Waste gas treatment device in acetic anhydride synthesis process

Abstract

The utility model relates to the technical field of acetic anhydride production, in particular to a waste gas treatment device in an acetic anhydride synthesis process, which comprises a waste gas treatment tank and a controller, a catalyst layer is arranged in the waste gas treatment tank, and a waste gas discharge port is arranged at the top of the waste gas treatment tank. Wherein the waste gas input pipe is provided with a sensor assembly used for monitoring the inlet amount of carbon monoxide, the oxygen input pipe is provided with an air pump, and when waste gas generated in the acetic anhydride synthesis process is treated, firstly, external waste gas enters the waste gas treatment tank through the waste gas input pipe; oxygen enters the waste gas treatment tank through the oxygen input pipe and is mixed in the waste gas treatment tank, carbon dioxide is generated under the catalytic action of the catalyst layer, and carbon monoxide is removed, so that the waste gas in the acetic anhydride production process is treated.

Description

Technical Field

[0001] The utility model relates to the technical field of acetic anhydride production, in particular to a waste gas treatment device in the process of acetic anhydride synthesis. Background Art

[0002] The existing acetic anhydride is mostly produced by the methyl acetate carbonyl process, and the production process is as follows: first, the primary reaction is to react methanol and acetic acid raw materials under the catalyst condition of concentrated sulfuric acid to generate methyl acetate and water, and then the secondary reaction is to react methyl acetate, methanol and carbon monoxide as raw materials under the condition of methyl iodide, rhodium catalyst or nickel catalyst to generate acetic anhydride and acetic acid.

[0003] In the above-mentioned process for producing acetic anhydride, the stage in which waste gas is generated is mainly the secondary reaction stage. The main harmful component in the waste gas is the carbon monoxide raw material that has not reacted completely. Since carbon monoxide is a colorless, odorless toxic gas, it seriously damages the surrounding environment. Therefore, it is necessary to design a waste gas treatment device in the acetic anhydride synthesis process to solve the above-mentioned problem. Utility Model Content

[0004] The utility model provides a waste gas treatment device in the process of acetic anhydride synthesis, so as to solve the problem that the waste gas in the existing acetic anhydride production process is directly discharged into the atmosphere, which will damage the environment.

[0005] The technical problem solved by the utility model is achieved by the following technical solutions:

[0006] A waste gas treatment device in an acetic anhydride synthesis process, comprising:

[0007] An exhaust gas treatment tank, wherein the exhaust gas treatment tank has a catalyst layer inside and an exhaust gas discharge port on the top;

[0008] An exhaust gas input pipe, the exhaust gas input pipe is connected to the interior of the exhaust gas treatment tank, and a sensor component for monitoring the amount of carbon monoxide entering is arranged on the exhaust gas input pipe;

[0009] An oxygen input pipe, the oxygen input pipe is connected to the interior of the exhaust gas treatment tank, and an air pump is provided on the oxygen input pipe;

[0010] A controller, wherein the input end of the controller is connected to the output end of the sensor component for monitoring the amount of carbon monoxide entering the exhaust gas treatment tank, and is used to obtain the amount of carbon monoxide entering the exhaust gas treatment tank. The output end of the controller is used to output a control signal, and the control signal is used to control the operating speed of the air pump, thereby controlling the oxygen supply of the oxygen input pipe to the exhaust gas treatment tank.

[0011] Preferably, the sensor assembly for monitoring the amount of carbon monoxide entering comprises a gas flow rate sensor and a carbon monoxide concentration sensor.

[0012] Preferably, a gas mixing chamber with a communication opening at the top is further provided on the inner bottom wall of the waste gas treatment tank, and opposite sides of the gas mixing chamber are respectively connected to the waste gas input pipe and the oxygen input pipe.

[0013] Preferably, it also includes a cleaning tank arranged at the input end of the waste gas input pipe, the input end of the cleaning tank is provided with a waste gas supply pipe, the waste gas supply pipe is provided with a waste gas supply pump, the output end of the waste supply pipe extending inside the cleaning tank is an aeration pipe, and the water level in the cleaning tank is not lower than the height of the aeration pipe.

[0014] Preferably, the aeration pipe is in a conical spiral shape.

[0015] Preferably, a water pump is also provided on the upper part of the cleaning tank, and a water supply pipe is provided at the output end of the water pump and extends to the interior of the cleaning tank. An annular water collecting chamber is provided at the output end of the water supply pipe, and a plurality of atomizing nozzles are circumferentially provided on the annular water collecting chamber.

[0016] The beneficial effect of the utility model is that the waste gas treatment tank with a catalyst layer can make the carbon monoxide in the waste gas generated in the production process of acetic anhydride react with oxygen under the action of the catalyst layer to generate carbon dioxide for removal, so as to achieve the removal of carbon monoxide in the waste gas. At the same time, a sensor for monitoring the amount of carbon monoxide entering, a controller and an air pump for controlling the air supply speed of the oxygen input pipe are arranged, so that the carbon monoxide can have sufficient oxygen to react with it when the reaction is removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the implementation scheme of the utility model or the technical scheme in the prior art, the drawings required for use in the implementation scheme or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation schemes of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 This is a three-dimensional structural diagram of the utility model:

[0019] Figure 2 It is a front view of the utility model;

[0020] Figure 3 It is a side view of the utility model;

[0021] Figure 4 It is a cross-sectional view of the utility model.

[0022] In the figure, 1. exhaust gas treatment tank; 2. exhaust gas input pipe; 3. oxygen input pipe; 4. controller; 5. gas flow rate sensor; 6. carbon monoxide concentration sensor; 7. exhaust gas discharge port; 8. catalyst layer; 9. air pump; 10. gas mixing chamber; 11. connecting port; 12. cleaning tank; 13. exhaust gas supply pipe; 14. exhaust gas supply pump; 15. aeration pipe; 16. water supply pipe; 17. water pump; 18. annular water collection chamber; 19. atomizing nozzle. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below with reference to specific illustrations.

[0024] refer to Figure 1-Figure 4 , a waste gas treatment device in the process of acetic anhydride synthesis, comprising a waste gas treatment tank 1 with a catalyst layer 8 (for catalyzing the reaction of carbon monoxide and oxygen to generate carbon dioxide) and a waste gas discharge port 7 on the top, and a controller 4, the waste gas treatment tank 1 is connected with a waste gas input pipe 2 and an oxygen input pipe 3, wherein the waste gas input pipe 2 is provided with a sensor component for monitoring the amount of carbon monoxide entering, and the oxygen input pipe 3 is provided with an air pump 9. When the waste gas generated in the process of acetic anhydride synthesis is treated, firstly, the external waste gas enters the waste gas treatment tank 1 through the waste gas input pipe 2, and the oxygen enters the waste gas treatment tank 1 through the oxygen input pipe 3. After mixing inside the waste gas treatment tank 1, carbon dioxide is generated through the catalytic action of the catalyst layer 8, so that carbon monoxide is removed. In order to avoid insufficient reaction of carbon monoxide, it is necessary to provide enough oxygen and Carbon monoxide reacts, a sensor assembly is set on the waste gas input pipe 2 to monitor the amount of carbon monoxide entering, and the amount of carbon monoxide entering the waste gas treatment tank 1 is transmitted to the controller 4. The controller 4 receives the signal from the output end of the sensor assembly according to its input end, and outputs a control signal at its output end. The control signal is used to control the running speed of the air pump 9 on the oxygen input pipe 3 to control the amount of oxygen provided by the oxygen input pipe 3 to the waste gas treatment tank 1, so as to ensure that carbon monoxide has sufficient oxygen to react per unit time, thereby achieving the removal of carbon monoxide in the waste gas generated in the production process of acetic anhydride. It should be further explained that the oxygen input pipe 3 can react with carbon monoxide by conveying pure oxygen, or by conveying air so that the oxygen contained in the air reacts with carbon monoxide. The method of conveying air has lower cost.

[0025] Furthermore, the sensor assembly for monitoring the amount of carbon monoxide entering includes a gas flow rate sensor 5 and a carbon monoxide concentration sensor 6. The gas flow rate sensor 5 can monitor the exhaust gas flow rate of the exhaust gas inlet pipe 2, and the carbon monoxide concentration sensor 6 can monitor the carbon monoxide concentration in the exhaust gas. The controller 4 combines the gas flow rate sensor 5 and the carbon monoxide concentration sensor 6 to calculate the amount of carbon monoxide entering the exhaust gas treatment tank 1 from the exhaust gas inlet pipe 2 per unit time, so that the operating speed of the air pump 9 on the oxygen inlet pipe 3 can be controlled according to the information. Since the oxygen concentration transported in the oxygen inlet pipe 3 is fixed, the pure oxygen concentration is 100%, and the oxygen content in the air is about 21%, it is only necessary to control the operating speed of the air pump 9 to control the amount of oxygen entering the exhaust gas treatment tank 1 per unit time.

[0026] Furthermore, a gas mixing chamber 10 with a connecting port 11 on the top is provided on the inner bottom wall of the exhaust gas treatment tank 1. The opposite sides of the gas mixing chamber 10 are respectively connected to the exhaust gas input pipe 2 and the oxygen input pipe 3. In order to ensure that the carbon monoxide in the exhaust gas can fully contact with oxygen, the gas mixing chamber 10 is provided to enable the carbon monoxide and oxygen to be fully mixed to ensure sufficient reaction of the carbon monoxide. The opposite sides of the gas mixing chamber 10 are respectively connected to the exhaust gas input pipe 2 and the oxygen input pipe 3, so that the exhaust gas and the air can collide with each other after entering the interior of the mixing chamber to achieve sufficient mixing of the gas.

[0027] Furthermore, it also includes a cleaning tank 12 arranged at the input end of the waste gas input pipe 2, the input end of the cleaning tank 12 is provided with a waste gas supply pipe 13, the waste gas supply pipe 13 is provided with a waste gas supply pump 14, the output end of the waste supply pipe is extended inside the cleaning tank 12 as an aeration pipe 15, the water level in the cleaning tank 12 is not lower than the height of the aeration pipe 15, because the secondary reaction of acetic anhydride is that methyl acetate, methanol and carbon monoxide are used as raw materials, and react under the conditions of iodomethane, rhodium catalyst or nickel catalyst to generate acetic anhydride and acetic acid, so there will be attached to the discharged waste gas A small amount of methyl acetate, methanol, acetic anhydride and acetic acid. In order to remove the methyl acetate, methanol, acetic anhydride and acetic acid attached to the exhaust gas, a cleaning tank 12 is set to clean the exhaust gas. The main principle is that methyl acetate, methanol, acetic anhydride and acetic acid are all soluble in water. The specific exhaust gas cleaning process is that the exhaust gas enters the interior of the cleaning tank 12 through the exhaust gas supply pump 14 and the exhaust gas supply pipe 13, and then is dispersed in the water of the cleaning tank 12 through the aeration pipe 15 to ensure that the exhaust gas can be fully cleaned, so that the methyl acetate, methanol, acetic anhydride and acetic acid soluble in water in the exhaust gas are removed.

[0028] Furthermore, in order to ensure that the exhaust gas is dispersed more fully, the aeration pipe 15 is in a conical spiral shape. The conical spiral aeration pipe 15 can fully disperse the exhaust gas in the cleaning tank 12 in a three-dimensional shape, thereby fully ensuring the contact area between the exhaust gas and water.

[0029] Furthermore, a water pump 17 is also provided on the upper part of the cleaning tank 12, and a water supply pipe 16 is provided at the output end of the water pump 17 and extends to the interior of the cleaning tank 12, and an annular water collecting chamber 18 is provided at the output end of the water supply pipe 16, and a plurality of atomizing nozzles 19 are circumferentially provided on the annular water collecting chamber 18. By connecting the water pump 17 to an external water source, water can be supplied to the interior of the annular water collecting chamber 18, and a plurality of atomizing nozzles 19 are provided on the annular water collecting chamber 18, which can atomize and spray water, thereby further removing the water-soluble components in the exhaust gas.

[0030] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A waste gas treatment device in the acetic anhydride synthesis process, characterized in that: include; An exhaust gas treatment tank (1), wherein the exhaust gas treatment tank (1) has a catalyst layer (8) inside and an exhaust gas discharge port (7) at the top; an exhaust gas input pipe (2), the exhaust gas input pipe being in communication with the interior of the exhaust gas treatment tank (1), the exhaust gas input pipe (2) being provided with a sensor assembly for monitoring the amount of carbon monoxide entering; an oxygen input pipe (3), the oxygen input pipe (3) being in communication with the interior of the waste gas treatment tank (1), and an air pump (9) being provided on the oxygen input pipe (3); A controller (4), wherein the input end of the controller (4) is connected to the output end of a sensor component for monitoring the amount of carbon monoxide entering the exhaust gas treatment tank (1), and the output end of the controller (4) is used to output a control signal, and the control signal is used to control the operating speed of the air pump (9), thereby controlling the amount of oxygen supplied to the exhaust gas treatment tank (1) by the oxygen input pipe (3).

2. The waste gas treatment device in the acetic anhydride synthesis process according to claim 1, characterized in that: The sensor assembly for monitoring the amount of carbon monoxide entering comprises a gas flow rate sensor (5) and a carbon monoxide concentration sensor (6).

3. The waste gas treatment device in the acetic anhydride synthesis process according to claim 1, characterized in that: A gas mixing chamber (10) with a communication opening (11) at the top is also provided on the inner bottom wall of the waste gas treatment tank (1), and opposite sides of the gas mixing chamber (10) are respectively connected to the waste gas inlet pipe (2) and the oxygen inlet pipe (3).

4. The waste gas treatment device in the acetic anhydride synthesis process according to claim 1, characterized in that: It also comprises a cleaning tank (12) arranged at the input end of the waste gas input pipe (2), the input end of the cleaning tank (12) being provided with a waste gas supply pipe (13), the waste gas supply pipe (13) being provided with a waste gas supply pump (14), the output end of the waste gas supply pipe extending inside the cleaning tank (12) being an aeration pipe (15), the water level in the cleaning tank (12) being not lower than the height of the aeration pipe (15).

5. The waste gas treatment device in the acetic anhydride synthesis process according to claim 4, characterized in that: The aeration pipe (15) is in a conical spiral shape.

6. The waste gas treatment device in the acetic anhydride synthesis process according to claim 4, characterized in that: A water pump (17) is also provided at the top of the cleaning tank (12); a water supply pipe (16) is provided at the output end of the water pump (17) and extends into the interior of the cleaning tank (12); an annular water collection chamber (18) is provided at the output end of the water supply pipe (16); and a plurality of atomizing nozzles (19) are circumferentially provided on the annular water collection chamber (18).

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