A device for safely processing alcohol tail gas by-produced in phosphite antioxidant production

Abstract

The utility model belongs to tail gas treatment technical field especially, it is a kind of phosphite antioxidant byproduct alcohol tail gas safe treatment device, for the problem that traditional water spraying method handles alcohol tail gas and is easy to reduce efficiency due to absorption saturation and large sewage volume, and catalytic combustion method directly handles high concentration tail gas and has open fire hidden danger, present and propose following scheme, including primary spray tower and secondary spray tower, catalytic combustion device is equipped between primary spray tower and secondary spray tower, and the bottom of both is connected with water collecting tank;Primary spray tower water collecting tank connects waste water purification assembly, and heat transfer oil heat exchanger is equipped between catalytic combustion device and secondary spray tower, in the utility model, the combination arrangement of fire arrester and two-stage spray tower effectively prevents open fire backtracking, and improves safety;Steam stripping column and aeration tank are used to purify spray waste water and recycle, reduce sewage discharge;And the heat generated by catalytic combustion is recovered by heat transfer oil heat exchanger to provide heat for stripping column, reduce system energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of exhaust gas treatment technology, and in particular to a safety treatment device for alcohols produced as a byproduct of phosphite antioxidants. Background Technology

[0002] During the production of phosphite antioxidants, byproduct alcohols containing methanol, ethanol, and other components are generated. If these byproducts are emitted directly, they can easily cause the concentration of air pollutants to exceed the standards and fail to meet environmental protection requirements. Therefore, they need to be purified by a special treatment device.

[0003] Currently, the commonly used exhaust gas treatment methods in the industry mainly include water spray absorption and catalytic combustion. Both methods have their applications in alcohol exhaust gas treatment, but each has certain limitations when used alone: ​​In the existing water spray absorption method for treating alcohol exhaust gas, the spray water easily becomes saturated due to the absorption of alcohols, leading to a significant decrease in absorption efficiency. To ensure treatment effectiveness, the spray water needs to be frequently replaced, which generates a large amount of wastewater, increasing subsequent wastewater treatment costs and environmental pressure. In the existing catalytic combustion method for treating alcohol exhaust gas, if the exhaust gas is directly introduced into the catalytic combustion device, the high concentration of alcohols in the exhaust gas can easily generate open flames during combustion, posing a safety hazard of open flames entering the production system. Therefore, we propose a safe treatment device for alcohol exhaust gas produced as a byproduct of phosphite antioxidants to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies, such as the efficiency reduction and large wastewater volume caused by the traditional water spraying method for treating alcohol tail gas due to absorption saturation, and the safety hazard of open flame in the direct treatment of high-concentration tail gas by catalytic combustion method. Therefore, this invention proposes a safe treatment device for alcohol tail gas produced as a byproduct of phosphite antioxidants.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A safety treatment device for alcohol by-product tail gas from phosphite antioxidants includes a primary spray tower and a secondary spray tower. A catalytic combustion device is installed between the primary and secondary spray towers. The inlet of the catalytic combustion device is connected to the exhaust port of the primary spray tower, and the outlet of the catalytic combustion device is connected to the inlet of the secondary spray tower. An activated carbon box is connected to the outlet of the secondary spray tower, and activated carbon is installed inside the activated carbon box.

[0007] The bottom of both the primary and secondary spray towers is connected to a water collection tank. The outlet of the water collection tank at the bottom of the primary spray tower is connected to a wastewater purification component, which includes a steam stripping tower and an aeration tank. The steam stripping tower and the aeration tank are respectively located near the primary spray tower. The inlet of the steam stripping tower is connected to the outlet of the water collection tank at the bottom of the primary spray tower through pipe I. The outlet of the steam stripping tower and the outlet of the water collection tank at the bottom of the secondary spray tower are respectively connected to the interior of the aeration tank through pipe II.

[0008] A heat recovery component is provided between the secondary spray tower and the catalytic combustion device. The heat recovery component includes a heat transfer oil heat exchanger. The air inlet of the heat transfer oil heat exchanger is connected to the air outlet of the catalytic combustion device, and the air outlet of the heat transfer oil heat exchanger is connected to the air inlet of the secondary spray tower.

[0009] The air inlet of the primary spray tower is fixedly connected to a flame arrester.

[0010] In one possible design, the wastewater purification assembly further includes a collection tank, which is fixedly installed on one side of the steam stripping tower, and the inlet of the collection tank is connected to the exhaust port of the steam stripping tower.

[0011] In one possible design, the pipeline I is equipped with a water pump I for transporting wastewater to the steam stripping tower, and both pipelines II are equipped with water pumps II for transporting wastewater to the aeration tank.

[0012] In one possible design, the oil outlet of the heat transfer oil heat exchanger is connected to the liquid inlet of the evaporator inside the steam stripping tower via an oil outlet pipe, and the oil return port of the heat transfer oil heat exchanger is connected to the liquid outlet of the evaporator inside the steam stripping tower via a return oil pipe, with an oil pump fixedly installed on the return oil pipe.

[0013] In one possible design, a demister is provided between the secondary spray tower and the activated carbon box, with the air outlet of the secondary spray tower connected to the air inlet of the demister, and the air inlet of the activated carbon box connected to the air outlet of the demister.

[0014] In one possible design, both sides of the aeration tank are fixedly connected to connecting pipes, and the two connecting pipes are respectively connected to the spraying mechanism in the primary spray tower and the secondary spray tower, and a water pump III is installed on both connecting pipes.

[0015] In one possible design, two filter boxes are symmetrically fixedly installed inside the aeration tank, and the inlet ends of the two connecting pipes extend into the interior of the corresponding filter boxes.

[0016] In this application, firstly, the alcohol-containing tail gas enters the first-stage spray tower through the flame arrester at the inlet of the first-stage spray tower. The flame arrester can prevent open flames generated in subsequent stages from entering the production system and improve safety. The spraying mechanism in the first-stage spray tower sprays spray water to initially absorb the alcohol substances in the tail gas, stabilize the tail gas concentration, and prevent high-concentration tail gas from directly entering the catalytic combustion device and generating open flames.

[0017] The treated exhaust gas enters the catalytic combustion device from the exhaust port of the first-stage spray tower for combustion treatment, further decomposing the alcohols in the exhaust gas and improving the purification effect; the high-temperature flue gas generated by the catalytic combustion device enters the heat transfer oil heat exchanger from its outlet, exchanges heat with the heat transfer oil in the heat transfer oil heat exchanger, recovers the heat in the flue gas, provides heat energy for the evaporator inside the subsequent steam stripping tower, and reduces energy consumption.

[0018] After heat exchange, the flue gas enters the secondary spray tower from the outlet of the heat transfer oil heat exchanger. The spray mechanism in the secondary spray tower sprays spray water to absorb the residual alcohols in the flue gas again, further improving the exhaust gas purification effect, while blocking any possible open flames.

[0019] After being treated by the secondary spray tower, the gas enters the demister to remove moisture and impurities, preventing water vapor and impurities from affecting the adsorption effect of activated carbon, and at the same time preventing open flames from entering the activated carbon box. The defoamed gas enters the activated carbon box and is further adsorbed and purified by the activated carbon to ensure that the exhaust gas meets the emission standards, and is finally discharged from the exhaust end of the activated carbon box.

[0020] Meanwhile, the saturated wastewater collected in the collection tank at the bottom of the primary spray tower is transported to the steam stripping tower via pipe I and pump I to separate alcohols from the wastewater, achieving preliminary wastewater treatment. The heated heat transfer oil in the heat transfer oil heat exchanger is then transported to the evaporator inside the steam stripping tower via the oil outlet pipe, providing heat to the evaporator without requiring additional energy, thus reducing energy consumption. The heat transfer oil after heat exchange flows back to the heat transfer oil heat exchanger via the return oil pipe and oil pump to continue absorbing heat from the high-temperature flue gas, forming a cycle. The wastewater treated by the steam stripping tower is transported to the aeration tank via pipe II and pump II. The wastewater collected in the collection tank at the bottom of the secondary spray tower is also transported to the aeration tank via pipe II and pump II for biochemical degradation, achieving deep purification of the wastewater and meeting the requirements for recycling.

[0021] The filtered wastewater is returned to the spraying mechanism of the primary and secondary spray towers through the connecting pipe and water pump III, realizing the recycling of spray water and reducing sewage discharge. The filter box prevents impurities in the aeration tank from entering the primary and secondary spray towers.

[0022] Beneficial effects: In this utility model, the safe treatment device for alcohol by-product tail gas of phosphite antioxidant is provided by setting a catalytic combustion device between a primary spray tower and a secondary spray tower equipped with a flame arrester. The primary spray tower can preliminarily absorb the incoming alcohol-containing tail gas to stabilize the tail gas concentration and prevent high-concentration tail gas from directly entering the catalytic combustion device and generating an open flame. The flame arrester can prevent the open flame from entering the production system. The secondary spray tower can reabsorb the alcohol-containing tail gas remaining after catalytic combustion. In conjunction with the demister, it can prevent the open flame from entering the activated carbon box, thereby achieving the purpose of improving the safety and purification effect of tail gas treatment.

[0023] In this utility model, the safe treatment device for alcohol by-product tail gas of phosphite antioxidant connects the water collection tank at the bottom of the primary spray tower with a steam stripping tower and an aeration tank. The steam stripping tower can strip the saturated wastewater generated by the primary spray tower to separate the alcohol substances. The aeration tank can further purify the wastewater treated by the steam stripping tower and the wastewater from the secondary spray tower. The purified wastewater can also be returned to the spraying mechanism of the two-stage spray tower through the connecting pipe and water pump III, thereby reducing the frequency of spray water replacement, reducing the amount of sewage discharged, and realizing the purpose of spray water recycling.

[0024] In this utility model, the safety treatment device for alcohol by-product tail gas of phosphite antioxidant is provided by setting a heat transfer oil heat exchanger between the secondary spray tower and the catalytic combustion device. The heat transfer oil heat exchanger is connected to the evaporator inside the steam stripping tower through an oil outlet pipe and an oil return pipe. The high-temperature flue gas generated by the catalytic combustion device can heat the heat transfer oil through the heat transfer oil heat exchanger. The heated heat transfer oil can provide heat to the evaporator of the steam stripping tower without the need for additional energy consumption to heat the steam stripping tower, thereby achieving the purpose of recovering and utilizing the heat of catalytic combustion and reducing the overall energy consumption of the device.

[0025] In this invention, by setting up a catalytic combustion device between the primary and secondary spray towers, and equipping it with a flame arrester and a demister, the safety and purification effect of the exhaust gas treatment are effectively improved; the steam stripping tower and aeration tank purify the wastewater and recycle it, significantly reducing sewage discharge and spray water consumption; at the same time, the heat energy generated by catalytic combustion is recovered by using a heat transfer oil heat exchanger to heat the steam stripping tower, reducing the overall energy consumption of the device. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural schematic diagram of a safety treatment device for alcohol by-product tail gas of phosphite antioxidant proposed in this utility model.

[0027] Figure 2 This is a schematic diagram of another perspective of the safety treatment device for alcohol by-product tail gas of phosphite antioxidant proposed in this utility model.

[0028] Figure 3This is a partial three-dimensional structural schematic diagram of a safety treatment device for alcohol by-products of phosphite antioxidants proposed in this utility model.

[0029] In the diagram: 1. Primary spray tower; 2. Secondary spray tower; 3. Catalytic combustion device; 4. Demister; 5. Activated carbon box; 6. Water collection tank; 7. Steam stripping tower; 8. Collection tank; 9. Aeration tank; 10. Water pump I; 11. Water pump II; 12. Thermal oil heat exchanger; 13. Oil pump; 14. Flame arrester; 15. Water pump III; 16. Connecting pipe; 17. Filter box. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0031] In one embodiment: Refer to Figure 1-3 A tail gas safety treatment device includes a primary spray tower 1, a secondary spray tower 2, a catalytic combustion device 3, a demister 4, an activated carbon box 5, a water collection tank 6, a steam stripping tower 7, a collection tank 8, an aeration tank 9, a water pump I 10, a water pump II 11, a heat transfer oil heat exchanger 12, an oil pump 13, a flame arrester 14, a water pump III 15, a connecting pipe 16, and a filter box 17. The components are connected by pipelines according to functional requirements to form a complete tail gas treatment and resource recovery system.

[0032] The air inlet of the primary spray tower 1 is fixedly connected to a flame arrester 14. The flame arrester 14, through its internally filled flame-arresting core material, prevents flames or sparks from propagating through its internal channels, thus preventing open flames from subsequent processes from entering the production system and improving the overall safety of the device. The primary spray tower 1 is equipped with a spraying mechanism that atomizes and evenly sprays water, ensuring sufficient contact between the spray water and the alcohol-containing exhaust gas entering the tower. Utilizing the water-soluble properties of alcohols, this mechanism achieves preliminary absorption of alcohols in the exhaust gas. This process stabilizes the alcohol concentration in the exhaust gas, preventing high-concentration exhaust gas from directly entering subsequent components and causing safety issues. The bottom of the primary spray tower 1 is connected to a water collection tank 6, where the saturated spray wastewater formed after the preliminary absorption of the exhaust gas is temporarily stored.

[0033] The exhaust port of the primary spray tower 1 is connected to the air inlet of the catalytic combustion device 3. The exhaust gas after preliminary treatment by the primary spray tower 1 enters the catalytic combustion device 3. The catalytic combustion device 3 is equipped with a special catalyst. Under the catalytic action of the catalyst, the alcohols in the exhaust gas can react with oxygen at a lower temperature to produce harmless carbon dioxide and water. This process further reduces the alcohol content in the exhaust gas and improves the exhaust gas purification effect. At the same time, the reaction process releases heat to form high-temperature flue gas.

[0034] The outlet of the catalytic combustion device 3 is connected to the inlet of the heat transfer oil heat exchanger 12, allowing the high-temperature flue gas generated by catalytic combustion to enter the heat transfer oil heat exchanger 12. The heat transfer oil heat exchanger 12 is filled with heat transfer oil, which has good thermal stability and thermal conductivity. The high-temperature flue gas and the heat transfer oil transfer heat through the heat exchange tube bundle within the heat exchanger, thus recovering the heat from combustion.

[0035] The oil outlet of the heat transfer oil heat exchanger 12 is connected to the liquid inlet of the evaporator inside the steam stripping tower 7 via an oil outlet pipe. The oil return port of the heat transfer oil heat exchanger 12 is connected to the liquid outlet of the evaporator inside the steam stripping tower 7 via a return oil pipe. An oil pump 13 is fixedly installed on the return oil pipe. The heat transfer oil, heated by the high-temperature flue gas, enters the evaporator of the steam stripping tower 7 through the oil outlet pipe under the drive of the oil pump 13. The evaporator uses the heat transferred by the heat transfer oil to heat the wastewater in the tower, meeting the thermal energy requirements of the steam stripping tower 7 during operation, without the need for additional external energy consumption, thus reducing the overall energy consumption of the unit. The heat transfer oil that has completed heat exchange flows back to the heat transfer oil heat exchanger 12 through the return oil pipe to continue absorbing heat from the high-temperature flue gas, forming a heat transfer oil circulation.

[0036] The outlet of the heat transfer oil heat exchanger 12 is connected to the inlet of the secondary spray tower 2. The flue gas, cooled by the heat transfer oil heat exchanger 12, enters the secondary spray tower 2. The secondary spray tower 2 also has a spraying mechanism, which operates on the same principle as the primary spray tower 1. It uses atomized spray water to fully contact the flue gas, utilizing the water solubility of alcohols to reabsorb residual alcohols in the flue gas, further improving the purification effect of the exhaust gas. Simultaneously, the spray water also acts as a physical barrier, preventing potential open flames from affecting subsequent components. The bottom of the secondary spray tower 2 is also connected to a water collection tank 6, where wastewater generated after absorbing residual alcohols is temporarily stored.

[0037] The outlet of the secondary spray tower 2 is connected to the inlet of the demister 4. The gas treated by the secondary spray tower 2 enters the interior of the demister 4. The demister 4 uses internal baffles or wire mesh components to change the direction of the gas containing mist droplets during the flow process, and uses inertial force to separate the mist droplets. At the same time, it intercepts solid impurities carried in the gas, preventing moisture and impurities from affecting the subsequent adsorption effect, and also preventing open flames from entering the subsequent components through the gas.

[0038] The outlet of the demister 4 is connected to the inlet of the activated carbon box 5. The activated carbon box 5 is filled with activated carbon, which has a rich pore structure and a large specific surface area. When the gas that has been demisted enters the activated carbon box 5, the trace pollutants in the gas will be adsorbed and trapped by the pores of the activated carbon. Through this physical adsorption process, it is ensured that the gas discharged in the end meets the environmental protection requirements.

[0039] The outlet of the water collection tank 6 located at the bottom of the primary spray tower 1 is connected to the inlet of the steam stripping tower 7 via pipe I. A water pump I10 is installed on pipe I. The water pump I10 uses the centrifugal force generated by the rotation of its impeller to transport the temporarily stored saturated spray wastewater in the water collection tank 6 into the steam stripping tower 7. The steam stripping tower 7 utilizes the boiling point difference between alcohols and water. An evaporator heats the wastewater, causing the alcohols to evaporate and form steam. This steam then passes through the packing layer inside the tower and comes into counter-current contact with the descending wastewater, achieving the separation of alcohols and water and completing the initial purification of the wastewater.

[0040] A collection tank 8 is fixedly installed on one side of the steam stripping tower 7. The inlet of the collection tank 8 is connected to the exhaust port of the steam stripping tower 7. The alcohol-containing vapors volatilized during the operation of the steam stripping tower 7 can enter the collection tank 8 and be condensed by cooling or pressurization, which facilitates the subsequent recovery and utilization of alcohols.

[0041] This application can be used in the field of exhaust gas treatment technology, or in other fields applicable to this application.

[0042] In another embodiment: Reference Figure 2-3 An improvement upon Example 1: A safe treatment device for alcohol byproduct tail gas from phosphite antioxidants, applied in the field of tail gas treatment technology. The outlet of the steam stripping tower 7 is connected to the interior of the aeration tank 9 via pipe II. The outlet of the water collection tank 6 at the bottom of the secondary spray tower 2 is also connected to the interior of the aeration tank 9 via pipe II. Water pumps II11 are installed on both pipes II. The working principle of water pumps II11 is the same as that of water pump I10. Through power, the wastewater initially purified by the steam stripping tower 7 and the wastewater in the water collection tank 6 at the bottom of the secondary spray tower 2 are transported to the interior of the aeration tank 9. Microbial communities are cultivated inside the aeration tank 9. By introducing air into the tank, oxygen is provided to the microorganisms. The microorganisms utilize the organic matter in the wastewater as nutrients for metabolic activities, decomposing the organic matter into harmless inorganic substances, achieving deep purification of the wastewater and enabling it to meet the standards for recycling.

[0043] Two filter boxes 17 are symmetrically fixed inside the aeration tank 9. The filter boxes 17 are filled with filter media to filter the deeply purified wastewater in the aeration tank 9, intercepting any residual microbial flocs or solid impurities in the water, preventing impurities from entering the spray mechanism and causing blockage, thus affecting the spraying effect. Connecting pipes 16 are fixed on both sides of the aeration tank 9. The inlet ends of the two connecting pipes 16 extend into the corresponding filter boxes 17, and the outlet ends of the two connecting pipes 16 are connected to the spray mechanisms in the primary spray tower 1 and the secondary spray tower 2, respectively. A water pump Ⅲ 15 is installed on the connecting pipe 16. The water pump Ⅲ 15 transports the filtered wastewater through the connecting pipe 16 to the spray mechanisms of the primary spray tower 1 and the secondary spray tower 2, realizing the recycling of spray water, reducing the frequency of spray water replacement, and lowering the amount of wastewater discharged.

[0044] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0045] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A safety treatment device for alcohol by-product tail gas from phosphite antioxidants, comprising a primary spray tower (1) and a secondary spray tower (2), characterized in that, A catalytic combustion device (3) is provided between the primary spray tower (1) and the secondary spray tower (2). The air inlet of the catalytic combustion device (3) is connected to the exhaust port of the primary spray tower (1), and the air outlet of the catalytic combustion device (3) is connected to the air inlet of the secondary spray tower (2). The air outlet of the secondary spray tower (2) is connected to an activated carbon box (5), and activated carbon is provided inside the activated carbon box (5). The bottom of both the primary spray tower (1) and the secondary spray tower (2) is connected to a water collection tank (6). The outlet of the water collection tank (6) at the bottom of the primary spray tower (1) is connected to a wastewater purification component. The wastewater purification component includes a steam stripping tower (7) and an aeration tank (9). The steam stripping tower (7) and the aeration tank (9) are respectively located near the primary spray tower (1). The inlet of the steam stripping tower (7) is connected to the outlet of the water collection tank (6) at the bottom of the primary spray tower (1) through pipe I. The outlet of the steam stripping tower (7) and the outlet of the water collection tank (6) at the bottom of the secondary spray tower (2) are respectively connected to the interior of the aeration tank (9) through pipe II. A heat recovery component is provided between the secondary spray tower (2) and the catalytic combustion device (3). The heat recovery component includes a heat transfer oil heat exchanger (12). The air inlet of the heat transfer oil heat exchanger (12) is connected to the air outlet of the catalytic combustion device (3), and the air outlet of the heat transfer oil heat exchanger (12) is connected to the air inlet of the secondary spray tower (2). The air inlet of the primary spray tower (1) is fixedly connected to a flame arrester (14).

2. The device for safe treatment of alcohol by-product tail gas from phosphite antioxidants according to claim 1, characterized in that, The wastewater purification assembly also includes a collection tank (8), which is fixedly installed on one side of the steam stripping tower (7), and the inlet of the collection tank (8) is connected to the exhaust port of the steam stripping tower (7).

3. The device for safe treatment of alcohol by-product tail gas from phosphite antioxidants according to claim 1, characterized in that, The pipeline I is equipped with a water pump I (10) for transporting wastewater to the steam stripping tower (7), and both pipelines II are equipped with water pumps II (11) for transporting wastewater to the aeration tank (9).

4. The device for safe treatment of alcohol by-product tail gas from phosphite antioxidants according to claim 1, characterized in that, The oil outlet of the heat transfer oil heat exchanger (12) is connected to the liquid inlet of the evaporator inside the steam stripping tower (7) through the oil outlet pipe. The oil return port of the heat transfer oil heat exchanger (12) is connected to the liquid outlet of the evaporator inside the steam stripping tower (7) through the oil return pipe. An oil pump (13) is fixedly installed on the oil return pipe.

5. The device for safe treatment of alcohol by-product tail gas from phosphite antioxidants according to claim 1, characterized in that, A demister (4) is provided between the secondary spray tower (2) and the activated carbon box (5). The air outlet of the secondary spray tower (2) is connected to the air inlet of the demister (4), and the air inlet of the activated carbon box (5) is connected to the air outlet of the demister (4).

6. The device for safe treatment of alcohol by-product tail gas from phosphite antioxidants according to claim 1, characterized in that, Both sides of the aeration tank (9) are fixedly connected to connecting pipes (16). The two connecting pipes (16) are respectively connected to the spraying mechanism in the first-stage spray tower (1) and the second-stage spray tower (2). Water pump III (15) is installed on both connecting pipes (16).

7. The device for safe treatment of alcohol by-product tail gas from phosphite antioxidants according to claim 6, characterized in that, The aeration tank (9) is symmetrically and fixedly equipped with two filter boxes (17), and the inlet ends of the two connecting pipes (16) extend into the interior of the corresponding filter boxes (17).

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