Carbon dioxide absorption device and method

Abstract

The application relates to the technical field, in particular to a carbon dioxide absorption device and method, which comprises an absorption tower, an absorption liquid supply circuit, a primary absorption liquid circulation circuit and a controller; a smoke inlet is arranged at the bottom end of the absorption tower body, a smoke outlet is arranged at the top end of the absorption tower body, and a secondary absorption unit and a primary absorption unit are sequentially arranged in the absorption tower body from top to bottom; the secondary absorption unit comprises a second liquid distributor, an ultrasonic atomizer, a high-voltage static generator and a secondary absorption layer which are sequentially and spacedly arranged from top to bottom; the absorption liquid supply circuit is located outside the absorption tower body; the primary absorption unit comprises a first liquid collector, a positive electrode plate and a first liquid distributor which are sequentially and spacedly arranged from top to bottom; the primary absorption unit comprises a primary absorption layer; and the primary absorption liquid circulation circuit is located outside the absorption tower body. The application can effectively improve the CO2 absorption efficiency and reduce amine escape.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon dioxide absorption, in particular to a carbon dioxide absorption device and method. BACKGROUND

[0002] High-emission industries such as thermal power generation and steel smelting are the main sources of carbon emissions, and efficient and feasible carbon capture technologies are urgently needed. At present, amine absorption technology has become the mainstream technology for large-scale low-concentration CO2 capture due to its high process maturity, perfect material and equipment supply chain, and rich engineering application cases. This technology uses amine compounds (such as methyldiethanolamine MDEA and diethanolamine DEA) as the absorbent solution system to capture and separate CO2 through gas-liquid phase change.

[0003] However, the traditional amine absorption technology still faces the following key problems in engineering application:

[0004] 1. Low mass transfer efficiency and large equipment size

[0005] In the traditional spray absorption tower, the particle size of the absorption liquid is large (usually 100-500 μm), which leads to small gas-liquid contact area, significant liquid film resistance, long CO2 mass transfer path and low rate. In order to meet the capture efficiency requirement, a large absorption tower with large diameter and height (usually tower diameter ≥ 10 m, tower height ≥ 30 m) is needed, which significantly increases the equipment investment and land area.

[0006] 2. Amine escape and environmental pollution risk

[0007] During the absorption-desorption cycle, the flue gas temperature increases after decarbonization (usually to 50-80℃), which reduces the solubility and carries part of the unreacted amine components, degradation products and water into the subsequent system, causing amine loss, and also causing equipment corrosion, secondary pollution and rising operating costs.

[0008] To solve the above problems, researchers in the field have proposed various improvement schemes, but there are still limitations:

[0009] Patent CN116850755A proposes to form irregular liquid films by acoustic vibration of the packing layer, which can slightly increase the gas-liquid contact area and produce micro-turbulence, but the particle size of the absorption liquid is not changed, the mass transfer efficiency is limited, and amine escape cannot be effectively inhibited;

[0010] Patent CN115350567A uses high-speed centrifugal separation to recover microdroplets in flue gas, which can reduce amine loss, but the centrifugal process has high energy consumption, and the capture efficiency for liquid droplets with particle size < 10 μm is not good;

[0011] Patent CN118543225B disturbs the flue gas flow field by rotating / moving the filler layer, although it enhances gas-liquid collision contact, but needs complex mechanical structure to support the movement of multiple layers of fillers, and has poor long-term reliability, and the mass transfer efficiency is limited;

[0012] Patent CN116020256A uses pressure difference to form turbulent flow to prolong gas-liquid contact time, but the mixer structure increases the pressure resistance of the absorption tower, limiting its application in large flow conditions.

[0013] In summary, the existing technical solutions have not broken through the core bottleneck of traditional amine absorption technology, i.e. how to achieve the synergistic optimization of efficient mass transfer and low amine escape in smaller equipment size. With the urgent need for low-carbon transformation of power generation, steel and other industries, developing an amine absorption technology method with high absorption efficiency and compact equipment structure has become a technical problem that needs to be solved in this field. SUMMARY

[0014] The purpose of the present application is to provide a carbon dioxide absorption device and method that can effectively increase the processing gas volume, improve the CO2 absorption efficiency, and reduce amine escape.

[0015] To achieve the above-mentioned purpose, a carbon dioxide absorption device adopted by the present application comprises an absorption tower, an absorption liquid supply circuit, a primary absorption liquid circulation circuit, and a controller.

[0016] The absorption tower comprises an absorption tower body, a primary absorption unit, and a secondary absorption unit. The bottom end of the absorption tower body is provided with a flue gas inlet, and the top end of the absorption tower body is provided with a flue gas outlet. The secondary absorption unit and the primary absorption unit are sequentially arranged in the absorption tower body from top to bottom.

[0017] The secondary absorption unit comprises a second liquid distributor, an ultrasonic atomizer, a high-voltage static generator, and a secondary absorption layer, which are sequentially and spacedly arranged from top to bottom. The absorption liquid supply circuit is located outside the absorption tower body, and the two ends of the absorption liquid supply circuit are respectively an inlet end and a supply end. The supply end of the absorption liquid supply circuit is connected with the second liquid distributor. A secondary feeding pump is arranged on the absorption liquid supply circuit for pumping the absorption liquid in the absorption liquid supply circuit from the inlet end to the supply end.

[0018] The primary absorption unit comprises a first liquid collector, a positive electrode plate, a first liquid distributor, and a primary absorption layer arranged in sequence from top to bottom at intervals, the primary absorption liquid circulation loop is located outside the absorption tower body, and two ends of the primary absorption liquid circulation loop are respectively a liquid inlet end and a liquid supply end, the liquid inlet end of the primary absorption liquid circulation loop is connected with the first liquid collector, the liquid supply end is connected with the first liquid distributor, and a primary feeding pump for pumping the absorption liquid in the first liquid collector from the liquid inlet end to the liquid supply end is arranged on the primary absorption liquid circulation loop.

[0019] The controller is electrically connected with the ultrasonic atomizer, the high-voltage electrostatic generator, the positive electrode plate, the primary feeding pump, and the secondary feeding pump.

[0020] As a preferred technical solution, a secondary cooler is further arranged on the absorption liquid supply loop, one end of the secondary cooler is connected with the secondary feeding pump, and the other end is connected with the liquid supply end of the absorption liquid supply loop.

[0021] As a preferred technical solution, a primary cooler is further arranged on the primary absorption liquid circulation loop, one end of the primary cooler is connected with the primary feeding pump, and the other end is connected with the liquid supply end of the absorption liquid supply loop.

[0022] As a preferred technical solution, the carbon dioxide absorption device further comprises a washing water supply loop, and the absorption tower further comprises an amine recovery unit,

[0023] The amine recovery unit comprises a third liquid distributor, an amine recovery layer, and a second liquid collector arranged in sequence from top to bottom at intervals, the second liquid collector is used for storing washing water, the washing water supply loop is located outside the absorption tower body, and two ends of the washing water supply loop are respectively a liquid inlet end and a liquid supply end, the liquid inlet end of the washing water supply loop is connected with the second liquid collector, the liquid supply end is connected with the third liquid distributor, and a tertiary feeding pump for pumping the washing water in the second liquid collector from the liquid inlet end to the liquid supply end is arranged on the washing water supply loop.

[0024] As a preferred technical solution, a tertiary cooler is further arranged on the washing water supply loop, one end of the tertiary cooler is connected with the tertiary feeding pump, and the other end is connected with the liquid supply end of the washing water supply loop.

[0025] As a preferred technical solution, the carbon dioxide absorption device further comprises a scrubbing water recovery circuit, the scrubbing water recovery circuit is located outside the absorption tower body, and two ends of the scrubbing water recovery circuit are respectively an inlet end and a liquid supply end; the inlet end of the scrubbing water recovery circuit is connected with the three-stage cooler, and the liquid supply end is connected with the inlet end of the absorption liquid supply circuit.

[0026] As a preferred technical solution, the carbon dioxide absorption device further comprises a plurality of component monitoring devices, the plurality of component monitoring devices are respectively arranged at the inlet end of the absorption liquid supply circuit and the inlet end of the scrubbing water supply circuit; the plurality of component monitoring devices are respectively used for monitoring the water and amine component contents of the absorption liquid and the scrubbing water in the absorption liquid supply circuit and the scrubbing water supply circuit.

[0027] As a preferred technical solution, the carbon dioxide absorption device further comprises a desorption tower, an absorption liquid desorption circuit, and an absorption liquid recovery circuit,

[0028] The desorption tower comprises a desorption tower body and a desorption unit; the top end of the desorption tower body is provided with a gas outlet, and the bottom end of the desorption tower body is provided with a liquid outlet; and the desorption unit is arranged in the desorption tower body.

[0029] The desorption unit comprises a fourth liquid distributor, a two-stage packing layer, a one-stage packing layer, and a third liquid collector which are sequentially and spacedly arranged from top to bottom; the absorption liquid desorption circuit and the absorption liquid recovery circuit are located outside the desorption tower body, and two ends of the absorption liquid desorption circuit and the absorption liquid recovery circuit are respectively an inlet end and a liquid supply end; the inlet end of the absorption liquid desorption circuit is connected with the bottom of the absorption tower body, the liquid supply end is connected with the fourth liquid distributor, a four-stage feed pump is arranged on the absorption liquid desorption circuit and is used for pumping the absorption liquid at the bottom of the absorption tower body from the inlet end to the fourth liquid distributor; the inlet end of the absorption liquid recovery circuit is connected with the bottom of the desorption tower body, the liquid supply end is connected with the inlet end of the absorption liquid supply circuit, and a five-stage feed pump is arranged on the absorption liquid recovery circuit and is used for pumping the absorption liquid at the bottom of the desorption tower body from the bottom of the desorption tower body to the inlet end of the absorption liquid supply circuit.

[0030] As a preferred technical solution, a heat exchanger is further arranged on the absorption liquid desorption circuit, the heat exchanger is arranged between the four-stage feed pump and the fourth liquid distributor, one end of the heat exchanger is connected with the liquid supply end of the absorption liquid desorption circuit, and the other end is connected with the inlet end of the absorption liquid recovery circuit.

[0031] The application also provides a carbon dioxide absorption method using the carbon dioxide absorption device described above, comprising: a controller controls the start of a primary feed pump, a secondary feed pump, a positive electrode plate, an ultrasonic atomizer and a high-voltage electrostatic generator, controls the primary feed pump to transport the absorption liquid from the liquid inlet end of the absorption liquid supply circuit to the liquid supply end of the absorption liquid supply circuit, controls the ultrasonic atomizer to atomize the absorption liquid, controls the high-voltage electrostatic generator to negatively charge the atomized absorption liquid, controls the positive electrode plate to make the negatively charged absorption liquid fall to the liquid inlet end of the primary absorption liquid circulation circuit, and controls the secondary feed pump to transport the absorption liquid from the liquid inlet end of the primary absorption liquid circulation circuit to the liquid supply end of the primary absorption liquid circulation circuit.

[0032] The carbon dioxide absorption device provided by the technical scheme has the following beneficial effects compared with the prior art:

[0033] 1. The ultrasonic atomizer is used to refine the particle size of the absorption liquid, effectively increases the gas-liquid contact area and enhances the mass transfer efficiency; and the high-voltage electrostatic generator is used to negatively charge the absorption liquid, the negative charge can promote the protonated amine group (-NH3+) in the absorption liquid to change in the direction of non-protonation, so that the absorption liquid has higher nucleophilicity and is more likely to react with CO2; and the increase of the absorption efficiency greatly increases the processing gas volume of the device, so that more flue gas can be processed without increasing the size of the device and the circulation amount of the absorption liquid, thereby reducing the cost investment and operation consumption.

[0034] 2. The primary absorption layer and the secondary absorption layer are arranged to form a multi-stage absorption structure, the secondary absorption layer uses atomized and charged absorption liquid, and the unsaturated absorption liquid is returned to the primary absorption layer after cooling to continue the reaction, so that the graded absorption and the step-by-step use of the absorption liquid are realized.

[0035] 3. The positively charged electrode plate is used to make the negatively charged absorption liquid flow downward under the superposition of the coulomb force and the gravity, so as to effectively reduce the amine escape; and the amine recovery unit is used to spray washing water to recover the amine components, degradation products and water in the decarbonized flue gas, so as to further reduce the amine escape and avoid pollution to the environment.

[0036] 4. The pipelines and valves are connected to form a closed circulation system, so as to effectively reduce the land occupation area and the operation complexity of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The figure is a structural schematic diagram of the embodiment of the application.

[0038] Wherein: 1, absorption tower; 11, absorption tower body; 110, smoke inlet; 111, smoke outlet; 12, first absorption unit; 120, first liquid collector; 121, positively charged electrode plate; 122, first liquid distributor; 123, first absorption layer; 13, second absorption unit; 130, second liquid distributor; 131, ultrasonic atomizer; 132, high-voltage electrostatic generator; 133, second absorption layer;

[0039] 2, absorption liquid supply circuit; 21, second feed pump; 22, second cooler; 23, liquid storage tank; 24, water replenisher; 25, amine replenisher;

[0040] 3, first absorption liquid circulation circuit; 31, first feed pump; 32, first cooler;

[0041] 4, amine recovery unit; 41, third liquid distributor; 42, amine recovery layer; 43, second liquid collector;

[0042] 5, scrubbing water supply circuit; 51, third feed pump; 52, third cooler;

[0043] 6, scrubbing water recovery circuit;

[0044] 7, component monitoring device;

[0045] 8, desorption tower; 80, desorption tower body; 81, fourth liquid distributor; 82, second packing layer; 83, first packing layer; 84, third liquid collector; 85, gas outlet; 86, reboiler;

[0046] 9, absorption liquid desorption circuit; 91, fourth feed pump; 92, heat exchanger;

[0047] 10, absorption liquid recovery circuit; 101, fifth feed pump. DETAILED DESCRIPTION

[0048] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0049] In the description of the present application, it should be understood that the terms "front", "back", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, in the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0050] See Figure 1 A carbon dioxide absorption device provided by an embodiment of the present application comprises an absorption tower 1, an absorption liquid supply circuit 2, a primary absorption liquid circulation circuit 3 and a controller.

[0051] The absorption tower 1 comprises an absorption tower body 11, a primary absorption unit 12 and a secondary absorption unit 13, the bottom end of the absorption tower body 11 is provided with a smoke inlet 110, the top end of the absorption tower body 11 is provided with a smoke outlet 111, and the secondary absorption unit 13 and the primary absorption unit 12 are sequentially arranged in the absorption tower body 11 from top to bottom.

[0052] The secondary absorption unit 13 comprises a second liquid distributor 130, an ultrasonic atomizer 131, a high-voltage static generator 132 and a secondary absorption layer 133 which are sequentially and spacedly arranged from top to bottom, the absorption liquid supply circuit 2 is located outside the absorption tower body 11, and the two ends of the absorption liquid supply circuit 2 are respectively an inlet end and a supply end, the supply end of the absorption liquid supply circuit 2 is connected with the second liquid distributor 130, and a secondary feeding pump 21 is arranged on the absorption liquid supply circuit 2 for pumping the absorption liquid in the absorption liquid supply circuit 2 from the inlet end to the supply end.

[0053] The primary absorption unit 12 comprises a first liquid collector 120, a positively charged electrode plate 121, a first liquid distributor 122 and a primary absorption layer 123 which are sequentially and spacedly arranged from top to bottom, the primary absorption liquid circulation circuit 3 is located outside the absorption tower body 11, and the two ends of the primary absorption liquid circulation circuit 3 are respectively an inlet end and a supply end, the inlet end of the primary absorption liquid circulation circuit 3 is connected with the first liquid collector 120, the supply end is connected with the first liquid distributor 122, and a primary feeding pump 31 is arranged on the primary absorption liquid circulation circuit 3 for pumping the absorption liquid in the first liquid collector 120 from the inlet end to the supply end.

[0054] The controller is electrically connected with the ultrasonic atomizer 131, the high-voltage static generator 132, the positively charged electrode plate 121, the primary feeding pump 31 and the secondary feeding pump 21 respectively.

[0055] In the embodiment, first, the spraying of the absorption liquid needs to be completed, the controller controls the ultrasonic atomizer 131, the high-voltage electrostatic generator 132, the positively charged electrode plate 121, the first-stage feed pump 31 and the second-stage feed pump 21 to start, the second-stage feed pump 21 extracts the absorption liquid from the liquid storage tank 23, enters the absorption liquid supply circuit 2 through the liquid inlet and delivers it to the liquid outlet, then the absorption liquid enters the second liquid distributor 130, is sprayed into the ultrasonic atomizer 131 for atomization, the atomized absorption liquid enters the high-voltage electrostatic generator 132 to be negatively charged, and the negatively charged absorption liquid enters the second-stage absorption layer 133; the absorption liquid in the second-stage absorption layer 133 falls into the first liquid collector 120 under the action of gravity and the positively charged electrode plate 121, the first-stage feed pump 31 extracts the absorption liquid from the first liquid collector 120, enters the first-stage absorption liquid circulation circuit 3 through the liquid inlet and delivers it to the liquid outlet, then the absorption liquid enters the first liquid distributor 122 and is sprayed into the first-stage absorption layer 123. Then, when the first-stage absorption layer 123 and the second-stage absorption layer 133 are filled with absorption liquid, the pretreated flue gas is introduced into the flue gas inlet 110 of the absorption tower 1, the flue gas enters the first-stage absorption layer 123 and the second-stage absorption layer 133 in turn and reacts with the absorption liquid, the absorption liquid absorbs CO2 in the flue gas, and the flue gas after two absorptions is discharged through the flue gas outlet 111 at the top of the absorption tower body.

[0056] On the one hand, the device sets the ultrasonic atomizer 131 to refine the particle size of the absorption liquid, significantly increases the surface area of the absorption liquid, and the small absorption liquid particles have a shorter diffusion path, small mass transfer resistance, higher absorption rate, improved utilization rate of the absorption liquid, and stronger uniformity of the distribution of the atomized absorption liquid in the tower, reducing the possibility of partial gas-liquid flow short circuit or dead zone in the traditional spraying in the absorption tower 1; on the other hand, the high-voltage electrostatic generator 132 is set to make the atomized absorption liquid negatively charged, and the positively charged electrode plate 121 is set below the first liquid collector 120 to make the negatively charged absorption liquid quickly flow downward under the superposition of the coulomb force and gravity, effectively reducing the amine escape. And the negative charge can promote the protonated amine group in the absorption liquid to change in the direction of unprotonation, so the negatively charged absorption liquid has higher nucleophilicity and is more likely to react with CO2, thereby having faster reaction speed and higher absorption efficiency.

[0057] Further, the absorption liquid supply circuit 2 is further provided with a secondary cooler 22, one end of the secondary cooler 22 is connected with the secondary feed pump 21, and the other end is connected with the liquid supply end of the absorption liquid supply circuit 2. Meanwhile, the primary absorption liquid circulation circuit 3 is further provided with a primary cooler 32, one end of the primary cooler 32 is connected with the primary feed pump 31, and the other end is connected with the liquid supply end of the absorption liquid supply circuit 2. The coolers are respectively arranged in the absorption liquid supply circuit 2 and the primary absorption liquid circulation circuit 3, before starting the device, the predetermined temperature of the cooling liquid is set, after starting the device, the cooling liquid entering the two circuits can be cooled by the coolers to the predetermined temperature, further improving the absorption efficiency of the cooling liquid to the CO2 in the high-temperature flue gas.

[0058] Further, the carbon dioxide absorption device further comprises a washing water supply circuit 5, the absorption tower 1 further comprises an amine recovery unit 4,

[0059] The amine recovery unit 4 comprises a third liquid distributor 41, an amine recovery layer 42, and a second liquid collector 43 arranged in sequence from top to bottom, the second liquid collector 43 is used for storing washing water, the washing water supply circuit 5 is located outside the absorption tower body 11, and the two ends of the washing water supply circuit 5 are respectively a liquid inlet end and a liquid supply end, the liquid inlet end of the washing water supply circuit 5 is connected with the second liquid collector 43, the liquid supply end is connected with the third liquid distributor 41, and the washing water supply circuit 5 is provided with a tertiary feed pump 51 for pumping the washing water in the second liquid collector 43 from the liquid inlet end to the liquid supply end.

[0060] In the embodiment, by arranging the amine recovery unit 4 in the absorption tower 1, the flue gas after decarbonization is cooled by water washing, and the amine substances and water carried in the flue gas are recovered, the amine escape is reduced, and the environmental pollution is reduced. The specific operation is as follows: before starting the device, an appropriate amount of washing water is added in the second liquid collector 43, after starting the device, the tertiary feed pump 51 continuously extracts the washing water from the second liquid collector 43, and the washing water is transported to the third liquid distributor 41 through the washing water supply circuit 5, the washing water is sprayed to the amine recovery layer 42 by the third liquid distributor 41, when the flue gas after secondary absorption enters the amine recovery layer 42, the flue gas reacts with the washing water, the flue gas is cooled, and the amine substances and water carried in the flue gas are recovered, and the flue gas after amine recovery is discharged through the smoke outlet 111 at the top end of the absorption tower body.

[0061] Further, the washing water supply circuit 5 is further provided with a third cooler 52, one end of the third cooler 52 is connected with the third feeding pump 51, and the other end is connected with the liquid supply end of the washing water supply circuit 5. By setting the third cooler 52 to cool the washing water, the washing water can further cool the flue gas, increase the reaction rate of the washing water with the flue gas, and increase the recovery efficiency of the amine and water carried in the flue gas.

[0062] In addition, in order to detect the absorption efficiency of the device to CO2 and the effect of preventing amine escape, the applicant compares the operation effects under different working conditions, and the results are as follows:

[0063] Table 1

[0064]

[0065] As can be seen from Table 1, as the temperature of the pretreated flue gas increases and the CO2 concentration in the flue gas at the flue gas inlet 110 increases, the CO2 absorption rate is always higher than 90%, and the amine concentration in the flue gas at the flue gas outlet 111 is always lower than ppm. In the traditional technology, the CO2 absorption rate is generally about 80% to 90%, and the amine concentration in the flue gas at the flue gas outlet 111 is generally about 10 ppm to 20 ppm. Therefore, compared with the traditional technology, the embodiment of the present application can effectively increase the absorption rate of carbon dioxide and reduce amine escape.

[0066] Further, the carbon dioxide absorption device further comprises a washing water recovery circuit 6, the washing water recovery circuit 6 is located outside the absorption tower body 11, and the two ends of the washing water recovery circuit 6 are respectively a liquid inlet end and a liquid supply end. The liquid inlet end of the washing water recovery circuit 6 is connected with the third cooler 52, and the liquid supply end is connected with the liquid inlet end of the absorption liquid supply circuit 2. By recovering the washing water after reacting with the flue gas, the amine components in the recovered washing water can supplement the absorption liquid.

[0067] Further, the carbon dioxide absorption device further comprises a plurality of component monitoring devices 7, and the plurality of component monitoring devices 7 are respectively arranged at the liquid inlet end of the absorption liquid supply circuit 2 and the liquid inlet end of the washing water supply circuit 5. The plurality of component monitoring devices 7 are respectively used for monitoring the water and amine component contents of the absorption liquid and the washing water on the absorption liquid supply circuit 2 and the washing water supply circuit 5.

[0068] In the embodiment, the application further provides a water replenisher 24 and an amine replenisher 25 at the liquid storage tank 23 to replenish water and amine components of the absorption liquid in the liquid storage tank 23, and a water replenisher 24 connected to the second liquid collector 43 to replenish water of the second liquid collector 43. When the component monitoring device 7 monitors that the components (water and amine components) of the absorption liquid entering the liquid inlet end of the absorption liquid supply circuit 2 or the water entering the liquid inlet end of the water supply circuit 5 are insufficient, the controller controls the corresponding water replenisher 24 and amine replenisher 25 to replenish the components, so as to ensure the effect of the absorption liquid and the water.

[0069] Further, the carbon dioxide absorption device further comprises a desorption tower 8, an absorption liquid desorption circuit 9, an absorption liquid recovery circuit 10,

[0070] The desorption tower 8 comprises a desorption tower body 80 and a desorption unit, the top end of the desorption tower body 80 is provided with a gas outlet 85, the bottom end of the desorption tower body 80 is provided with a liquid outlet, and the desorption unit is arranged in the desorption tower body 80;

[0071] The desorption unit comprises a fourth liquid distributor 81, a two-stage filler layer 82, a one-stage filler layer 83 and a third liquid collector 84 arranged in sequence and spaced apart from top to bottom, the absorption liquid desorption circuit 9 and the absorption liquid recovery circuit 10 are respectively arranged outside the desorption tower body 80, and the two ends of the absorption liquid desorption circuit 9 and the absorption liquid recovery circuit 10 are respectively a liquid inlet end and a liquid supply end, the liquid inlet end of the absorption liquid desorption circuit 9 is connected to the bottom of the absorption tower body 11, the liquid supply end is connected to the fourth liquid distributor 81, the absorption liquid desorption circuit 9 is provided with a four-stage feed pump 91 for pumping the absorption liquid at the bottom of the absorption tower body 11 from the liquid inlet end to the fourth liquid distributor 81, the liquid inlet end of the absorption liquid recovery circuit 10 is connected to the bottom of the desorption tower body 80, the liquid supply end is connected to the liquid inlet end of the absorption liquid supply circuit 2, and the absorption liquid recovery circuit 10 is provided with a five-stage feed pump 101 for pumping the absorption liquid at the bottom of the desorption tower body 80 from the bottom of the desorption tower body 80 to the liquid inlet end of the absorption liquid supply circuit 2.

[0072] In the present embodiment, the desorption unit further comprises a reboiler 86 connected between the third liquid collector 84 and the bottom of the desorption tower body 80. The "rich liquid" with high CO2 concentration falling into the bottom of the absorption tower body 11 is pumped out from the bottom of the absorption tower body 11 by a fourth feed pump 91 and transported into the desorption tower body 80 through the absorption liquid desorption circuit 9. The "rich liquid" is sprayed through the fourth liquid distributor 81 and sequentially enters the second-stage packing layer 82 and the first-stage packing layer 83, and finally falls into the third liquid collector 84, and then flows into the reboiler 86 and is heated to a certain temperature. After heating, the CO2 in the "rich liquid" is separated out, and the separated CO2 forms bubbles and gradually rises. The "rich liquid" entering the absorption tower body 11 subsequently exchanges heat with the "rich liquid" in the first-stage packing layer 83 and the second-stage packing layer 82, until the separated CO2 rises to the top of the desorption tower body 80. By providing a gas-liquid separation device at the top of the desorption tower body 80, the CO2 can be separated from the liquid droplets of the small amount of absorbent that may be carried, and relatively pure CO2 is obtained. The separated CO2 can be used for subsequent compression, storage or utilization processes. The "rich liquid" from which the CO2 is separated becomes "lean liquid", which is pumped out from the bottom of the desorption tower body 80 by a fifth feed pump 101 and transported into the liquid storage tank 23 through the absorption liquid recovery circuit 10, so as to complete the recovery and utilization of the absorption liquid and reduce the loss of the absorption liquid.

[0073] Further, the absorption liquid desorption circuit 9 is further provided with a heat exchanger 92, which is arranged between the fourth feed pump 91 and the fourth liquid distributor 81, and one end of the heat exchanger 92 is connected with the liquid supply end of the absorption liquid desorption circuit 9, and the other end is connected with the liquid inlet end of the absorption liquid recovery circuit 10. The heat exchanger 92 can exchange heat between the "rich liquid" pumped out from the bottom of the absorption tower body 11 by the fourth feed pump 91 and the "lean liquid" pumped out from the bottom of the desorption tower body 80 by the fifth feed pump 101, so as to increase the temperature of the "rich liquid" entering the desorption tower body 80 and reduce the temperature of the "lean liquid" entering the liquid storage tank 23.

[0074] The application also provides a carbon dioxide absorption method using the carbon dioxide absorption device described above, comprising: the controller controls the start of the primary feed pump 31, the secondary feed pump 21, the positive electrode plate 121, the ultrasonic atomizer 131 and the high-voltage electrostatic generator 132, controls the primary feed pump 31 to transport the absorption liquid from the liquid inlet end of the absorption liquid supply circuit 2 to the liquid supply end of the absorption liquid supply circuit 2, controls the ultrasonic atomizer 131 to atomize the absorption liquid, controls the high-voltage electrostatic generator 132 to negatively charge the atomized absorption liquid, controls the positive electrode plate 121 to make the negatively charged absorption liquid fall to the liquid inlet end of the primary absorption liquid circulation circuit 3, and controls the secondary feed pump 21 to transport the absorption liquid from the liquid inlet end of the primary absorption liquid circulation circuit 3 to the liquid supply end of the primary absorption liquid circulation circuit 3. The method can absorb the pretreated flue gas twice, and the atomized absorption liquid can better absorb the flue gas, effectively improve the absorption efficiency of CO2 in the flue gas, reduce the reaction time with the flue gas, and effectively prevent amine escape after the absorption liquid reacts with the flue gas.

[0075] In summary, the carbon dioxide absorption device and method provided by the embodiment can effectively increase the gas-liquid contact area and enhance the mass transfer efficiency, realize the staged absorption of carbon dioxide to improve the absorption efficiency, recover the amine components, degradation products and water in the decarbonized flue gas through water washing, effectively reduce amine escape, avoid pollution to the environment, form a closed circulation system for the device as a whole, and effectively reduce the land occupation area and operation complexity of the equipment.

[0076] This specification discloses the application with reference to the accompanying drawings, and also enables those skilled in the art to implement the application, including manufacturing and using any device or system, using appropriate materials, and using any combined method. The scope of the application is defined by the claimed technical solutions, and includes other examples thought by those skilled in the art. As long as such other examples include structural elements not different from the literal language of the claimed technical solutions, or such other examples contain equivalent structural elements not substantially different from the literal language of the claimed technical solutions, such other examples should be considered to be within the protection scope determined by the claimed technical solutions of the application.

Claims

1. A carbon dioxide absorption device, characterized in that, The application relates to a flue gas absorption device. The absorption tower comprises an absorption tower body, a first-stage absorption unit and a second-stage absorption unit, the bottom end of the absorption tower body is provided with a flue gas inlet, the top end of the absorption tower body is provided with a flue gas outlet, and the second-stage absorption unit and the first-stage absorption unit are sequentially arranged in the absorption tower body from top to bottom. The second-stage absorption unit comprises a second liquid distributor, an ultrasonic atomizer, a high-voltage static electricity generator and a second-stage absorption layer which are sequentially and spacedly arranged from top to bottom. The first-stage absorption unit comprises a first liquid collector, a positively-charged electrode plate, a first liquid distributor and a first-stage absorption layer which are sequentially and spacedly arranged from top to bottom. The controller is electrically connected with the ultrasonic atomizer, the high-voltage static electricity generator, the positively-charged electrode plate, the first-stage feeding pump and the second-stage feeding pump. The application further relates to a desorption tower, an absorption liquid desorption circuit and an absorption liquid recovery circuit. The desorption tower comprises a desorption tower body and a desorption unit, the top end of the desorption tower body is provided with a gas outlet, and the bottom end of the desorption tower body is provided with a liquid outlet. The desorption unit comprises a fourth liquid distributor, a second-stage filler layer, a first-stage filler layer and a third liquid collector which are sequentially and spacedly arranged from top to bottom. The absorption liquid desorption circuit and the absorption liquid recovery circuit are located outside the desorption tower body, and the two ends of the absorption liquid desorption circuit and the absorption liquid recovery circuit are respectively an inlet end and a liquid supply end. The inlet end of the absorption liquid desorption circuit is connected with the bottom of the absorption tower body, the liquid supply end of the absorption liquid desorption circuit is connected with the fourth liquid distributor, a fourth-stage feeding pump is arranged on the absorption liquid desorption circuit and used for pumping the absorption liquid from the inlet end to the fourth liquid distributor. The inlet end of the absorption liquid recovery circuit is connected with the bottom of the desorption tower body, the liquid supply end of the absorption liquid recovery circuit is connected with the inlet end of the absorption liquid supply circuit, a fifth-stage feeding pump is arranged on the absorption liquid recovery circuit and used for pumping the absorption liquid from the bottom of the desorption tower body to the inlet end of the absorption liquid supply circuit.

2. The carbon dioxide absorbing apparatus according to claim 1, wherein The absorption liquid supply circuit is further provided with a secondary cooler, one end of the secondary cooler is connected with the secondary feed pump, and the other end is connected with the liquid supply end of the absorption liquid supply circuit.

3. The carbon dioxide absorbing apparatus according to claim 1, wherein The primary absorption liquid circulation circuit is further provided with a primary cooler, one end of the primary cooler is connected with the primary feed pump, and the other end is connected with the liquid supply end of the primary absorption liquid circulation circuit.

4. The carbon dioxide absorbing apparatus according to claim 1, wherein The washing water supply circuit is further provided with a third liquid distributor, a washing water recovery layer and a second liquid collector arranged in sequence from top to bottom, the second liquid collector is used for storing washing water, the washing water supply circuit is located outside the absorption tower body, and two ends of the washing water supply circuit are respectively a liquid inlet end and a liquid supply end, the liquid inlet end of the washing water supply circuit is connected with the second liquid collector, the liquid supply end of the washing water supply circuit is connected with the third liquid distributor, and a third feed pump is arranged on the washing water supply circuit and used for pumping the washing water in the second liquid collector from the liquid inlet end to the liquid supply end. The washing water supply circuit is further provided with a third cooler, one end of the third cooler is connected with the third feed pump, and the other end is connected with the liquid supply end of the washing water supply circuit.

5. The carbon dioxide absorbing apparatus according to claim 4, wherein The washing water recovery circuit is located outside the absorption tower body, and two ends of the washing water recovery circuit are respectively a liquid inlet end and a liquid supply end, the liquid inlet end of the washing water recovery circuit is connected with the third cooler, and the liquid supply end of the washing water recovery circuit is connected with the liquid inlet end of the absorption liquid supply circuit.

6. The carbon dioxide absorbing apparatus according to claim 5, wherein The absorption liquid supply circuit is further provided with a secondary cooler, one end of the secondary cooler is connected with the secondary feed pump, and the other end is connected with the liquid supply end of the absorption liquid supply circuit.

7. The carbon dioxide absorbing apparatus according to claim 6, wherein The absorption liquid desorption circuit is further provided with a heat exchanger, the heat exchanger is arranged between the fourth feed pump and the fourth liquid distributor, one end of the heat exchanger is connected with the liquid supply end of the absorption liquid desorption circuit, and the other end is connected with the liquid inlet end of the absorption liquid recovery circuit.

8. The carbon dioxide absorbing apparatus according to claim 1, wherein The carbon dioxide absorption device comprises:

9. A method of absorbing carbon dioxide, characterized by, The controller controls the primary feed pump, the secondary feed pump, the positive electrode plate, the ultrasonic atomizer and the high-voltage electrostatic generator to be started, controls the secondary feed pump to transport the absorption liquid from the liquid inlet end of the absorption liquid supply circuit to the liquid supply end of the absorption liquid supply circuit, controls the ultrasonic atomizer to atomize the absorption liquid, controls the high-voltage electrostatic generator to charge the atomized absorption liquid with negative electricity, controls the positive electrode plate to make the absorption liquid with negative electricity fall to the liquid inlet end of the primary absorption liquid circulation circuit, and controls the primary feed pump to transport the absorption liquid from the liquid inlet end of the primary absorption liquid circulation circuit to the liquid supply end of the primary absorption liquid circulation circuit. ​

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