A system for treating organic amine carbon capture wastewater from a power plant

Abstract

The application discloses a kind of for power plant organic amine carbon capture wastewater treatment system, the outlet of No. 1 water collecting pool is connected with the inlet of resin adsorption tower by security filter, the outlet of resin adsorption tower is divided into two ways, one of which is connected with the inlet of homogeneous conditioning pool, the other is connected with the inlet of biological reactor;The outlet of No. 2 water collecting pool is connected with the inlet of coagulation sedimentation tank, the outlet of coagulation sedimentation tank is connected with the inlet of homogeneous conditioning pool, the outlet of homogeneous conditioning pool is connected with the inlet of wet catalytic oxidation device, the outlet of wet catalytic oxidation device is connected with the inlet of biological reactor, the outlet of biological reactor is connected with power plant zero emission system, the system can treat pollutants in organic amine carbon capture wastewater, and has the characteristics of large processing capacity and not easy to cause pollution.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wastewater treatment, and relates to a wastewater treatment system for organic amine carbon capture in a power plant. BACKGROUND

[0002] A thermal power plant is one of important sources of CO2 emission. In order to control the emission of CO2, the power plant usually makes flue gas pass through a specially designed absorption device after combustion to separate CO2 from the mixed gas for emission, so as to reduce the emission of CO2. Among numerous carbon capture technologies, the organic amine chemical absorption method is a simple process and a relatively mature emerging capture technology for post-combustion CO2 capture, and is most widely applied in power plants.

[0003] However, after the organic amine chemical absorption method for capturing CO2 is used for multiple cycles in the production process, the absorption liquid deteriorates, the absorption efficiency decreases, and the solution purification wastewater is generated, which contains organic amines, amine derivatives (methanol amine salt formed by formate, acetate and oxalate) and a certain amount of inorganic salts (sulfate, sulfite, nitrate, nitrite, etc.). In addition, after the organic amine chemical absorbent is used for capturing carbon dioxide, a small amount of absorbent is left in the absorption device and the storage tank containing the absorbent, and a certain amount of equipment cleaning wastewater is generated by flushing with middle water or tap water. This kind of wastewater is a certain concentration of organic amine solution with low salt content.

[0004] The incineration method is a common method for treating such carbon capture wastewater, but the method is low in efficiency, it is difficult to treat a large amount of wastewater and is easy to cause pollution. Therefore, under the background of zero emission of wastewater in power plants, it is necessary to develop a high-efficiency carbon capture wastewater treatment system to treat the pollutants in the wastewater and ensure the normal operation of the zero emission system of the power plant. SUMMARY

[0005] The application aims to overcome the shortcomings of the prior art, and provides a wastewater treatment system for organic amine carbon capture in a power plant, which can treat the pollutants in the wastewater and has the characteristics of large treatment capacity and difficulty in causing pollution.

[0006] To achieve the above-mentioned purpose, the application discloses a wastewater treatment system for organic amine carbon capture in a power plant, which comprises a first water collecting pool, a security filter, a resin adsorption tower, a second water collecting pool, a coagulation sedimentation tank, a homogenizing conditioning tank, a wet catalytic oxidation device and a biological reactor.

[0007] The outlet of the first water collecting tank is connected with the inlet of the resin adsorption tower through a security filter, the outlet of the resin adsorption tower is divided into two routes, one of which is connected with the inlet of the homogenizing tank, and the other is connected with the inlet of the biological reactor; the outlet of the second water collecting tank is connected with the inlet of the coagulation sedimentation tank, the outlet of the coagulation sedimentation tank is connected with the inlet of the homogenizing tank, the outlet of the homogenizing tank is connected with the inlet of the wet catalytic oxidation device, the outlet of the wet catalytic oxidation device is connected with the inlet of the biological reactor, and the outlet of the biological reactor is connected with the zero-emission system of the power plant.

[0008] The outlet of the resin adsorption tower is divided into two routes through a flow divider.

[0009] A pH monitor is arranged in the first water collecting tank.

[0010] A pH monitor is arranged in the coagulation sedimentation tank.

[0011] A stirring device is arranged at the bottom of the homogenizing tank.

[0012] When working, the following steps are included:

[0013] 1) The equipment cleaning wastewater is collected in the first water collecting tank, and the pH is adjusted to neutral, then the impurities are filtered out through a security filter, and then the wastewater is sent into the resin adsorption tower for adsorption to remove the organic amine in the wastewater;

[0014] 2) The pH is adjusted to neutral, then the impurities are filtered out through a security filter, and then the wastewater is sent into the resin adsorption tower for adsorption to remove the organic amine in the wastewater;

[0015] 2) The solution purification wastewater is collected in the second water collecting tank, then enters the coagulation sedimentation tank to remove the colority and part of the pollutants in the wastewater, and after the coagulation reaction is completed, the pH is adjusted to 6-7 for sedimentation;

[0016] 3) The wastewater output by the resin adsorption tower is divided into two routes, one of which directly enters the biological reactor, and the other enters the homogenizing tank, and the supernatant output by the coagulation sedimentation tank enters the homogenizing tank for mixing;

[0017] 4) The wastewater output by the homogenizing tank enters the wet catalytic oxidation device for catalytic oxidation in the wet catalytic oxidation device;

[0018] 5) The wastewater output by the wet catalytic oxidation device enters the biological reactor for biological reaction.

[0019] The salt content of the water output by the homogenizing tank is less than 5%.

[0020] The operation process of step 4) is as follows:

[0021] The wastewater output by the homogenizing conditioning tank enters a wet catalytic oxidation device, in which the wastewater is heated to 250-280 DEG C, and then the pollutants in the wastewater are oxidized and degraded under the action of a catalyst.

[0022] The operation process of step 5) is as follows:

[0023] The wastewater output by the wet catalytic oxidation device enters a biological reactor, and then enters an anaerobic reaction zone, an anoxic reaction zone and an aerobic reaction zone in sequence, so that the organic amine, the organic amine derivative and the inorganic salt in the wastewater are further removed through the autotrophic or heterotrophic process of sulfate-reducing bacteria, nitrifying bacteria and denitrifying bacteria, and the COD in the wastewater is also removed.

[0024] The coagulant is a compounded agent of magnesium salt, iron salt, aluminum salt or high molecular polymer.

[0025] The present application has the following beneficial effects:

[0026] The organic amine carbon capture wastewater treatment system for power plants provided by the present application can remove the organic amine, the organic amine derivative and various inorganic salts in the organic amine carbon capture wastewater of the power plant through the integration of filtration, resin adsorption, coagulation sedimentation, wet catalytic oxidation and biological reaction, has high treatment efficiency, simple process, can effectively remove the COD and the salt content of the organic amine carbon capture wastewater of the power plant, and the treated wastewater can meet the requirements of the subsequent zero-emission system of the power plant. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The figure is a system structure diagram of the present application.

[0028] 1 is a first water collecting tank, 2 is a security filter, 3 is a resin adsorption tower, 4 is a flow divider, 5 is a second water collecting tank, 6 is a coagulation sedimentation tank, 7 is a homogenizing conditioning tank, 8 is a wet catalytic oxidation device, and 9 is a biological reactor. DETAILED DESCRIPTION

[0029] In order to enable personnel in the technical field to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments, and are not intended to limit the scope of the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts should belong to the scope of protection of the present application.

[0030] The structural schematic diagram according to the disclosed embodiment of the present application is shown in the accompanying drawings. The drawings are not drawn to scale, in which some details are enlarged for the purpose of clear expression, and some details can be omitted. The shapes of various regions, layers and the relative size and position relationship therebetween shown in the drawings are only exemplary, and in practice, they can be deviated due to manufacturing tolerance or technical limitation, and the regions / layers with different shapes, sizes and relative positions can be additionally designed according to actual needs by those skilled in the art.

[0031] Reference Figure 1 The organic amine carbon capture wastewater treatment system for power plants comprises a first water collecting tank 1, a security filter 2, a resin adsorption tower 3, a flow divider 4, a second water collecting tank 5, a coagulation sedimentation tank 6, a homogenizing adjustment tank 7, a wet catalytic oxidation device 8 and a biological reactor 9.

[0032] The outlet of the first water collecting tank 1 is connected to the inlet of the security filter 2 and the resin adsorption tower 3, the outlet of the resin adsorption tower 3 is divided into two paths through the flow divider 4, one of which is connected to the inlet of the homogenizing adjustment tank 7, and the other is connected to the inlet of the biological reactor 9; the outlet of the second water collecting tank 5 is connected to the inlet of the coagulation sedimentation tank 6, the outlet of the coagulation sedimentation tank 6 is connected to the inlet of the homogenizing adjustment tank 7, the outlet of the homogenizing adjustment tank 7 is connected to the inlet of the wet catalytic oxidation device 8, the outlet of the wet catalytic oxidation device 8 is connected to the inlet of the biological reactor 9, and the outlet of the biological reactor 9 is connected to the zero emission system of the power plant.

[0033] The working method of the organic amine carbon capture wastewater treatment system for power plants comprises the following steps:

[0034] 1) The equipment cleaning wastewater is collected in the first water collecting tank 1, and the pH is adjusted to neutral by using a sulfuric acid solution with a mass concentration of 98%, and then the impurities are filtered out by the security filter 2 and sent to the resin adsorption tower 3 for adsorption for 9-12 hours to remove the organic amine in the wastewater. The adsorption device is provided with an additional elution device.

[0035] 2) The solution purification wastewater is collected in the second water collecting tank 5, and then enters the coagulation sedimentation tank 6 to remove the colority and part of the pollutants in the wastewater, wherein the coagulant used in the coagulation sedimentation tank 6 is a compounded reagent mainly composed of magnesium salt, iron salt, aluminum salt and high molecular polymer, and after the coagulation reaction is completed, the pH is adjusted to 6-7 by using a sodium hydroxide solution with a mass concentration of 40%, and then the sedimentation is performed.

[0036] 3) The wastewater output from the resin adsorption tower 3 is divided into two paths, one of which is directly introduced into the biological reactor 9, and the other is introduced into the homogenizing adjustment tank 7. The supernatant from the coagulation sedimentation tank 6 is introduced into the homogenizing adjustment tank 7 for mixing. The salt content of the mixed wastewater is less than 5%, which avoids affecting the treatment efficiency of the subsequent wet catalytic oxidation technology.

[0037] 4) The wastewater output from the homogenizing adjustment tank 7 is introduced into the wet catalytic oxidation device 8. In the wet catalytic oxidation device 8, the wastewater is heated to 250-280℃ and the pressure is 2-8 MPa. Under the action of the catalyst, the pollutants in the wastewater are oxidized and degraded. In this stage, 70% of the COD in the wastewater is removed.

[0038] 5) The wastewater output from the wet catalytic oxidation device 8 is introduced into the biological reactor 9, and then sequentially introduced into the anaerobic reaction zone, anoxic reaction zone and aerobic reaction zone. Through the autotrophic or heterotrophic process of sulfate-reducing bacteria, nitrifying bacteria and denitrifying bacteria, organic amines, organic amine derivatives and inorganic salts in the wastewater are further removed, and the COD in the wastewater is also removed, which avoids affecting the subsequent zero-emission system.

[0039] In this embodiment, in step 1), the impurities in the equipment cleaning wastewater are mechanically filtered by the security filter 2.

[0040] In this embodiment, the pH monitor is arranged in the first water collecting tank 1. The pH value of the wastewater is adjusted to neutral in the first water collecting tank 1, and then sent to the resin adsorption tower 3 for adsorption treatment to remove organic amines in the equipment cleaning wastewater.

[0041] In this embodiment, the pH monitor is arranged in the coagulation sedimentation tank 6. The coagulant is a compound agent mainly composed of magnesium salt, iron salt, aluminum salt and high molecular polymer, which mainly treats the colority of the wastewater.

[0042] In this embodiment, the bottom of the homogenizing adjustment tank 7 is provided with a stirring device.

[0043] In this embodiment, the water quantity of the effluent from the resin adsorption tower 3 entering the homogenizing adjustment tank 7 needs to meet the requirement that the salt content of the effluent from the homogenizing adjustment tank 7 is less than 5%.

[0044] In the wet catalytic oxidation device 8, the wet oxidation technology is adopted to perform the reaction under the conditions of high temperature and high pressure. Oxygen oxidizes and decomposes the organic pollutants in the wastewater to remove part of the COD in the wastewater. The reaction temperature of the wastewater is controlled between 250-280℃ by the heat exchanger and heating device. This temperature range is beneficial to the decomposition of organic amine substances. The reacted wastewater needs to be cooled by the condenser before being sent into the biological reactor 9.

[0045] In the bioreactor 9, the wastewater sent by the wet catalytic oxidation device 8 is mixed with the wastewater sent by the shunt 4, and then sequentially passes through the anaerobic, anoxic and aerobic processes. In the anaerobic stage, the heterotrophic sulfate-reducing bacteria reduce the original sulfate and sulfite in the wastewater and consume the organic matter in the wastewater; in the anoxic stage, the autotrophic denitrifying bacteria reduce the original nitrate and nitrite in the wastewater generated in the previous stage to release ammonia gas; in the aerobic stage, the amine is oxidized to nitrate and nitrite; the mixed liquid in the aerobic tank is refluxed back to the anoxic tank.

[0046] It should be noted that the present application integrates several process technologies to remove organic amines, organic amine derivatives and various inorganic salts in the organic amine carbon capture wastewater of the power plant, has high treatment efficiency, simple process, realizes effective removal of the COD and salt content of the organic amine carbon capture wastewater of the power plant, and the treated wastewater can stably meet the requirements of the subsequent zero-emission system of the power plant.

[0047] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: the specific embodiments of the present application can still be modified or replaced by the equivalent, without departing from the spirit and scope of the present application, any modification or equivalent replacement, which should be covered within the protection scope of the claims of the present application.

Claims

1. A wastewater treatment system for capturing organic amine carbon in power plants, characterized in that, It includes a No. 1 water collection tank (1), a security filter (2), a resin adsorption tower (3), a diverter (4), a No. 2 water collection tank (5), a coagulation sedimentation tank (6), a homogenization equalization tank (7), a wet catalytic oxidation device (8), and a bioreactor (9); The outlet of the No. 1 water collection tank (1) is connected to the inlet of the resin adsorption tower (3) via the security filter (2). The outlet of the resin adsorption tower (3) is divided into two paths, one of which is connected to the inlet of the homogenization equalization tank (7), and the other is connected to the inlet of the bioreactor (9). The outlet of the No. 2 water collection tank (5) is connected to the inlet of the coagulation sedimentation tank (6). The outlet of the coagulation sedimentation tank (6) is connected to the inlet of the homogenization equalization tank (7). The outlet of the homogenization equalization tank (7) is connected to the inlet of the wet catalytic oxidation device (8). The outlet of the wet catalytic oxidation device (8) is connected to the inlet of the bioreactor (9). The outlet of the bioreactor (9) is connected to the zero-emission system of the power plant. The following steps are included when working: 1) The equipment cleaning wastewater is collected in the No. 1 collection tank (1), and the pH is adjusted to neutral. After the impurities are filtered out by the security filter (2), it is sent to the resin adsorption tower (3) for adsorption to remove organic amines in the wastewater. 2) The wastewater from the solution purification is collected in the No. 2 collection tank (5) and then enters the coagulation sedimentation tank (6) to remove the color and some pollutants from the wastewater. After the coagulation reaction is completed, the pH is adjusted to 6-7 and sedimentation is carried out. 3) The wastewater output from the resin adsorption tower (3) is divided into two streams. One stream goes directly into the bioreactor (9), and the other stream goes into the homogenization and conditioning tank (7). The supernatant output from the coagulation sedimentation tank (6) is mixed in the homogenization and conditioning tank (7). 4) The wastewater output from the equalization tank (7) enters the wet catalytic oxidation device (8) and undergoes catalytic oxidation in the wet catalytic oxidation device (8); 5) The wastewater output from the wet catalytic oxidation device (8) enters the bioreactor (9) for biological reaction.

2. The wastewater treatment system for organic amine carbon capture in power plants according to claim 1, characterized in that, The outlet of the resin adsorption tower (3) is divided into two paths after passing through the diverter (4).

3. The wastewater treatment system for capturing organic amine carbon in power plants according to claim 1, characterized in that, A pH monitor is installed in the No. 1 water collection tank (1).

4. The wastewater treatment system for capturing organic amine carbon in power plants according to claim 1, characterized in that, The coagulation sedimentation tank (6) is equipped with a pH monitor.

5. The wastewater treatment system for capturing organic amine carbon in power plants according to claim 1, characterized in that, The bottom of the homogenization tank (7) is equipped with a stirring device.

6. The wastewater treatment system for capturing organic amine carbon in power plants according to claim 1, characterized in that, The salinity of the effluent from the equalization tank (7) is less than 5%.

7. The wastewater treatment system for capturing organic amine carbon in power plants according to claim 1, characterized in that, The operation process for step 4) is as follows: Wastewater from the equalization tank (7) enters the wet catalytic oxidation device (8). In the wet catalytic oxidation device (8), the wastewater is heated to 250℃-280℃, and the pollutants in the wastewater are oxidized and degraded under the action of the catalyst.

8. The wastewater treatment system for organic amine carbon capture in power plants according to claim 1, characterized in that, The operation process for step 5) is as follows: Wastewater from the wet catalytic oxidation unit (8) enters the bioreactor (9), and then sequentially enters the anaerobic reaction zone, the anoxic reaction zone and the aerobic reaction zone. Through the autotrophic or heterotrophic processes of nitrifying bacteria, denitrifying bacteria and sulfate-reducing bacteria, organic amines, organic amine derivatives and inorganic salts in the wastewater are further removed, while COD in the wastewater is also removed.

9. The wastewater treatment system for capturing organic amine carbon in power plants according to claim 1, characterized in that, The coagulant is a compound of magnesium salts, iron salts, aluminum salts or high molecular weight polymers.

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