A flue gas carbon neutralization device for thermal power plants

Abstract

The present invention discloses a flue gas carbon neutralization device for thermal power plants, which relates to the field of flue gas carbon neutralization devices for thermal power plants. The device includes an absorption tank, a reactor, and a concentration device. The inlet of the absorption tank is used for introducing flue gas. The absorption tank is used for containing an absorption liquid. The outlet of the absorption tank is communicated with the inlet of the reactor. The outlet of the reactor is communicated with the inlet of the concentration device. The absorption tank can absorb carbon dioxide in the flue gas through the absorption liquid. The reactor can catalyze the absorption liquid and the flue gas after absorbing carbon dioxide to carry out a photoelectrocatalytic reduction reaction to generate organic substances. The concentration device is used for concentrating the absorption liquid to form a resource product. The flue gas carbon neutralization device in the present invention does not need to purify carbon dioxide, integrates carbon dioxide capture and catalytic synthesis, reduces the process flow and investment cost, and can realize and reduce the cost of carbon capture, utilization and storage.

Description

Technical Field

[0001] The present invention relates to the field of carbon dioxide treatment systems, and particularly to a carbon neutralization device for flue gas in thermal power plants. Background Art

[0002] CCUS (Carbon Capture, Utilization and Storage) is one of the technical options to achieve future emission reduction goals at the lowest economic cost. In existing CCUS, the carbon dioxide catalytic organic synthesis process requires the purification of carbon dioxide, increasing the process flow and cost. Summary of the Invention

[0003] The purpose of the present invention is to provide a carbon neutralization device for flue gas in thermal power plants to solve the problems existing in the above-mentioned prior art, and to be able to achieve and reduce the costs of carbon dioxide capture, catalytic synthesis and resource recovery in flue gas.

[0004] To achieve the above purpose, the present invention provides the following solutions:

[0005] The present invention provides a carbon neutralization device for flue gas in thermal power plants, including an absorption tank, a reactor and a concentration device. The inlet of the absorption tank is used to introduce flue gas, the absorption tank is used to hold an absorption liquid, the outlet of the absorption tank is connected to the inlet of the reactor, the outlet of the reactor is connected to the inlet of the concentration device. The absorption tank can absorb carbon dioxide in the flue gas through the absorption liquid, the reactor can catalyze the absorption liquid and the flue gas after absorbing carbon dioxide to carry out a photoelectrocatalytic reduction reaction to generate organic substances, and the concentration device is used to concentrate the absorption liquid to form a resource product.

[0006] Preferably, the reactor is a photoelectrocatalytic reactor, and the electrode of the photoelectrocatalytic reactor is a three-dimensional electrode.

[0007] Preferably, the three-dimensional electrode includes electrode particles and catalytic particles. Both the electrode particles and the catalytic particles are electrically connected to a wire. The surface of the electrode particles is provided with a catalyst layer to form catalytic particles. The number of the catalytic particles accounts for 50%-80% of the total number of the catalytic particles and the electrode particles.

[0008] Preferably, the absorption tank further includes a circulation inlet, the reactor further includes a circulation outlet. The reactor can catalyze the absorption liquid after absorbing carbon dioxide to carry out a reduction reaction and regenerate the absorption liquid. The regenerated absorption liquid can enter the absorption tank through the circulation outlet of the reactor and the circulation inlet of the absorption tank to re-absorb carbon dioxide.

[0009] Preferably, it further includes a heat exchanger. The inlet of the heat exchanger is used to introduce flue gas, the heat exchanger is used to cool the flue gas, and the outlet of the heat exchanger is connected to the absorption tank.

[0010] Preferably, an elution tower is further included. The inlet of the elution tower is communicated with the outlet of the heat exchanger, and the outlet of the elution tower is communicated with the absorption tank. The elution tower is used to remove dust particles and sulfur-containing compounds in the flue gas. A first demisting device is arranged at the outlet of the elution tower, and the first demisting device is used to remove the droplets in the flue gas discharged from the outlet of the elution tower.

[0011] Preferably, a booster fan is arranged between the elution tower and the absorption tank, and the booster fan is used to increase the pressure of the flue gas entering the absorption tank.

[0012] Preferably, a second demisting device is further included. The second demisting device is arranged at the exhaust port of the reactor, and the second demisting device is used to remove the droplets in the flue gas discharged from the reactor.

[0013] Preferably, the heat exchanger has a cooling medium chamber. The concentration device further includes a circulation outlet and a circulation inlet. The circulation outlet and the circulation inlet are respectively communicated with the inlet and the outlet of the cooling medium chamber. The absorption liquid in the concentration device can enter the cooling medium chamber from the inlet of the cooling medium, and return to the concentration device from the outlet of the cooling medium chamber. When the absorption liquid flows through the cooling medium chamber, it can absorb the heat of the flue gas to reduce the temperature of the flue gas and increase the temperature of the absorption liquid.

[0014] Preferably, an alkali liquid adding device is further included. The alkali liquid adding device is communicated with the absorption tank, and the alkali liquid adding device is used to provide alkali liquid to the absorption tank.

[0015] The present invention has achieved the following technical effects compared with the prior art:

[0016] A carbon neutralization device for flue gas in a thermal power plant provided by the present invention can be applied to the carbon neutralization treatment of flue gas in a thermal power plant, but is not limited to the above-mentioned ultra-low emission flue gas carbon dioxide treatment, and can be used for any carbon dioxide treatment that requires treatment. It includes an absorption tank, a reactor and a concentration device. After the flue gas is introduced into the absorption tank, part of the flue gas is absorbed by the absorption liquid, and the unabsorbed flue gas and the absorption liquid form a gas-liquid mixture. The absorption liquid and the gas-liquid mixture enter the reactor together. The reactor catalyzes and reduces the carbon dioxide absorbed by the absorption liquid and the carbon dioxide in the gas-liquid mixture to generate organic substances. The reacted absorption liquid enters the concentration device, and the concentration device concentrates the absorption liquid to increase the concentration of organic substances in the absorption liquid, obtaining a resource product. The obtained resource product can be directly utilized or stored, thereby realizing carbon capture, utilization and storage. And the above treatment process does not require the purification of the flue gas, reducing the cost of carbon capture, utilization and storage. Description of the Drawings

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of a flue gas carbon neutralization device provided in the present invention;

[0019] Figure 2 It is a schematic structural diagram of a three-dimensional electrode provided by the present invention.

[0020] In the figure: 1 - heat exchanger; 2 - elution tower; 3 - absorption tank; 4 - reactor; 5 - concentration device; 6 - second demisting device; 7 - lye addition device; 8 - current collector; 9 - insulating layer; 10 - electrode particles. Specific embodiments

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] The purpose of the present invention is to provide a flue gas carbon neutralization device for a thermal power plant to solve the problems existing in the above-mentioned prior art and improve the treatment efficiency of carbon dioxide.

[0023] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] This embodiment provides a flue gas carbon neutralization device for a thermal power plant, as Figure 1-2As shown in the figure, it includes an absorption tank 3, a reactor 4 and a concentration device 5. The inlet of the absorption tank 3 is used to introduce flue gas. The absorption tank 3 is used to hold the absorption liquid. The outlet of the absorption tank 3 is connected to the inlet of the reactor 4, and the outlet of the reactor 4 is connected to the inlet of the concentration device 5. The absorption tank 3 can absorb carbon dioxide in the flue gas through the absorption liquid. The reactor 4 can catalyze the photo-electrocatalytic reduction reaction of the absorption liquid after absorbing carbon dioxide and the flue gas to generate organic substances. The concentration device 5 is used to concentrate the absorption liquid to form a resource product. After the flue gas is introduced into the absorption tank 3, part of the flue gas is absorbed by the absorption liquid, and the unabsorbed flue gas and the absorption liquid form a gas-liquid mixture. The absorption liquid and the gas-liquid mixture enter the reactor 4 together. The reactor 4 catalyzes the reduction reaction of the carbon dioxide absorbed by the absorption liquid and the carbon dioxide in the gas-liquid mixture to generate organic substances. The reacted absorption liquid enters the concentration device 5, and the concentration device 5 concentrates the absorption liquid to increase the concentration of organic substances in the absorption liquid and obtain a resource product. The obtained resource product can be directly utilized or stored, thereby realizing carbon capture, utilization and storage. And the above treatment process does not require the purification of the flue gas, reducing the cost of carbon capture, utilization and storage.

[0025] The utilization in this embodiment is that carbon dioxide can be recycled, which can generate economic benefits and is more operable in reality.

[0026] In this embodiment, the treatment of carbon dioxide in the flue gas does not require the purification of carbon dioxide, and it can integrate the selective capture and catalytic synthesis of carbon dioxide, reducing the process flow and investment cost.

[0027] In this embodiment, the reactor 4 is a photo-electrocatalytic reactor, and the electrodes of the photo-electrocatalytic reactor are three-dimensional electrodes. The three-dimensional electrodes can make the absorption liquid fully contact with the electrodes, make the reduction reaction in the absorption liquid more sufficient, and improve the treatment efficiency of carbon dioxide.

[0028] In this embodiment, the photo-electrochemical reactor includes a reaction chamber and a light source that provides energy. The electrodes are arranged in the reaction chamber. The outer side wall of the reaction chamber is made of a transparent material, and it is preferably made of one of acrylic and glass. In this embodiment, the light source is preferably a xenon lamp, which simulates sunlight for irradiation, and preferably the xenon lamp provides an AM 1.5 light source with an intensity of 100 mW / cm 2 for irradiation.

[0029] In this embodiment, the three-dimensional electrode includes a current collector 8 and an insulating layer 9. The current collector 8 has an electrode cavity, and at least one absorption liquid through-hole is opened on the side wall of the electrode cavity. The absorption liquid through-hole is used for the absorption liquid flowing in and out of the electrode cavity.

[0030] In this embodiment, the three-dimensional electrode includes electrode particles 10 and catalytic particles. Both the electrode particles 10 and the catalytic particles are electrically connected to a wire. A catalyst layer is provided on the surface of the electrode particles 10 to form the catalytic particles. The number of catalytic particles accounts for 50%-80% of the total number of catalytic particles and electrode particles 10. In this embodiment, it is only required that the electrode particles 10 carry the catalyst for the catalytic particles. In this embodiment, it is preferably to provide the catalyst on the surface of the electrode particles 10 to form the catalytic particles. The electrode particles 10 with a catalyst layer on the surface and the electrode particles 10 without a catalyst layer on the surface are uniformly mixed, so that the absorbent liquid can fully contact with the catalyst, giving full play to the effect of the catalyst and further improving the treatment efficiency of carbon dioxide. The electrode particles in this embodiment are all point-connected to the wire by the electrode particles.

[0031] In this embodiment, both the electrode particles 10 and the catalytic particles are disposed in the electrode cavity.

[0032] In this embodiment, the electrode particles 10 of the three-dimensional electrode can increase the contact area between the electrode and the absorbent liquid, increase the double-layer capacitance at the solid-liquid interface, reduce the mass transfer impedance, and improve the reaction rate and reaction efficiency of the catalytic reduction reaction in the reactor 4.

[0033] In this embodiment, the number of catalytic particles can account for 50%-80% of the number of electrode particles 10. Preferably, the number of catalytic particles accounts for 50% of the number of electrode particles 10. Preferably, the outer contour dimension of the electrode particles 10 is between 0.5 cm and 2 cm.

[0034] In this embodiment, the material of the current collector 8 can be a conductive electrode metal material, preferably one of titanium alloy, stainless steel, aluminum foil and nickel. The insulating layer 9 can be selected from polymer materials, preferably one of polypropylene, polyvinyl chloride, ABS engineering plastic and acrylic.

[0035] In this embodiment, the electrode particles 10 are made of high-strength carbon particles. After the carbon electrode particles 10 are loaded with the catalyst, the selectivity and singularity of the carbon dioxide reduction potential are realized, avoiding the interference of other impurity reduction reactions, thereby improving the treatment efficiency of carbon dioxide.

[0036] In this embodiment, the absorption tank 3 further includes a circulation inlet, and the reactor 4 further includes a circulation outlet. The reactor 4 can catalyze the reduction reaction of the absorption liquid after absorbing carbon dioxide and regenerate the absorption liquid. The regenerated absorption liquid can enter the absorption tank 3 through the circulation outlet of the reactor 4 and the circulation inlet of the absorption tank 3 to absorb carbon dioxide again. The circulation outlet of the reactor 4 is communicated with the circulation inlet of the absorption tank 3 to realize the circulation connection between the absorption tank 3 and the reactor 4. The flue gas and the absorption liquid form a gas-liquid mixture, and the absorption liquid can enter the reactor 4 through the outlet of the absorption tank 3. The flue gas and the absorption liquid in the reactor 4 can enter the absorption tank 3 through the circulation outlet and the circulation inlet, so that the flue gas and the absorption liquid can circulate in the absorption tank 3 and the reactor 4. The reactor 4 can catalyze the reduction reaction of the absorption liquid after absorbing carbon dioxide and regenerate the absorption liquid. The regenerated absorption liquid circulates into the absorption tank 3 and can repeatedly absorb carbon dioxide in the flue gas, improving the absorption efficiency of the absorption liquid and further improving the treatment efficiency of carbon dioxide.

[0037] The absorption liquid in this embodiment can be a liquid capable of absorbing carbon dioxide. In this embodiment, a weakly alkaline ionic liquid with a pH value between 7.2 and 8.5 is preferably used to improve the absorption capacity of the absorption liquid for carbon dioxide in the flue gas and facilitate the progress of the catalytic reaction. An aeration device is provided in the absorption tank 3 of this embodiment. The aeration device can make the flue gas entering the absorption tank 3 fully contact with the absorption liquid, so that the absorption liquid can fully absorb carbon dioxide in the flue gas and further improve the treatment efficiency of carbon dioxide.

[0038] In this embodiment, the absorption tank 3 can be sealed separately and further includes an internal pressurization device. After the absorption tank 3 absorbs the flue gas once, the absorption tank 3 is sealed, and then internal pressurization and aeration are carried out to make the flue gas entering the absorption tank 3 fully dissolve in the absorption liquid. Then, the unabsorbed flue gas and the absorption liquid are circulated in the absorption tank 3 and the reactor 4 to realize the cyclic absorption of carbon dioxide in the flue gas. When the carbon dioxide detection device in the reactor 4 detects that the mass content of carbon dioxide in the flue gas is reduced to no more than 1%, the flue gas in the reactor 4 is discharged from the reactor 4.

[0039] In this embodiment, a flue gas carbon neutralization device for a thermal power plant further includes a heat exchanger 1. The inlet of the heat exchanger 1 is used to introduce flue gas. The heat exchanger 1 is used to cool the flue gas. The outlet of the heat exchanger 1 is communicated with the absorption tank 3, and a temperature exchange liquid is provided in the heat exchanger 1. The heat exchanger 1 can reduce the temperature of the flue gas, facilitating the working temperature of the subsequent catalytic reduction reaction in the reactor 4 to be maintained within the normal range.

[0040] The initial temperature of the flue gas is 45°C - 70°C. After heat exchange between the temperature exchange liquid and the flue gas in the heat exchanger 1, the flue gas is discharged from the heat exchanger 1. In this embodiment, the over-current medium of the heat exchanger is preferably made of 2205 stainless steel.

[0041] In this embodiment, a flue gas carbon neutralization device for a thermal power plant further includes an elution tower 2. The inlet of the elution tower 2 is connected to the outlet of the heat exchanger 1, and the elution tower 2 is connected to an absorption tank 3. The elution tower 2 is used to remove dust particles and sulfur-containing compounds from the flue gas. The elution tower is provided with a first demisting device, and the first demisting device is arranged at the outlet of the elution tower. The first demisting device is used to remove the droplets from the flue gas discharged from the outlet of the elution tower. The flue gas cooled by heat exchange in the heat exchanger 1 enters the elution tower 2. The elution tower 2 can remove dust particles and some sulfur-containing compounds from the flue gas, so as to facilitate the absorption of carbon dioxide in the flue gas by the absorption liquid. In this embodiment, it is to prevent droplets from entering the absorption tank and diluting the absorption liquid, thereby reducing the absorption efficiency of the absorption liquid for carbon dioxide.

[0042] In this embodiment, the temperature of the flue gas discharged from the elution tower 2 is 20°C - 30°C, so as to facilitate the subsequent reactions of carbon dioxide absorption and reduction to have a suitable ambient temperature.

[0043] In this embodiment, a booster fan is arranged between the elution tower 2 and the absorption tank 3. The booster fan is used to increase the pressure of the flue gas entering the absorption tank 3. Increasing the pressure of the flue gas entering the absorption tank 3 is beneficial to the dissolution of carbon dioxide in the flue gas into the absorption liquid.

[0044] In this embodiment, a flue gas carbon neutralization device for a thermal power plant further includes a second demisting device 6. The second demisting device 6 is connected to the reactor 4. The reactor 4 is used to remove the droplets from the flue gas discharged from the reactor 4. The second demisting device 6 can retain the droplets containing harmful substances in the demister, and can prevent harmful substances from escaping into the atmosphere along with the flue gas.

[0045] In this embodiment, a concentration device 5 is further included. The concentration device 5 is connected to the drain outlet of the reactor 4. The concentration device 5 is used to concentrate the solution discharged from the reactor 4. When the organic matter in the absorption liquid reaches a specified amount, the absorption liquid is discharged from the reactor to the concentration device 5. The absorption liquid is concentrated in the concentration device 5. After concentration, desalinated water and concentrated liquid can be produced. The desalinated water can be used as the absorption liquid in the absorption tank 3. The concentrated liquid is subjected to drying and solidification treatment to produce crystal particles, or the concentrated liquid can be directly stored, which can be used as a resource product to realize the reuse of resources, thereby realizing the capture, conversion and storage of carbon dioxide in the flue gas of the thermal power plant and completing the resource-based reuse of carbon dioxide. In this embodiment, the concentration process of the concentration device 5 can be selected from one of high-pressure reverse osmosis, electrodialysis and membrane distillation.

[0046] In this embodiment, the specific resource products are related to the catalyst type and the design of the photoelectrocatalytic reaction. By selecting the catalyst, the selectivity and singularity of the carbon dioxide reduction potential are achieved, and the interference of other impurity reduction reactions is avoided.

[0047] In this embodiment, the heat exchanger 1 has a cooling medium chamber. The outlet and inlet of the concentration device 5 are respectively communicated with the inlet and outlet of the cooling medium chamber. The absorption liquid in the concentration device 5 can enter the cooling medium chamber from the inlet of the cooling medium and return to the concentration device 5 from the outlet of the cooling medium chamber. When the absorption liquid flows through the cooling medium chamber, it can absorb the heat of the flue gas to reduce the temperature of the flue gas and increase the temperature of the absorption liquid. By reducing the temperature of the flue gas through the heat exchanger 1, the water consumption in the elution tower 2 can be reduced, and the temperature of the flue gas can be reduced to a temperature suitable for the catalytic reaction, which can increase the catalytic reduction reaction of the photoelectrocatalytic device on the dissolution liquid. Taking the absorption liquid in the concentration device 5 as the temperature exchange liquid, when the temperature of the absorption liquid to be concentrated increases, the membrane flux of the concentrated liquid can be increased, and the operation cost of the membrane concentration equipment can be reduced.

[0048] In this embodiment, the initial temperature of the absorption liquid entering the cooling medium chamber is 10°C - 35°C. After heat exchange, the temperature of the flue gas drops to 40°C - 50°C, and the temperature of the liquid material rises to 35°C - 40°C.

[0049] In this embodiment, a flue gas carbon neutralization device for a thermal power plant further includes an alkali liquid adding device 7. The alkali liquid adding device 7 is communicated with the absorption tank 3, and the alkali liquid adding device 7 is used to provide alkali liquid into the absorption tank 3. When the alkalinity of the absorption liquid decreases, the alkali liquid adding device 7 can input alkali liquid into the absorption tank 3 to increase the alkalinity of the absorption liquid, preventing the absorption efficiency of carbon dioxide from decreasing due to the decrease in alkalinity of the absorption liquid.

[0050] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A flue gas carbon neutralization device for a thermal power plant, characterized in that: It includes an absorption tank, a reactor and a concentration device. The inlet of the absorption tank is used for introducing flue gas. The absorption tank is used for containing an absorption liquid. The outlet of the absorption tank is communicated with the inlet of the reactor. The outlet of the reactor is communicated with the inlet of the concentration device. The absorption tank can absorb carbon dioxide in the flue gas through the absorption liquid. The reactor can catalyze the photoelectrocatalytic reduction reaction of the absorption liquid and the flue gas after absorbing carbon dioxide to generate organic substances. The concentration device is used for concentrating the absorption liquid to form a resource product. The reactor is a photoelectrocatalytic reactor, and the electrode of the photoelectrocatalytic reactor is a three-dimensional electrode. The three-dimensional electrode includes electrode particles and catalytic particles. Both the electrode particles and the catalytic particles are electrically connected to a wire. A catalyst layer is arranged on the surface of the electrode particles to form catalytic particles. The number of the catalytic particles accounts for 50%-80% of the total number of the catalytic particles and the electrode particles. The absorption tank further includes a circulation inlet, and the reactor further includes a circulation outlet. The reactor can catalyze the reduction reaction of the absorption liquid after absorbing carbon dioxide and regenerate the absorption liquid. The regenerated absorption liquid can enter the absorption tank through the circulation outlet of the reactor and the circulation inlet of the absorption tank to absorb carbon dioxide again.

2. The flue gas carbon neutralization equipment for thermal power plants according to claim 1, characterized in that: It further includes a heat exchanger. The inlet of the heat exchanger is used for introducing flue gas. The heat exchanger is used for cooling the flue gas. The outlet of the heat exchanger is communicated with the absorption tank.

3. The flue gas carbon neutralization equipment for thermal power plants according to claim 2, characterized in that: It further includes an elution tower. The inlet of the elution tower is communicated with the outlet of the heat exchanger. The outlet of the elution tower is communicated with the absorption tank. The elution tower is used for removing dust particles and sulfur-containing compounds in the flue gas. A first demisting device is arranged at the outlet of the elution tower. The first demisting device is used for removing the droplets in the flue gas discharged from the outlet of the elution tower.

4. A flue gas carbon neutralization device for a thermal power plant according to claim 1, characterized in that: It further includes a second demisting device. The second demisting device is arranged at the exhaust port of the reactor. The second demisting device is used for removing the droplets in the flue gas discharged from the reactor.

5. The flue gas carbon neutralization device for a thermal power plant according to claim 2, characterized in that: The heat exchanger has a cooling medium chamber. The concentration device further includes a circulation outlet and a circulation inlet. The circulation outlet and the circulation inlet are respectively communicated with the inlet and the outlet of the cooling medium chamber. The absorption liquid in the concentration device can enter the cooling medium chamber from the inlet of the cooling medium and return to the concentration device from the outlet of the cooling medium chamber. When the absorption liquid flows through the cooling medium chamber, it can absorb the heat of the flue gas to reduce the temperature of the flue gas and increase the temperature of the absorption liquid.

6. The flue gas carbon neutralization equipment for a thermal power plant according to claim 3, characterized in that: A booster fan is arranged between the elution tower and the absorption tank. The booster fan is used for increasing the pressure of the flue gas entering the absorption tank.

7. The flue gas carbon neutralization device for a thermal power plant according to claim 1, wherein: It further includes an alkali solution adding device. The alkali solution adding device is communicated with the absorption tank. The alkali solution adding device is used for providing alkali solution to the absorption tank.

Images