Combined device for absorbing and treating glyoxylic acid synthesis reaction tail gas

Abstract

The invention discloses a combined device for absorbing and treating glyoxylic acid synthesis reaction tail gas, and belongs to the technical field of chemical production devices and tail gas recycling. The device mainly comprises an absorption buffer tank, an A-stage absorption device, a B-stage absorption device, a C-stage absorption device, a D-stage absorption device, an induced draft fan, an activated carbon purification box, a harmless airflow outlet, a dilute nitric acid transfer tank and the like, according to the technical scheme, the combined device for absorbing and treating glyoxylic acid synthesis reaction tail gas effectively solves the problem of low absorption efficiency of a previous nitrogen oxide absorption device and the problem of low nitric acid content in absorption liquid, and is relatively beneficial to environmental protection and production cost control; the invention also has the characteristics of safe process, convenient operation and high production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production equipment and reaction tail gas recovery and reuse, and in particular relates to a combined device for absorbing and treating glyoxylic acid synthesis reaction tail gas. Background Art

[0002] Glyoxylic acid is an important organic synthesis intermediate, which is widely used in spices, medicines, pesticides, foods, varnish raw materials, dyes, plastic additives and other organic synthesis intermediates. It can also be used in vanillin, ethyl vanillin, mandelic acid, p-hydroxyphenylglycine, p-hydroxyphenylacetic acid, allantoin and other products.

[0003] The "glyoxal nitric acid oxidation method" is a relatively mature and relatively low-cost method for synthesizing glyoxylic acid. It is a process in which glyoxal is oxidized to glyoxylic acid by dilute nitric acid under the action of a composite catalyst. The oxidation process also produces a large amount of nitrogen oxides such as nitric oxide and nitrogen dioxide. X .

[0004] The main chemical reaction equations for the synthesis of glyoxylic acid by glyoxal nitric acid oxidation are as follows: 3CHO-CHO + 2HNO3→ 3CHO-COOH + 2NO↑+ H2O, 3CHO-COOH + 2HNO3 → 3HOOC-COOH + 2NO↑+ H2O, 2NO + O2 → 2NO2, NO + HNO3 → HNO2 + NO2.

[0005] In the prior art, in order to prevent the escape of nitrogen oxide reaction tail gas, most of the recovery and treatment methods adopt 6-stage spray water absorption and 2-stage alkali solution absorption. Due to the insufficient air supplement and slow and incomplete spray absorption in the production process, a 2-stage alkali solution absorption tower must be installed at the end of the tail gas absorption device to prevent nitrogen oxide NO X The sudden escape of nitrogen oxides will cause harm to the atmospheric environment. The continuous 6-stage water spray absorption and the terminal 2-stage alkali solution absorption device require a large space, equipment and resources. The sodium nitrate and sodium nitrite solutions generated by the terminal 2-stage alkali solution absorption must continue to be treated for harmless desalination. Therefore, it is necessary to innovate and improve the nitrogen oxide absorption treatment method and device in the prior art. Summary of the invention

[0006] In order to solve the above problems, the technical scheme of the present invention discloses a combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction. Its innovative points mainly include: 1. adding an air inlet at the front end of the reaction tail gas pipeline just out of the synthesis reactor to strengthen the conversion of nitrogen monoxide to nitrogen dioxide, so as to facilitate the absorption of nitrogen dioxide by water; 2. designing and installing an absorption buffer tank before the tail gas enters the absorption tower to slow down the high-speed tail gas flow for pre-absorption; 3. designing and installing a gas-liquid mixing ejector before the tail gas enters the absorption tower to force the absorption of nitrogen oxides before spraying absorption, and the absorption capacity of one gas-liquid mixing ejector for tail gas is equivalent to the effect of 3 to 4 spraying absorption towers; 4. designing and installing a built-in heat exchanger with cooling water in the absorption liquid tank to effectively cool down the absorption liquid that is rapidly heated after forced absorption by the gas-liquid mixing ejector, so as to ensure process safety and absorption effect; 5. The alkali solution spray absorption device at the end is replaced with a urea solution spray absorption device, and the absorption liquid whose main component remaining after the absorption reaction is water moves forward step by step, which is conducive to the comprehensive utilization of water resources. The combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention effectively solves the problems of low absorption efficiency and incomplete absorption of nitrogen oxide absorption devices in the past, and solves the problem of low nitric acid content in the absorption liquid, which is beneficial to environmental protection and production cost control; the present invention also has the characteristics of safe process, convenient operation and high production efficiency.

[0007] The technical solution of the present invention discloses a combined device for absorbing and treating the tail gas of a glyoxylic acid synthesis reaction, which comprises: an absorption buffer tank, an air inlet, an air purifier, an air flow disperser, a pure water control valve, an anti-entrainment damper, a liquid removal condenser, an A-class absorption device, an A-class absorption tower, an A-class absorption liquid tank, an A-class gas-liquid mixing ejector, an A-class spray control valve, a spray head in a tower, a high-position spray head, a liquid removal net, an A-class circulation pump, an A-class lifting valve, a B-class absorption device, a B-class absorption tower, a B-class absorption liquid tank, a B-class circulation pump, a B-class gas-liquid mixer, a B-class spray control valve, a B-class lifting valve, a C-class absorption device, a C-class absorption tower, a C-class absorption liquid tank, a tower inlet inclined pipe, a C-class circulation pump, a C-class lifting valve, a D-class absorption device, a D-class absorption tower, a D-class absorption A liquid tank, a D-class circulation pump, a D-class lifting valve, an induced draft fan, an activated carbon purification box, a harmless tail gas outlet, a dilute nitric acid transfer tank, a synthesis reactor, a reaction reflux condenser, and a reaction tail gas pipeline, characterized in that an air flow disperser is arranged inside the absorption buffer tank, three openings are arranged on the upper part of the absorption buffer tank, one side opening is connected to the reaction tail gas pipeline through the air flow disperser and is connected to the synthesis reactor, an air inlet is arranged on the reaction tail gas pipeline, the other side opening is connected to the pure water control valve, the middle opening is connected to the anti-entrainment damper and the liquid removal condenser in sequence upward through a pipeline, the liquid removal condenser is connected to the A-class gas-liquid mixing ejector of the A-class absorption device forward through a pipeline, a dilute nitric acid transfer pump is connected to the lower side of the absorption buffer tank, and the dilute nitric acid transfer pump is connected to the dilute nitric acid transfer pump. The pump is connected to the dilute nitric acid transfer tank through a dilute nitric acid transfer valve. The lower part of the A-class absorption device is an A-class absorption liquid tank. A-class absorption tower is installed directly above the absorption liquid tank. A built-in heat exchanger is arranged inside the A-class absorption liquid tank. A-class circulation pump is arranged at the lower part of the outer side of the A-class absorption liquid tank. A tower spray head is added in the middle of the A-class absorption tower, a high-position spray head is added in the upper part, and a liquid removal net is arranged on the top of the tower. A-class gas-liquid mixing ejector is arranged on the outer side of the middle of the A-class absorption tower and is connected forward to the tower spray head. The side opening of the A-class gas-liquid mixing ejector is connected to the reaction tail gas pipeline from the synthesis reactor. The A-class circulation pump is connected to the A-class gas-liquid mixing ejector and the high-position spray head upward through pipelines, and the A-class circulation pump is connected to the dilute nitric acid transfer tank through an A-class lifting valve. The top of the A-class absorption tower is connected to the B-class gas-liquid mixing ejector of the B-class absorption device through a pipeline. The structure of the B-class absorption device is exactly the same as that of the A-class absorption device. The lower part of the B-class absorption device is the B-class absorption liquid tank. The B-class absorption tower is installed directly above the B-class absorption liquid tank. The B-class gas-liquid mixing ejector is arranged on one side of the middle of the B-class absorption tower. The B-class circulation pump is arranged on the side of the lower part of the B-class absorption liquid tank. The B-class circulation pump is connected to the A-class absorption liquid tank through a B-class lifting valve. The top of the B-class absorption tower is connected to the tower inlet inclined pipe at the bottom of the C-class absorption tower of the C-class absorption device through a pipeline. The lower part of the C-class absorption device is the C-class absorption liquid tank. The C-class absorption tower is installed directly above the C-class absorption liquid tank. The tower inlet inclined pipe is arranged on the side of the lower part of the C-class absorption tower.The inlet inclined pipe is connected to the top of the B-class absorption tower through a pipeline. A C-class circulating pump is arranged on the lower side of the C-class absorption liquid tank. The C-class circulating pump is connected to the upper part of the C-class absorption tower through a pipeline. The C-class circulating pump is connected to the B-class absorption liquid tank through a C-class lifting valve. The top of the C-class absorption tower is connected to the D-class absorption tower of the D-class absorption device through a pipeline. The D-class absorption device has the same structure as the C-class absorption device. The lower part of the D-class absorption device is the D-class absorption liquid tank. The D-class absorption tower is installed directly above the D-class absorption liquid tank. A D-class circulating pump is arranged on the lower side of the D-class absorption liquid tank and is connected to the C-class absorption liquid tank through a pipeline and a D-class lifting valve. The top of the D-class absorption tower is connected to an induced draft fan. The induced draft fan is connected to the bottom of the activated carbon purification box through a pipeline. A harmless exhaust gas outlet is arranged on the top of the activated carbon purification box. The above-mentioned absorption devices at various levels and various components are organically combined to form a combined device for absorbing and treating the exhaust gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention, which can effectively absorb and treat the nitrogen oxide exhaust gas of the glyoxylic acid synthesis reaction.

[0008] Preferably, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention is characterized in that the anti-entrainment damper has a cylindrical or ellipsoidal appearance with conical protrusions at both ends, the main body diameter of the anti-entrainment damper is 2.5 to 3.0 times the diameter of the connected tail gas pipeline, the height is 80 to 100 cm, and the material is glass-lined or 904 stainless steel. The purpose of designing the anti-entrainment damper is to slow down and pre-absorb the high-speed airflow from the synthesis reactor to prevent the high-speed airflow from entraining the reaction materials and moving backward, thereby achieving efficient absorption of nitrogen oxide tail gas by the A-D absorption device.

[0009] Preferably, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention is characterized in that the air inlet is connected to an air purifier, and the air purifier is made of a PP tube with a length of 80 cm and a diameter of 100-125 mm, and 100-150 circular holes with an aperture of 10 mm are drilled on the surface of the PP tube, and the surface of the PP tube is covered with a single-layer filter cloth with an aperture of 100 mesh. The purpose of this design is to effectively prevent dust, flying debris and other impurities from entering the tail gas absorption system after the air is purified, thereby ensuring the quality of the dilute nitric acid obtained by tail gas absorption.

[0010] Preferably, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention is characterized in that the airflow disperser has an annular appearance and is welded and assembled from a hard PP pipe or PTFE pipe with a diameter of 40 to 50 mm, and its installation position is 50 to 60 cm away from the bottom of the absorption buffer tank. The purpose of this design is to ensure that the tail gas of nitrogen oxides can be evenly dispersed into the absorption liquid in the absorption buffer tank to achieve the purpose of efficient absorption.

[0011] Preferably, the combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to the technical solution of the present invention is characterized in that 150 to 200 circular holes with a diameter of 5.0 to 10 mm are opened on the downward half surface of the airflow disperser. The purpose of opening circular holes on the downward half surface is also to achieve efficient absorption of nitrogen oxide tail gas.

[0012] Preferably, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention is characterized in that the built-in heat exchanger is welded by a PP pipe with a diameter of 15 to 20 mm, and the heat exchange area is 40 to 50 m 2 The purpose of designing and installing a built-in heat exchanger for cooling is to reduce the large amount of heat generated by the forced absorption of exhaust gas by the gas-liquid mixing ejector, so as to ensure process safety and improve production efficiency.

[0013] Preferably, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention is characterized in that the inlet inclined pipe is at an angle of 30 to 60 degrees to the absorption tower, and the inlet inclined pipe extends 5.0 to 10 cm into the absorption tower. The purpose of this design is to prevent the spray liquid from entering the tail gas pipeline and causing local blockage or poor air flow.

[0014] Preferably, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention is characterized in that the liquid removal net is composed of 6 to 8 layers of acid-resistant stainless steel wire mesh, with a mass transfer area of ​​40 to 50 m 2 The purpose of this design is to ensure that the high-speed airflow does not carry the liquid material out of the absorption device, thereby ensuring that the nitrogen oxide tail gas is effectively absorbed inside the absorption tower.

[0015] The combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention has obvious beneficial effects in the following aspects: (1) adding an air inlet to the front tail gas pipeline can effectively enhance the conversion of nitrogen monoxide to nitrogen dioxide, which is beneficial to accelerating absorption, and installing an air purifier is beneficial to avoiding the introduction of impurities; (2) the design and installation of the absorption buffer tank can effectively reduce the speed of the high-speed tail gas flow for pre-absorption, which is very beneficial to the absorption of nitrogen oxides; 3. The design and installation of a gas-liquid mixing ejector can force the absorption of nitrogen oxides, which is very beneficial to the improvement of absorption effect and production efficiency; 4. The design and installation of a built-in heat exchanger in the absorption liquid tank can effectively cool down the absorption liquid that is rapidly heated after forced absorption by the gas-liquid mixing ejector, which is beneficial to process safety and improving production efficiency; 5. The step-by-step forward movement of the absorption liquid at the end can effectively ensure that a small amount of dilute nitric acid and pure water will not be wasted, which is very beneficial to the effective use of water resources and the reduction of energy consumption.

[0016] The combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention effectively solves the problems of low absorption efficiency and incomplete absorption of nitrogen oxide absorption devices in the past, and solves the problem of low nitric acid content in the absorption liquid, which is beneficial to environmental protection and production cost control; the present invention also has the characteristics of safe process, convenient operation and high production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and ordinary technicians in this field can also obtain other drawings based on these drawings.

[0018] Figure 1 The present invention discloses a process flow diagram and a planar structural diagram of a combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to the technical solution of the present invention.

[0019] Figure 1 Middle: Absorption buffer tank 01, air purifier 11, air inlet 12, air flow disperser 13, pure water control valve 14, anti-entrainment damper 15, liquid removal condenser 16, dilute nitric acid transfer pump 17, dilute nitric acid transfer valve 18, Class A absorption device 02, Class A gas-liquid mixing ejector 20, Class A absorption liquid tank 21, Class A absorption tower 22, Class A circulation pump 23, Class A spray control valve 24, tower spray head 25, high-position spray head 26, built-in heat exchanger 27, liquid removal net 28, Class A lifting valve 29, Class B absorption device 03, Class B absorption tower 31, Class B absorption liquid Tank 30, Class B circulation pump 32, Class B gas-liquid mixer 33, Class B spray control valve 35, Class B lifting valve 34, Class C absorption device 04, Class C absorption tower 41, Class C tower inlet inclined pipe 42, Class C absorption liquid tank 40, Class C circulation pump 43, Class C lifting valve 44, Class D absorption device 05, Class D absorption tower 51, Class D absorption liquid tank 50, Class D circulation pump 52, Class D lifting valve 53, induced draft fan 06, activated carbon purification box 07, harmless tail gas outlet 71, dilute nitric acid transfer tank 08, synthesis reactor 09, reaction reflux condenser 91, reaction tail gas pipeline 92. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following Figure 1 This specific implementation example is further described.

[0021] The combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation method comprises: an absorption buffer tank 01, an air purifier 11, an air inlet 12, an air flow disperser 13, a pure water control valve 14, an anti-entrainment damper 15, a liquid removal condenser 16, a dilute nitric acid transfer pump 17, a dilute nitric acid transfer valve 18, a class A absorption device 02, a class A gas-liquid mixing ejector 20, a class A absorption liquid tank 21, a class A absorption tower 22, a class A circulation pump 23, a class A spray control valve 24, a tower spray head 25, a high-position spray head 26, a built-in heat exchanger 27, a liquid removal net 28, a class A lifting valve 29, and a class B absorption device 02. Device 03, Class B absorption tower 31, Class B absorption liquid tank 30, Class B circulation pump 32, Class B gas-liquid mixer 33, Class B spray control valve 35, Class B lifting valve 34, Class C absorption device 04, Class C absorption tower 41, Class C tower inlet inclined pipe 42, Class C absorption liquid tank 40, Class C circulation pump 43, Class C lifting valve 44, Class D absorption device 05, Class D absorption tower 51, Class D absorption liquid tank 50, Class D circulation pump 52, Class D lifting valve 53, induced draft fan 06, activated carbon purification box 07, harmless tail gas outlet 71, dilute nitric acid transfer tank 08, synthesis reactor 09, reaction reflux condenser 91, reaction tail gas pipeline 92.

[0022] The combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation method is characterized in that an air flow disperser 13 is arranged inside the absorption buffer tank 01, and three openings are arranged on the upper part of the absorption buffer tank 01, one side opening is connected to the reaction tail gas pipeline 92 through the air flow disperser 13 and is connected to the synthesis reactor 09, the reaction tail gas pipeline 92 is provided with an air inlet 12, the other side opening is connected to the pure water control valve 14, the middle opening is connected to the anti-entrainment damper 15 and the liquid removal condenser 16 in sequence upward through a pipeline, the liquid removal condenser 16 is connected to the A-class gas-liquid mixing ejector 20 of the A-class absorption device 02 through a pipeline, and the lower side position of the absorption buffer tank 01 is connected to the dilute nitric acid transfer pump 17 , the dilute nitric acid transfer pump 17 is connected to the dilute nitric acid transfer tank 08 through the dilute nitric acid transfer valve 18. The lower part of the A-class absorption device 02 is an A-class absorption liquid tank 21, and an A-class absorption tower 22 is installed directly above the absorption liquid tank 21. A built-in heat exchanger 27 is arranged inside the A-class absorption liquid tank 21. A class A circulation pump 23 is arranged at the lower part of the outer side of the A-class absorption liquid tank 21. A tower spray head 25 is installed in the middle of the A-class absorption tower 22, and a high-position spray head 26 is installed on the upper part. A liquid removal net 28 is arranged on the top of the tower. A class A gas-liquid mixing ejector 20 is arranged on the outer side of the middle of the A-class absorption tower 22 and is connected to the tower spray head 25 forward. The side opening of the A-class gas-liquid mixing ejector 20 is connected to the reaction tail gas pipeline 92 from the synthesis reactor 09. The A-class circulation pump 23 is connected to the A-class gas-liquid mixing injector 20 and the high-position spray head 26 upward through pipelines, the A-class circulation pump 23 is connected to the dilute nitric acid transfer tank 08 through the A-class lifting valve 29, the top of the A-class absorption tower 22 is connected to the B-class gas-liquid mixing injector 33 of the B-class absorption device 03 through a pipeline, the structure of the B-class absorption device 03 is exactly the same as that of the A-class absorption device 02, the lower part of the B-class absorption device 03 is the B-class absorption liquid tank 30, the B-class absorption tower 31 is installed directly above the B-class absorption liquid tank 30, the B-class gas-liquid mixing injector 33 is arranged on one side of the middle of the B-class absorption tower 31, the B-class circulation pump 32 is arranged on the lower side of the B-class absorption liquid tank 30, and the B-class circulation pump 32 is connected to the A-class absorption liquid tank through the B-class lifting valve 34. 21, the top of the B-class absorption tower 31 is connected to the tower inlet inclined pipe 42 at the bottom of the C-class absorption tower 41 of the C-class absorption device 04 through a pipeline, the lower part of the C-class absorption device 04 is a C-class absorption liquid tank 40, and the C-class absorption tower 41 is installed directly above the C-class absorption liquid tank 40. The tower inlet inclined pipe 42 is arranged at the lower side of the C-class absorption tower 41, and the tower inlet inclined pipe 42 is connected to the top of the B-class absorption tower 31 through a pipeline, and the C-class circulation pump 43 is arranged at the lower side of the C-class absorption liquid tank 40. The C-class circulation pump 43 is connected to the upper part of the C-class absorption tower 41 through a pipeline, and the C-class circulation pump 43 is connected to the B-class absorption liquid tank 30 through a C-class lifting valve 44. The top of the C-class absorption tower 41 is connected to the D-class absorption tower 51 of the D-class absorption device 05 through a pipeline.The structure of the D-class absorption device 05 is exactly the same as that of the C-class absorption device 04. The lower part of the D-class absorption device 05 is a D-class absorption liquid tank 50. A D-class absorption tower 51 is installed directly above the D-class absorption liquid tank 50. A D-class circulation pump 52 is arranged on the lower side of the D-class absorption liquid tank 50 and is connected to the C-class absorption liquid tank 40 through a pipeline and a D-class lifting valve 53. The top of the D-class absorption tower 51 is connected to an induced draft fan 06. The induced draft fan 06 is connected to the bottom of the activated carbon purification box 07 through a pipeline. A harmless exhaust gas outlet 71 is arranged on the top of the activated carbon purification box 07. The above-mentioned absorption devices at various levels and various components are organically combined to form a combined device for absorbing and treating the exhaust gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention, which can effectively absorb and treat the nitrogen oxide exhaust gas of the glyoxylic acid synthesis reaction.

[0023] Furthermore, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of this specific implementation is characterized in that the anti-entrainment damper has a cylindrical or ellipsoidal appearance with conical protrusions at both ends, the main body diameter of the anti-entrainment damper is 2.5 to 3.0 times the diameter of the connected tail gas pipeline, the height is 80 to 100 cm, and the material is glass-lined or 904 stainless steel. The purpose of designing the anti-entrainment damper is to slow down and pre-absorb the high-speed airflow from the synthesis reactor to prevent the high-speed airflow from entraining the reaction materials and moving backward, thereby realizing the efficient absorption of nitrogen oxide tail gas by the A-D absorption device.

[0024] Furthermore, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation mode is characterized in that the air inlet is connected to an air purifier, and the air purifier is made of a PP tube with a length of 80 cm and a diameter of 100-125 mm, and 100-150 circular holes with an aperture of 10 mm are drilled on the surface of the PP tube, and the surface of the PP tube is covered with a single-layer filter cloth with an aperture of 100 mesh. The purpose of this design is to effectively prevent dust, flying debris and other impurities from entering the tail gas absorption system after the air is purified, thereby ensuring the quality of the dilute nitric acid obtained by the tail gas absorption.

[0025] Furthermore, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation mode is characterized in that the airflow disperser has an annular appearance and is welded and assembled from a hard PP pipe or PTFE pipe with a diameter of 40 to 50 mm, and its installation position is 50 to 60 cm away from the bottom of the absorption buffer tank. The purpose of this design is to ensure that the tail gas of nitrogen oxides can be evenly dispersed into the absorption liquid in the absorption buffer tank to achieve the purpose of efficient absorption.

[0026] Furthermore, the combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation is characterized in that 150 to 200 circular holes with a diameter of 5.0 to 10 mm are opened on the downward half surface of the airflow disperser. The purpose of opening circular holes on the downward half surface is also to achieve efficient absorption of nitrogen oxide tail gas.

[0027] Furthermore, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation mode is characterized in that the built-in heat exchanger is welded by a PP pipe with a diameter of 15 to 20 mm, and the heat exchange area is 40 to 50 m 2 The purpose of designing and installing a built-in heat exchanger for cooling is to reduce the large amount of heat generated by the forced absorption of exhaust gas by the gas-liquid mixing ejector, so as to ensure process safety and improve production efficiency.

[0028] Furthermore, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation mode is characterized in that the inlet inclined pipe is at an angle of 30 to 60 degrees with the absorption tower, and the inlet inclined pipe extends 5.0 to 10 cm into the absorption tower. The purpose of this design is to prevent the spray liquid from entering the tail gas pipeline and causing local blockage or poor air flow.

[0029] Furthermore, the combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation mode is characterized in that the liquid removal net is composed of 6 to 8 layers of acid-resistant stainless steel wire mesh, and the mass transfer area is 40 to 50 m 2 The purpose of this design is to ensure that the high-speed airflow does not carry the liquid material out of the absorption device, thereby ensuring that the nitrogen oxide tail gas is effectively absorbed inside the absorption tower.

[0030] Furthermore, a combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the embodiment of the present specific implementation method can be described in a simple process operation flow as follows: the tail gas of the glyoxylic acid synthesis reaction from the synthesis reactor 09 enters the absorption buffer tank 01 pre-added with 1 / 2 amount of water through the reaction reflux condenser 91 and the reaction tail gas pipeline 92, and then disperses the small bubbles through the air flow disperser 13 to be partially absorbed by the water. The reaction tail gas preliminarily absorbed goes along the tail gas pipeline through the anti-entrainment damper 15 and the liquid removal condenser 16 to the A-class absorption device 02, and is forcibly absorbed by the negative pressure generated by the high-speed jet flow generated by the gas-liquid mixing ejector 24 and is forcibly brought into the A-class absorption tower 22. The air flow is from bottom to top, and the absorption liquid is from top to bottom, and the water absorption reaction of nitrogen oxides is completed in the absorption tower; the tail gas coming out of the A-class absorption tower 22 is then passed through the B-class absorption device 03, the C-class absorption device 04, and the D-class absorption device 05. Efficient absorption, and finally discharged from the harmless tail gas outlet 71 after purification by the induced draft fan 06 and the activated carbon purification box 07; when it is detected that the absorption liquid concentration in the absorption buffer tank 01 reaches the technical index of dilute nitric acid, the dilute nitric acid transfer pump 17 is started to transfer a certain concentration of dilute nitric acid to the dilute nitric acid transfer tank 08; when it is detected that the absorption liquid concentration in the Class A absorption liquid tank 21 reaches the technical index of dilute nitric acid, the Class A circulation pump 23 is started to transfer the dilute nitric acid to the dilute nitric acid transfer tank 08, and then, the Class B circulation pump 32 is started again, and the absorption liquid in the Class B absorption liquid tank 30 is transferred to the Class A absorption liquid tank 21 by similar operation; next, the Class C circulation pump 43 is started to transfer the absorption liquid in the Class C absorption liquid tank 40 to the Class B absorption liquid tank 30, and then, the Class D transfer pump 52 is started to transfer the absorption liquid in the Class D absorption liquid tank 50 to the Class C absorption liquid tank 40, and then new pure water is added to the Class D absorption liquid tank 50. In this way, the tail gas of the glyoxylic acid synthesis reaction moves step by step from the absorption buffer tank 01 to the D-level absorption device 05, and the concentration of nitrogen oxides gradually decreases, while the absorption liquid whose effective ingredient is dilute nitric acid moves step by step from the D-level absorption device 05 to the dilute nitric acid transfer tank 08, so that the effective concentration of the dilute nitric acid gradually reaches the requirements of the technical indicators.

[0031] The combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention has obvious beneficial effects in the following aspects: (1) adding an air inlet to the front tail gas pipeline can effectively enhance the conversion of nitrogen monoxide to nitrogen dioxide, which is beneficial to accelerating absorption, and installing an air purifier is beneficial to avoiding the introduction of impurities; (2) the design and installation of the absorption buffer tank can effectively reduce the speed of the high-speed tail gas flow for pre-absorption, which is very beneficial to the absorption of nitrogen oxides; 3. The design and installation of a gas-liquid mixing ejector can force the absorption of nitrogen oxides, which is very beneficial to the improvement of absorption effect and production efficiency; 4. The design and installation of a built-in heat exchanger in the absorption liquid tank can effectively cool down the absorption liquid that is rapidly heated after forced absorption by the gas-liquid mixing ejector, which is beneficial to process safety and improving production efficiency; 5. The step-by-step forward movement of the absorption liquid at the end can effectively ensure that a small amount of dilute nitric acid and pure water will not be wasted, which is very beneficial to the effective use of water resources and the reduction of energy consumption.

[0032] Such a device, a combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction as described in the technical solution of the present invention, effectively solves the problems of low absorption efficiency and incomplete absorption of nitrogen oxide absorption devices in the past, and solves the problem of low nitric acid content in the absorption liquid, which is more beneficial to environmental protection and production cost control.

[0033] Such a device, a combined device for absorbing and treating the tail gas of the glyoxylic acid synthesis reaction described in the technical solution of the present invention, also has the characteristics of safe process, convenient operation and high production efficiency.

[0034] Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The protection scope of the present invention is to conform to the widest scope consistent with the principles and novel features described herein.

Claims

1. A combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction, comprising: Absorption buffer tank, air inlet, air purifier, air flow disperser, pure water control valve, anti-entrainment damper, liquid removal condenser, Class A absorption device, Class A absorption tower, Class A absorption liquid tank, Class A gas-liquid mixing ejector, Class A spray control valve, tower spray head, high-position spray head, liquid removal net, Class A circulation pump, Class A lifting valve, Class B absorption device, Class B absorption tower, Class B absorption liquid tank, Class B circulation pump, Class B gas-liquid mixer, Class B spray control valve, Class B lifting valve, Class C absorption device, Class C absorption tower, Class C absorption liquid tank, tower inlet inclined pipe, Class C circulation pump, Class C lifting valve, Class D absorption device, Class D absorption tower, Class D absorption liquid tank, Class D circulation pump, Class D lifting valve, induced draft fan, activated carbon purification box, harmless tail gas outlet, dilute nitric acid The invention relates to a transfer tank, a synthesis reactor, a reaction reflux condenser and a reaction tail gas pipeline, wherein an air flow disperser is arranged inside the absorption buffer tank, three openings are arranged on the upper part of the absorption buffer tank, one opening is connected to the reaction tail gas pipeline and the synthesis reactor through the air flow disperser, an air inlet is arranged on the reaction tail gas pipeline, the other opening is connected to the pure water control valve, the middle opening is connected to the anti-entrainment damper and the liquid removal condenser in sequence upward through a pipeline, the liquid removal condenser is connected to the A-class gas-liquid mixing ejector of the A-class absorption device forward through a pipeline, a dilute nitric acid transfer pump is connected to the lower side of the absorption buffer tank, the dilute nitric acid transfer pump is connected to the dilute nitric acid transfer tank through a dilute nitric acid transfer valve, and the lower part of the A-class absorption device is an A-class absorption liquid tank, A Class A absorption tower is installed directly above the absorption liquid tank. A built-in heat exchanger is arranged inside the Class A absorption liquid tank. A Class A circulation pump is arranged at the lower outer part of the Class A absorption liquid tank. A tower spray head is added in the middle of the Class A absorption tower, a high-position spray head is added in the upper part, and a liquid removal net is arranged on the top of the tower. A Class A gas-liquid mixing ejector is arranged outside the middle of the Class A absorption tower and is connected forward to the tower spray head. The side opening of the Class A gas-liquid mixing ejector is connected to the reaction tail gas pipeline from the synthesis reactor. The Class A circulation pump is connected to the Class A gas-liquid mixing ejector and the high-position spray head upward through pipelines, respectively. The Class A circulation pump is connected to the dilute nitric acid transfer tank through an A-class lifting valve. The top of the Class A absorption tower is connected to the Class B gas-liquid mixing ejector of the Class B absorption device through a pipeline. The device has the same structure as the A-class absorption device. The lower part of the B-class absorption device is a B-class absorption liquid tank. A B-class absorption tower is installed directly above the B-class absorption liquid tank. A B-class gas-liquid mixing ejector is arranged on one side of the middle of the B-class absorption tower. A B-class circulation pump is arranged on the lower side of the B-class absorption liquid tank. The B-class circulation pump is connected to the A-class absorption liquid tank through a B-class lifting valve. The top of the B-class absorption tower is connected to the tower inlet inclined pipe at the bottom of the C-class absorption tower of the C-class absorption device through a pipeline. The lower part of the C-class absorption device is a C-class absorption liquid tank. A C-class absorption tower is installed directly above the C-class absorption liquid tank. An inlet tower inclined pipe is arranged on the lower side of the C-class absorption tower. The inlet tower inclined pipe is connected to the top of the B-class absorption tower through a pipeline. A C-class circulation pump is arranged on the lower side of the C-class absorption liquid tank.The C-class circulation pump is connected to the upper part of the C-class absorption tower through a pipeline, and the C-class circulation pump is connected to the B-class absorption liquid tank through a C-class lifting valve. The top of the C-class absorption tower is connected to the D-class absorption tower of the D-class absorption device through a pipeline. The D-class absorption device has the same structure as the C-class absorption device. The lower part of the D-class absorption device is the D-class absorption liquid tank. The D-class absorption tower is installed directly above the D-class absorption liquid tank. The D-class circulation pump is set on the side of the lower part of the D-class absorption liquid tank and is connected to the C-class absorption liquid tank through a pipeline and a D-class lifting valve. The top of the D-class absorption tower is connected to the induced draft fan, which is connected to the bottom of the activated carbon purification box through a pipeline. The top of the activated carbon purification box is provided with a harmless exhaust gas outlet. , 2. The combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to claim 1, characterized in that: The anti-entrainment damper has the appearance of a cylinder or ellipsoid with conical protrusions at both ends. The main body diameter of the anti-entrainment damper is 2.5 to 3.0 times the diameter of the connected exhaust pipe, the height is 80 to 100 cm, and the material is glass-lined or 904 stainless steel.

3. The combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to claim 1, characterized in that: The air inlet is connected to an air purifier, which is made of a PP tube with a length of 80 cm and a diameter of 100-125 mm. 100-150 circular holes with an aperture of 10 mm are drilled on the surface of the PP tube, and a single-layer filter cloth with an aperture of 100 mesh is wrapped on the surface of the PP tube.

4. The combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to claim 1, characterized in that: The air flow disperser has a ring-shaped appearance and is formed by welding a hard PP pipe or PTFE pipe with a diameter of 40 to 50 mm. Its installation position is 50 to 60 cm away from the bottom of the absorption buffer tank.

5. The combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to claim 1, characterized in that: The downward half surface of the air flow disperser is provided with 150 to 200 circular holes with a diameter of 5.0 to 10 mm.

6. The combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to claim 1, characterized in that: The internal heat exchanger is welded from PP pipes with a diameter of 15 to 20 mm, and the heat exchange area is 40 to 50 m 2 .

7. The combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to claim 1, characterized in that: The tower inlet inclined pipe is at an angle of 30 to 60 degrees to the absorption tower, and the tower inlet inclined pipe extends 5.0 to 10 cm into the absorption tower.

8. The combined device for absorbing and treating tail gas from a glyoxylic acid synthesis reaction according to claim 1, characterized in that: The liquid removal net is composed of 6 to 8 layers of acid-resistant stainless steel wire mesh, with a mass transfer area of ​​40 to 50 m 2 .

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