low-temperature water circulation spraying at the lower circulation section, which effectively reduces the concentration of organic waste gas after the exhaust gas leaves the tower. The use of low-temperature water spraying can effectively reduce the heat of dissolution and reduce the processing pressure of the rear-end adsorption system. The exhaust gas will then enter the adsorption tank group 800 through the pipeline, and the adsorption tank group 800 will adsorb the organic matter in the exhaust gas through the resin column until the resin column reaches saturation;

[0029] In order to achieve the reuse of resin, the saturated steam that has been decompressed to 0.09MPa enters from the top of the adsorption tank group 800 through the steam delivery port 700, and then enters the heat exchanger 920 directly after being discharged from the bottom, and then enters the cooling water tank 930 for further cooling and is discharged into the exhaust pipe 710. The non-condensed steam returns to the front end for further processing. The regeneration time is determined based on the temperature sensor at the inlet of the heat exchanger 920 showing a temperature of 100 degrees and maintained for 10-15 minutes, and the regeneration is completed;

[0030] After steam regeneration is completed, 20Nm3 / h of nitrogen is delivered to the top of the first column of the regeneration zone through the nitrogen delivery port 600, and then discharged from the bottom and continued to enter the heat exchanger 920. The compression and decompression time lasts for about 12 minutes. After the compression is completed, 1m 3 / h of fresh water enters from the top of a column in the regeneration zone for spray cooling, and the water discharged from the bottom directly enters the cooling water tank 930 for circulation cooling. The cooling time lasts for about 60 minutes. After cooling, nitrogen enters from the top of a column in the regeneration zone, and the water discharged from the bottom directly enters the condenser d940. The nitrogen dosage is 1 tank of resin volume, and the cooling time lasts for about 15 minutes. After completion, the resin column is left to stand and drain. After the resin column completes the drainage work, it is ready to enter the next adsorption;

[0031] The exhaust gas adsorbed by the adsorption tank group 800 will enter the combustion furnace through the induced draft fan. Under the catalytic action of the precious metal catalyst, it will be burned and decomposed into water and carbon dioxide, and the exhaust gas will be purified. Before the organic exhaust gas enters the catalytic combustion equipment, a small amount of air needs to be passed into the catalytic combustion bed. Under the action of the electric heater 720, the catalytic combustion bed is preheated. A temperature sensor is installed in the preheating room to monitor the temperature in the room. When the temperature reaches the reaction temperature of the catalyst, the organic exhaust gas is introduced into the catalytic combustion chamber by the induced draft fan. The organic exhaust gas is oxidized and decomposed in a high temperature environment and finally discharged through the exhaust pipe 710.

[0032] The above is only a preferred embodiment of the utility model. Any person skilled in the art may modify the utility model by using the above technical solution or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent replacement based on the technical solution of the utility model shall fall within the scope of protection claimed by the utility model.

Claims

1. Methyl acetate VOCs tail gas treatment system, characterized by: The invention comprises a methyl acetate tail gas inlet (400), a fresh water delivery port (500), a nitrogen delivery port (600) and a steam delivery port (700); the methyl acetate tail gas inlet (400) is connected to a buffer tank (100) via a pipeline; the gas outlet of the buffer tank (100) is connected to a water scrubber (300) via a pipeline; the gas outlet of the water scrubber (300) is connected to an adsorption tank group (800) via a pipeline; the nitrogen delivery port (600) and the steam delivery port (700) are both connected to the adsorption tank group (800) via a pipeline; and the fresh water delivery port (500) is connected to a cooling water tank (930) via a pipeline.

2. The methyl acetate VOCs tail gas treatment system according to claim 1, characterized in that: The gas outlet end of the buffer tank (100) is connected to a condensate tank (200) via a pipeline, a condenser c (321) is provided in the pipeline between the buffer tank (100) and the condensate tank (200), the gas outlet end of the condensate tank (200) is connected to a water washing tower (300) via a pipeline, and a condenser b (320) is provided between the condensate tank (200) and the water washing tower (300) via a pipeline.

3. The methyl acetate VOCs tail gas treatment system according to claim 2, characterized in that: The top gas outlet of the water washing tower (300) is connected to the gas inlet of the adsorption tank group (800) through a pipeline, and the waste liquid discharge ends in the buffer tank (100) and the water washing tower (300) are discharged outside the system through a waste liquid pipe.

4. The methyl acetate VOCs tail gas treatment system according to claim 2, characterized in that: The discharge end of the condensate tank (200) is connected to the solvent tank (900) via a pipeline, the other end of the solvent tank (900) is connected to the liquid separation tank (910) via a pipeline, the other end of the liquid separation tank (910) is connected to the cooling water tank (930) via a pipeline, the air intake end of the cooling water tank (930) is connected to the condenser d (940) via a pipeline, the air intake end of the condenser d (940) is connected to the exhaust end of the pipeline heat exchanger (920), and the air intake end of the heat exchanger (920) is connected to the steam exhaust end of the adsorption tank group (800) via a pipeline.

5. The methyl acetate VOCs tail gas treatment system according to claim 4, characterized in that: The drainage end of the cooling water tank (930) is connected to a water pump, the delivery end of the water pump is connected to the spray system in the adsorption tank group (800) through a pipeline, and the bottom drainage port of the adsorption tank group (800) is connected to the cooling water tank (930) through a pipeline.

6. The methyl acetate VOCs tail gas treatment system according to claim 1, characterized in that: The steam delivery port (700) is connected to a pressure reducer via a pipeline, the exhaust end of the pressure reducer is connected to the steam inlet port of the adsorption tank group (800) via a pipeline, and the nitrogen delivery port (600) is connected to the steam inlet port via a pipeline.

7. The methyl acetate VOCs tail gas treatment system according to claim 1, characterized in that: The exhaust gas discharge end of the adsorption tank group (800) is connected to an electric heater (720) via a pipeline, a catalytic combustion bed is arranged in the electric heater (720), the gas outlet end of the electric heater (720) is connected to a catalytic combustion chamber via a pipeline, and the exhaust end of the catalytic combustion chamber is connected to an exhaust pipe (710) via a pipeline.

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