Co2 capture device and method thereof, method for regenerating adsorbent

Abstract

The present application relates to the technical field of flue gas CO2 removal, in particular to a CO2 capture device and method, and a method for regenerating adsorbent. The present application adopts an adsorption device comprising (N-1) original flue gas auxiliary feeding ports, N adsorbent beds, N support pipes and (N-1) auxiliary CO2 online analyzers, and specific adsorbent, thereby significantly improving the processing capacity of original flue gas and the working efficiency of the CO2 capture device by reducing the pressure drop in the adsorption device, and large-scale CO2 capture can be achieved. By limiting the feeding CO2 online analyzer, the discharging CO2 online analyzer and the auxiliary CO2 online analyzer in the adsorption device, the present application can timely reflect the adsorption state of the adsorbent in each adsorption bed by monitoring the CO2 content in the original flue gas and the clean flue gas, and the CO2 content in the flue gas after passing through the Nth adsorbent bed, so as to real-time regulate the flow of the original flue gas auxiliary feeding port.

Description

Technical Field

[0001] This invention relates to the field of flue gas CO2 removal technology, specifically to a CO2 capture device and method, and a method for adsorbent regeneration. Background Technology

[0002] The capture and separation of CO2 in flue gas is a research hotspot of widespread interest worldwide, with various new technologies constantly being proposed and developed. Currently, the main methods for capturing and separating CO2 include liquid solvent absorption, adsorption, biological methods, membrane separation, and cryogenic freezing. Adsorption is a good emission reduction technology due to its low energy consumption, low pollution, and ease of automation.

[0003] CN107485960A discloses an apparatus and method for removing CO2 from flue gas using an amine-based solid adsorbent. This method involves loading a solid adsorbent into an adsorption bed to adsorb CO2 from the flue gas, and then regenerating the adsorbent using vacuum regeneration, thermal regeneration, or a combination of both. The adsorption and regeneration of CO2 in the flue gas are carried out in the same reactor. However, the adsorption device involved in this method is a traditional fixed-bed system, which experiences a significant pressure drop during CO2 adsorption, severely limiting its application in large-scale CO2 capture.

[0004] CN108339371A discloses an apparatus and method for continuous CO2 adsorption. The adsorption system includes an adsorption device, a sieve, a lift, and a gas-liquid separator. The adsorption device, including a moving bed adsorber, mainly comprises an adsorption section, a desorption section, and a cooling section. While this method achieves continuous CO2 adsorption, it places higher demands on the adsorbent, requiring it to have a low density. Furthermore, due to the influence of the adsorbent's own gravity, it is difficult to use this device for large-scale CO2 capture.

[0005] Therefore, existing technologies are constrained by both adsorbents and adsorption devices, making it difficult to achieve large-scale CO2 capture. There is an urgent need for a device and method for large-scale CO2 capture. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem that large-scale CO2 capture is difficult due to high pressure drop and low adsorbent density in the existing adsorption method. This invention provides a CO2 capture device and method, as well as a method for adsorbent regeneration. The capture device can effectively reduce the pressure drop of the adsorption device, significantly increase the flux of the original flue gas, and achieve large-scale CO2 capture.

[0007] To achieve the above objectives, the first aspect of the present invention provides a CO2 capture device, comprising: a feed pipeline, an adsorption device, and a discharge pipeline connected in sequence; a feed CO2 online analyzer and a discharge CO2 online analyzer are respectively installed on the feed pipeline and the discharge pipeline; the adsorption device has N adsorbent beds and N support tubes inside, and the support tubes are installed at the bottom of the adsorbent beds; the shell of the adsorption device has (N-1) auxiliary feed ports for raw flue gas and (N-1) auxiliary CO2 online analyzers, and the auxiliary feed ports for raw flue gas and the auxiliary CO2 online analyzers are installed between two adjacent adsorbent beds; The adsorbent bed is filled with adsorbent, and the adsorbent is a honeycomb adsorbent; The adsorption device is used to adsorb CO2 in the raw flue gas and the adsorbent in the adsorbent bed to obtain clean flue gas; the feed CO2 online analyzer and the discharge CO2 online analyzer are used to monitor the CO2 content in the raw flue gas and the clean flue gas, respectively. The (N-1)th auxiliary online CO2 analyzer is used to monitor the CO2 content in the flue gas after the original flue gas passes through the (N-1)th adsorbent bed; The flow rate of the raw flue gas in the (N-1)th raw flue gas auxiliary feed port depends on the CO2 content in the (N-1)th auxiliary CO2 online analyzer; Where N is a positive integer and N≥2.

[0008] A second aspect of the present invention provides a CO2 capture method, the method comprising: passing the raw flue gas from top to bottom or from bottom to top through the device provided in the first aspect, such that the adsorbent packed in the adsorbent bed of the adsorption device adsorbs the CO2 in the raw flue gas to obtain clean flue gas; Wherein, the CO2 content in the clean flue gas is ≤ the CO2 concentration in the flue gas after passing through the Nth adsorbent bed is ≤ the CO2 content in the original flue gas.

[0009] A third aspect of the present invention provides a method for regenerating an adsorbent, which is carried out in the apparatus provided in the first aspect, wherein when the adsorption apparatus is in a shutdown state, the adsorbent packed in the adsorption apparatus in the shutdown state is desorbed and regenerated.

[0010] Through the above technical solution, this invention employs an adsorption device comprising (N-1) auxiliary feed inlets for raw flue gas, N adsorbent beds, N support tubes, and (N-1) auxiliary online CO2 analyzers, along with a specific adsorbent. By reducing the pressure drop within the adsorption device, it significantly improves the processing capacity of the raw flue gas and the working efficiency of the CO2 capture device, enabling large-scale CO2 capture. Simultaneously, the adsorption device provided by this invention contains up to N support tubes, which, through heat transfer, enable the desorption and regeneration of the adsorbent adsorbing CO2 in the adsorbent beds, achieving long-term stable operation of the CO2 capture device, simplifying the device, and reducing production costs. Furthermore, the feed CO2 online analyzer, discharge CO2 online analyzer, and auxiliary CO2 online analyzer in the adsorption device provided by this invention, by monitoring the CO2 content in the raw and clean flue gas, as well as the CO2 content in the flue gas after passing through the Nth adsorbent bed, can promptly reflect the adsorption state of the adsorbent in each adsorption bed, determine whether the adsorbent is saturated, and thus adjust the flow rate of the auxiliary feed inlets for raw flue gas in real time. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a CO2 capture device provided by the present invention.

[0012] Explanation of reference numerals in the attached figures Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] In this invention, the terms "first," "second," "(N-1)," and "Nth" do not represent a sequential order, nor do they limit the various materials or components; they are merely used to distinguish between them. For example, "first" and "second" in "first CO2-assisted online analyzer" and "second CO2-assisted online analyzer" are only used to distinguish that they are not the same CO2-assisted online analyzer.

[0015] The first aspect of the present invention provides a CO2 capture device, comprising: a feed pipeline, an adsorption device, and a discharge pipeline connected in sequence; a feed CO2 online analyzer and a discharge CO2 online analyzer are respectively installed on the feed pipeline and the discharge pipeline; the adsorption device has N adsorbent beds and N support tubes inside, and the support tubes are installed at the bottom of the adsorbent beds; the shell of the adsorption device has (N-1) raw flue gas auxiliary feed ports and (N-1) auxiliary CO2 online analyzers, and the raw flue gas auxiliary feed ports and auxiliary CO2 online analyzers are installed between two adjacent adsorbent beds; The adsorbent bed is filled with adsorbent, and the adsorbent is a honeycomb adsorbent; The adsorption device is used to adsorb CO2 in the raw flue gas and the adsorbent in the adsorbent bed to obtain clean flue gas; the feed CO2 online analyzer and the discharge CO2 online analyzer are used to monitor the CO2 content in the raw flue gas and the clean flue gas, respectively. The (N-1)th auxiliary online CO2 analyzer is used to monitor the CO2 content in the flue gas after the original flue gas passes through the (N-1)th adsorbent bed; The flow rate of the raw flue gas in the (N-1)th raw flue gas auxiliary feed port depends on the CO2 content in the (N-1)th auxiliary CO2 online analyzer; Where N is a positive integer and N≥2.

[0016] The inventors of this invention have discovered that by employing an adsorption device comprising at least one support tube and at least one adsorbent bed, and an adsorbent with a specific structure, the adsorption capacity of the adsorbent in the adsorption device can be increased by reducing the pressure drop of the adsorption device, thereby achieving large-scale CO2 capture. Simultaneously, the CO2 capture device provided by this invention also includes an online CO2 analyzer, which can effectively determine the operating status of the adsorption device. Combined with at least one support tube, it enables online regeneration of the adsorbent in the adsorbent bed of the adsorption device, thus improving the operating cycle of the CO2 capture device.

[0017] In this invention, unless otherwise specified, the raw flue gas is flue gas from a coal-fired power plant. Preferably, the raw flue gas mainly contains CO2, N2, O2, and H2O, and also contains trace amounts of SO2. x NO x .

[0018] In some embodiments of the present invention, preferably, the ratio of the height of the adsorbent bed to the diameter of the support tube is 5-20:1, for example, 5:1, 8:1, 10:1, 12:1, 15:1, 20:1, and any value within the range of any two values, preferably 8-15:1. Here, the ratio of the height of the adsorbent bed to the diameter of the support tube refers to the ratio of the height of any one adsorbent bed to the diameter of any one support tube. Using the preferred conditions is more conducive to improving the regeneration effect of the adsorbent in the adsorbent bed.

[0019] In some embodiments of the present invention, preferably, the height ratio of the adsorbent bed to the adsorption device is 0.5-0.9:1, for example, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, and any value within the range of any two values, preferably 0.6-0.8:1. Here, the height ratio of the adsorbent bed to the adsorption device refers to the ratio of the total height of at least one adsorbent bed to the height of the adsorption device. Using these preferred conditions, while ensuring the flue gas treatment throughput, it is more conducive to improving the utilization rate of the bed adsorbent.

[0020] In some embodiments of the present invention, preferably, the number of adsorbent beds is ≥1, and more preferably 2-10.

[0021] In this invention, the adsorbent bed is used to perform an adsorption reaction with CO2 in the raw flue gas introduced into the adsorption device, and the adsorbent bed contains adsorbent.

[0022] In this invention, to further increase the CO2 adsorption capacity of the adsorbent, preferably, the bulk density of the adsorbent is ≤0.7 g / cm³. 3 Preferably, it is 0.45-0.65 g / cm³. 3 In this invention, when the bulk density of the adsorbent is > 0.7 g / cm³ 3 The pressure drop of the adsorbent bed is >2000 Pa.

[0023] In this invention, a wide range of types of adsorbents can be selected, as long as the bulk density of the adsorbent is ≤0.7 g / cm³. 3 That is, the adsorbent is selected from at least one of carbon-based honeycomb adsorbents, amino-based honeycomb adsorbents, molecular sieve-based honeycomb adsorbents, and metal oxide-based honeycomb adsorbents.

[0024] In some embodiments of the present invention, preferably, the carbon-based honeycomb adsorbent is selected from porous honeycomb activated carbon, including but not limited to coal-based honeycomb activated carbon and wood-based honeycomb activated carbon.

[0025] In some embodiments of the present invention, preferably, the molecular sieve-based honeycomb adsorbent is selected from at least one of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve and 13X molecular sieve.

[0026] In some embodiments of the present invention, preferably, the metal oxide-based honeycomb adsorbent is selected from alumina honeycomb adsorbents and / or metal-organic framework honeycomb adsorbents (MOFs).

[0027] In some embodiments of the present invention, preferably, the amino honeycomb adsorbent is selected from porous honeycomb solid organic amines, including but not limited to ethanolamine, diethanolamine, triethylenetetramine, tetraethylenepentamine, and polyethyleneimine.

[0028] In this invention, the arrangement of the support tube and adsorbent bed is not required, as long as the adsorption device contains at least one support tube and at least one adsorbent bed. The arrangement of the support tube and adsorbent bed can be: one support tube - one adsorbent bed - one support tube - one adsorbent bed... stacked alternately; or one support tube - at least one adsorbent bed - at least one support tube - one adsorbent bed... stacked alternately; or, at least one support tube is vertically inserted in the middle of at least one adsorbent bed, or at least one support tube is vertically distributed around at least one adsorbent bed.

[0029] In some embodiments of the present invention, preferably, the support tube and the adsorbent bed are stacked alternately.

[0030] In this invention, the adsorption device contains at least one support tube, which can be used to support the adsorbent bed, increase the amount of CO2 adsorbed in the adsorbent bed by cooling, and regenerate the adsorbent adsorbing CO2 in the adsorbent bed online by heating.

[0031] In some embodiments of the present invention, preferably, the arrangement density of the support tubes is 0.1-1, for example, 0.1, 0.2, 0.3, 0.5, 0.6, 0.8, 1, and any value within the range of any two values, preferably 0.2-0.6. The arrangement density described in the present invention refers to the density equivalent to 1 m... 2 The cross-sectional area of ​​the support tubes is such that the arrangement density of the support tubes is 0.1-1 m². 2 Preferably, it is 0.2-0.6 m. 2 .

[0032] In one specific embodiment of the present invention, preferably, the support tube is used to cool the adsorbent bed, thereby enhancing the adsorption of CO2 by the adsorbent in the adsorbent bed.

[0033] In one specific embodiment of the present invention, preferably, the support tube is used to heat the adsorbent bed, so that the adsorbent adsorbing CO2 in the adsorbent bed can be regenerated / desorbed online.

[0034] In this invention, preferably, the heating method of the support tube is selected from heat exchange medium heat exchange and / or thermocouple heating.

[0035] In some embodiments of the present invention, preferably, the adsorption device is an axisymmetric reactor, wherein the axisymmetric reactor includes, but is not limited to, an axially fixed-bed reactor.

[0036] In this invention, the specifications of the adsorption device have a wide range of options, and the specifications of the adsorption device depend on the amount of raw flue gas to be processed.

[0037] In some embodiments of the present invention, preferably, the feed CO2 online analyzer and the discharge CO2 online analyzer are used to monitor the CO2 content in the raw flue gas and the clean flue gas, respectively; the (N-1)th auxiliary CO2 online analyzer is used to monitor the CO2 content in the flue gas after the raw flue gas passes through the (N-1)th adsorbent bed.

[0038] In this invention, a wide range of types of feed CO2 online analyzers, discharge CO2 online analyzers, and auxiliary CO2 online analyzers can be selected. As long as the feed CO2 online analyzers, discharge CO2 online analyzers, and auxiliary CO2 online analyzers can monitor the CO2 content in the raw flue gas and the clean flue gas, as well as the CO2 content in the flue gas after passing through the adsorbent bed, they are acceptable.

[0039] In this invention, preferably, the adsorption device further includes a gas distributor, which is disposed at the gas inlet of the adsorption device for distributing the raw flue gas. The raw flue gas passing through the gas distributor can be evenly distributed into the adsorbent bed, preventing uneven airflow distribution and allowing the raw flue gas to pass through the adsorbent bed in an approximately plug flow manner, effectively improving the utilization rate of the adsorbent.

[0040] In this invention, a wide range of types of gas distributors can be selected. Preferably, the gas distributor is selected from conventional low-pressure-drop lateral gas distributors or bottom-opening gas distributors. Further details of this invention are omitted here.

[0041] In this invention, the arrangement of the gas distributor in the adsorption device depends on the inlet direction of the original flue gas.

[0042] In one embodiment of the present invention, preferably, when the original flue gas enters from the bottom and exits from the top, the gas distributor is disposed at the bottom of the adsorption device.

[0043] In one embodiment of the present invention, preferably, when the raw flue gas enters from the top and exits from the bottom, the gas distributor is disposed at the top of the adsorption device.

[0044] A preferred embodiment of the present invention, such as Figure 1 As shown, the CO2 capture device includes: a feed pipeline, an adsorption device 11, and a discharge pipeline connected in sequence; a feed CO2 online analyzer 7 and a discharge CO2 online analyzer 8 are respectively installed on the feed pipeline and the discharge pipeline; the adsorption device 11 is internally provided with N adsorbent beds 3 and N support tubes 5, and a support tube 5 is provided at the bottom of the adsorbent bed 3; the shell of the adsorption device 11 is provided with (N-1) raw flue gas auxiliary feed ports 10 and (N-1) auxiliary CO2 online analyzers 9, and a raw flue gas auxiliary feed port 10 and an auxiliary CO2 online analyzer 9 are provided between two adjacent adsorbent beds 3; the adsorbent beds 3 are filled with The adsorbent is a honeycomb adsorbent; the adsorption device 11 is used to adsorb CO2 in the raw flue gas 1 and the adsorbent in the adsorbent bed 3 to obtain clean flue gas 2; the feed CO2 online analyzer 7 and the discharge CO2 online analyzer 8 are used to monitor the CO2 content in the raw flue gas 1 and the clean flue gas 2, respectively; the (N-1)th auxiliary CO2 online analyzer is used to monitor the CO2 content in the flue gas after the raw flue gas passes through the (N-1)th adsorbent bed; the flow rate of the raw flue gas in the (N-1)th raw flue gas auxiliary feed port depends on the CO2 content in the (N-1)th auxiliary CO2 online analyzer; where N is a positive integer and N≥2; When the raw flue gas 1 enters from the bottom and exits from the top, the gas distributor 6 is located at the bottom of the adsorption device 11 to distribute the raw flue gas 1.

[0045] A second aspect of the present invention provides a CO2 capture method, the method comprising: passing the raw flue gas from top to bottom or from bottom to top through the device provided in the first aspect, such that the adsorbent packed in the adsorbent bed of the adsorption device adsorbs the CO2 in the raw flue gas to obtain clean flue gas; Wherein, the CO2 concentration in the clean flue gas is ≤ the CO2 concentration in the flue gas after passing through the Nth adsorbent bed is ≤ the CO2 concentration in the original flue gas.

[0046] In this invention, the airflow of the raw flue gas into the adsorption device can be either top-in, bottom-out or bottom-in, top-out, with bottom-in, top-out being preferred. This preferred method is more conducive to the contact between the flue gas and the adsorbent, promoting the adsorption of the flue gas by the adsorbent.

[0047] In this invention, the flow rate of the raw flue gas in the (N-1)th auxiliary raw flue gas inlet depends on the CO2 content in the (N-1)th auxiliary online CO2 analyzer.

[0048] In some embodiments of the present invention, preferably, when When the flow rate is 80%, maintain the flow rate of the (N-1)th raw flue gas auxiliary feed inlet.

[0049] In some embodiments of the present invention, preferably, when When the flow rate is greater than 80%, increase the flow rate of the (N-1)th raw flue gas auxiliary feed inlet.

[0050] In some embodiments of the present invention, preferably, the CO2 concentration in the original flue gas is ≤20% by volume, and more preferably 8-16% by volume.

[0051] In some embodiments of the present invention, preferably, the temperature of the original flue gas is ≤45℃, and more preferably 20-40℃.

[0052] In some embodiments of the present invention, preferably, the adsorption conditions include: space velocity ≤ 5000 m. 3 / (m 3 (·h), preferably 1000-3500 m 3 / (m 3 • h); pressure ≤ 10 kPa, preferably 3-8 kPa; time ≤ 30 min, preferably 5-25 min.

[0053] In some embodiments of the present invention, preferably, the pressure drop of the raw flue gas through the adsorbent bed is ≤2000 Pa, more preferably 500-1500 Pa, and the linear velocity is ≤1 m / s, more preferably 0.1-0.5 m / s.

[0054] In this invention, passing the raw flue gas through the CO2 capture device from top to bottom or bottom to top can effectively increase the amount of CO2 adsorbed in the raw flue gas and extend the service life of the adsorbent.

[0055] According to the present invention, preferably, the method further includes: cooling the N support tubes in the device by introducing a cooling medium to cool them, thereby facilitating the adsorption of the adsorbent in the adsorbent bed. This arrangement is more conducive to enhancing the adsorption rate of the adsorbent in the adsorbent bed.

[0056] In some embodiments of the present invention, preferably, the flow rate of the cooling medium is 0.1-2 m / s, more preferably 0.1-1 m / s; and the temperature is 5-30°C, more preferably 10-20°C. Using these preferred conditions is more conducive to improving the adsorption rate of the adsorbent.

[0057] A third aspect of the present invention provides a method for regenerating an adsorbent, which is carried out in the apparatus provided in the first aspect, wherein when the adsorption apparatus is in a shutdown state, the adsorbent packed in the adsorption apparatus in the shutdown state is desorbed and regenerated.

[0058] Using the method provided by this invention, the desorption rate of the adsorbent was measured to be 75-95%, that is, the regeneration rate of the adsorbent was 75-95%.

[0059] In this invention, unless otherwise specified, the shutdown state refers to a state where the CO2 concentration in the clean flue gas is close to the CO2 concentration in the original flue gas. Preferably, ≥95% indicates that the adsorption device is in a shutdown state.

[0060] In a preferred embodiment of the present invention, the raw flue gas is distributed into the adsorbent bed of the adsorption device via a gas distributor, and after adsorption, it enters the subsequent process. As the operating time of the adsorbent in the adsorption device increases, the adsorbent may experience a decrease in activity or even deactivation. According to the process adsorption rate requirements, the device is shut down and restarted by stopping the flow of raw flue gas and introducing a heat exchange medium into the support tube to regenerate the adsorbent through heat exchange.

[0061] In some embodiments of the present invention, preferably, the method includes the following steps: (1) Stop the feeding and discharging of the adsorption device; (2) Heat exchange medium is introduced into N support tubes in the adsorption device that is in a shutdown state to exchange heat, so that the adsorbent in the adsorbent bed is desorbed.

[0062] In this invention, the desorption conditions have a wide range of selection; as long as the adsorbed CO2 in the adsorbent is released / desorbed by heating, it is sufficient. Preferably, the desorption conditions include: a temperature of 60-300℃, more preferably 80-150℃; a pressure of atmospheric pressure; and a time of 5-60 min, more preferably 10-30 min.

[0063] In some embodiments of the present invention, preferably, the inlet temperature of the heat exchange medium is 100-350°C, more preferably 100-250°C; and the outlet temperature of the heat exchange medium is 80-200°C, more preferably 80-150°C.

[0064] In some embodiments of the present invention, preferably, the heat exchange medium is selected from at least one of high-temperature flue gas from power plants, auxiliary heat from power plants, and thermocouples.

[0065] The present invention will be described in detail below through embodiments.

[0066] In this invention, unless otherwise specified, the adsorption capacity refers to the percentage of CO2 adsorbed per unit mass of adsorbent at 40°C and a CO2 concentration of 15% by volume.

[0067] Example 1 (1) CO 2 Schematic diagram of the trapping device ,like Figure 1 As shown, the device includes: a feed CO2 online analyzer 7, an adsorption device 11, and an outlet CO2 online analyzer 8 connected in sequence. The adsorption device 11 has four support tubes 5 and four adsorbent beds 3 internally, with the support tubes 5 and adsorbent beds 3 stacked alternately, and the support tubes 5 are located at the bottom of the adsorbent beds 3. The shell of the adsorption device 11 has three auxiliary raw flue gas inlets 10 and three auxiliary CO2 online analyzers 9. The adsorption device 11 is used to adsorb CO2 from the raw flue gas 1 and adsorbent 4 from the adsorbent beds 3 to obtain clean flue gas 2. A gas distributor 6 is located at the bottom of the adsorption device 11 to distribute the raw flue gas 1. The adsorbent beds 3 are filled with adsorbent 4, and the adsorbent 4 is a honeycomb adsorbent. The height ratio of each adsorbent bed 3 to the diameter of the support tube 5 is 10:1; the height ratio of the four adsorbent beds 3 to the adsorption device 11 is 0.8:1; the arrangement density of the support tubes 5 is 0.4; the adsorbent 4 is porous honeycomb activated carbon (bulk density of 0.6 g / cm³). 3 ).

[0068] (2) CO 2 Capture methods The raw flue gas (temperature 40℃, CO2 concentration 15% by volume) is passed from bottom to top through the aforementioned device, allowing the adsorbent 4 in the adsorbent bed 3 of the adsorption device 11 to adsorb CO2 from the raw flue gas 1. When (CO2 concentration in the raw flue gas - CO2 concentration in the flue gas after passing through the first adsorbent bed) / CO2 concentration in the raw flue gas = 85%, the flow rate of the first auxiliary feed inlet of the raw flue gas is increased; when (CO2 concentration in the raw flue gas - CO2 concentration in the flue gas after passing through the second adsorbent bed) / CO2 concentration in the raw flue gas = 85%, the flow rate of the second auxiliary feed inlet of the raw flue gas is increased; when (CO2 concentration in the raw flue gas - CO2 concentration in the flue gas after passing through the third adsorbent bed) / CO2 concentration in the raw flue gas = 85%, the flow rate of the third auxiliary feed inlet of the raw flue gas is increased, ultimately obtaining clean flue gas 2; wherein the adsorption conditions include: space velocity of 4000 m 3 / (m 3 • h); Pressure: 5 kPa; Time: 30 min; When the CO2 concentration in the clean flue gas 2 reaches 15% by volume, adsorption stops, indicating that adsorption is complete. The pressure drop of the adsorbent bed was measured to be 800 Pa, and the CO2 adsorption capacity of the adsorbent was 3.6 wt%, which is 90% of the saturated adsorption capacity of the adsorbent.

[0069] (3) Methods for regenerating adsorbents Stop the air intake and exhaust of the above-mentioned adsorption device; introduce heat exchange medium into the support tube of the adsorption device in the shutdown state to exchange heat, so that the adsorbent in the adsorbent bed is desorbed; wherein, the desorption conditions include: temperature of 115°C and time of 25 min. The heat exchange medium is high-temperature flue gas; the inlet temperature of the heat exchange medium is 250℃, and the outlet temperature is 130℃. The desorption rate of the adsorbent was measured to be 85%.

[0070] Example 2 (1) CO 2 Schematic diagram of the trapping device ,like Figure 1 As shown, the device includes: a feed CO2 online analyzer 7, an adsorption device 11, and an outlet CO2 online analyzer 8 connected in sequence. The adsorption device 11 has four support tubes 5 and four adsorbent beds 3 internally, with the support tubes 5 and adsorbent beds 3 stacked alternately, and the support tubes 5 are located at the bottom of the adsorbent beds 3. The shell of the adsorption device 11 has three auxiliary raw flue gas inlets 10 and three auxiliary CO2 online analyzers 9. The adsorption device 11 is used to adsorb CO2 in the raw flue gas 1 and adsorbent 4 in the adsorbent beds 3 to obtain clean flue gas 2. A gas distributor 6 is located at the bottom of the adsorption device 11 and is used to distribute the raw flue gas 1. The adsorbent beds 3 are filled with adsorbent 4, and the adsorbent 4 is a honeycomb adsorbent. The height ratio of each adsorbent bed 3 to the diameter of the support tube 5 is 10:1; the height ratio of the four adsorbent beds 3 to the adsorption device 11 is 0.7:1; the arrangement density of the support tubes is 0.6; the adsorbent 4 is porous honeycomb activated carbon (bulk density of 0.5 g / cm³). 3 ).

[0071] (2) CO 2 Capture methodsThe raw flue gas (temperature 40℃, CO2 concentration 15% by volume) is passed from bottom to top through the aforementioned device, allowing the adsorbent 4 in the adsorbent bed 3 of the adsorption device 11 to adsorb CO2 from the raw flue gas 1. When (CO2 concentration in the raw flue gas - CO2 concentration in the flue gas after passing through the first adsorbent bed) / CO2 concentration in the raw flue gas = 80%, the flow rate of the first auxiliary feed inlet of the raw flue gas is maintained; when (CO2 concentration in the raw flue gas - CO2 concentration in the flue gas after passing through the second adsorbent bed) / CO2 concentration in the raw flue gas = 90%, the flow rate of the second auxiliary feed inlet of the raw flue gas is increased; when (CO2 concentration in the raw flue gas - CO2 concentration in the flue gas after passing through the third adsorbent bed) / CO2 concentration in the raw flue gas = 90%, the flow rate of the third auxiliary feed inlet of the raw flue gas is increased, ultimately obtaining clean flue gas 2; wherein the adsorption conditions include: space velocity of 4000 m 3 / (m 3 • h); Pressure: 5 kPa; Time: 30 min; When the CO2 concentration in the clean flue gas 2 reaches 14.9% by volume, adsorption stops, indicating that adsorption is complete. The pressure drop of the adsorbent bed was measured to be 700 Pa, and the CO2 adsorption capacity of the adsorbent was 3.7 wt%, which is 88% of the saturated adsorption capacity of the adsorbent.

[0072] (3) Methods for regenerating adsorbents Stop the air intake and exhaust of the above-mentioned adsorption device; introduce heat exchange medium into the support tube of the adsorption device in the shutdown state to exchange heat, so that the adsorbent in the adsorbent bed can be desorbed; wherein, the desorption conditions include: temperature of 120℃ and time of 20 min. The heat exchange medium is high-temperature flue gas; the inlet temperature of the heat exchange medium is 220℃, and the outlet temperature is 130℃. The desorption rate of the adsorbent was measured to be 90%.

[0073] Example 3 (1) CO 2 Schematic diagram of the trapping device ,like Figure 1 As shown, the device includes: a feed CO2 online analyzer 7, an adsorption device 11, and an outlet CO2 online analyzer 8 connected in sequence. The adsorption device 11 has four support tubes 5 and four adsorbent beds 3 inside, with the support tubes 5 and adsorbent beds 3 stacked at intervals, and the support tubes 5 are located at the bottom of the adsorbent beds 3. The shell of the adsorption device 11 has three raw flue gas auxiliary feed ports 10 and three auxiliary CO2 online analyzers 9. The adsorption device 11 is used to adsorb CO2 in the raw flue gas 1 and adsorbent 4 in the adsorbent beds 3 to obtain clean flue gas 2. A gas distributor 6 is located at the bottom of the adsorption device 11 to distribute the raw flue gas 1. The adsorbent beds 3 are filled with adsorbent 4, and the adsorbent 4 is a honeycomb adsorbent. The height ratio of each adsorbent bed 3 to the diameter of the support tube 5 is 10:1; the height ratio of the four adsorbent beds to the adsorption device is 0.6:1; the arrangement density of the support tubes is 0.25; the adsorbent 4 is porous honeycomb activated carbon (bulk density of 0.6 g / cm³). 3 ).

[0074] (2) CO 2 Capture methods The raw flue gas (temperature 40℃, CO2 concentration 15% by volume) is passed from bottom to top through the aforementioned device, allowing the adsorbent 4 in the adsorbent bed 3 of the adsorption device 11 to adsorb CO2 from the raw flue gas 1. When (CO2 concentration in the raw flue gas - CO2 concentration in the flue gas after the first adsorbent bed) / CO2 concentration in the raw flue gas = 80%, the flow rate of the first auxiliary feed inlet of the raw flue gas is maintained; when (CO2 concentration in the raw flue gas - CO2 concentration in the flue gas after the second adsorbent bed) / CO2 concentration in the raw flue gas = 90%, the flow rate of the second auxiliary feed inlet of the raw flue gas is increased; when (CO2 concentration in the raw flue gas - CO2 concentration after the third adsorbent bed) / CO2 concentration in the raw flue gas = 90%, the flow rate of the third auxiliary feed inlet of the raw flue gas is increased, ultimately obtaining clean flue gas 2. The adsorption conditions include a space velocity of 4000 m / s. 3 / (m 3 • h); Pressure: 5 kPa; Time: 30 min; When the CO2 concentration in the clean flue gas 2 reaches 14% by volume, adsorption stops, indicating that adsorption is complete. The pressure drop of the adsorbent bed was measured to be 800 Pa, and the CO2 adsorption capacity of the adsorbent was 3.5 wt%, which is 87% of the saturated adsorption capacity of the adsorbent.

[0075] (3) Methods for regenerating adsorbents Stop the air intake and exhaust of the above-mentioned adsorption device; introduce heat exchange medium into the support tube of the adsorption device in the shutdown state to exchange heat, so that the adsorbent in the adsorbent bed is desorbed; wherein, the desorption conditions include: temperature of 115°C and time of 15 min. The heat exchange medium is high-temperature flue gas; the inlet temperature of the heat exchange medium is 240℃, and the outlet temperature is 130℃. The desorption rate of the adsorbent was measured to be 91%.

[0076] Example 4 The CO2 capture device provided in Example 1 differs in that the adsorbent is replaced with porous honeycomb activated carbon (bulk density of 0.65 g / cm³). 3 ); According to the CO2 capture method provided in Example 1: the raw flue gas (temperature 40°C, CO2 concentration 12% by volume) is passed from bottom to top through the aforementioned device, so that the adsorbent 4 in the adsorbent bed 3 of the adsorption device 11 adsorbs the CO2 in the raw flue gas 1, resulting in clean flue gas 2; wherein the adsorption conditions include: space velocity of 5000 m 3 / (m 3 • h); Time is 25 min; When the CO2 concentration in the clean flue gas 2 reaches 11.9% by volume, adsorption stops, indicating that adsorption is complete. The pressure drop of the adsorbent bed was measured to be 950 Pa, and the CO2 adsorption capacity of the adsorbent was 3.8 wt%, which is 97% of the saturated adsorption capacity of the adsorbent.

[0077] Following the adsorbent regeneration method provided in Example 1, the desorption rate of the adsorbent was measured to be 88%.

[0078] Example 5 The CO2 capture device provided in Example 1 differs in that the adsorbent is replaced with porous honeycomb activated carbon (bulk density of 0.45 g / cm³). 3 ); According to the CO2 capture method provided in Example 1: the raw flue gas (temperature 40°C, CO2 concentration 13% by volume) is passed from bottom to top through the aforementioned device, so that the adsorbent 4 in the adsorbent bed 3 of the adsorption device 11 adsorbs the CO2 in the raw flue gas 1, resulting in clean flue gas 2; wherein the adsorption conditions include: space velocity of 3000 m / s². 3 / (m 3 • h); Time is 25 min; When the CO2 concentration in the clean flue gas 2 reaches 13% by volume, adsorption stops, indicating that adsorption is complete. The pressure drop of the adsorbent bed was measured to be 500 Pa, and the CO2 adsorption capacity of the adsorbent was 4.2 wt%, which is 95% of the saturated adsorption capacity of the adsorbent.

[0079] Following the adsorbent regeneration method provided in Example 1, the desorption rate of the adsorbent was measured to be 83%.

[0080] Example 6 The CO2 capture device provided in Example 1 differs in that the adsorbent is replaced with a porous honeycomb solid organic amine (bulk density of 0.4 g / cm³). 3 ); According to the CO2 capture method provided in Example 1: the raw flue gas (temperature 40°C, CO2 concentration 15% by volume) is passed from bottom to top through the aforementioned device, so that the adsorbent 4 in the adsorbent bed 3 of the adsorption device 11 adsorbs the CO2 in the raw flue gas 1, resulting in clean flue gas 2; wherein the adsorption conditions include: space velocity of 5000 m 3 / (m 3 • h); Time is 15 min; When the CO2 concentration in the clean flue gas 2 reaches 15% by volume, adsorption stops, indicating that adsorption is complete. The pressure drop of the adsorbent bed was measured to be 800 Pa, and the CO2 adsorption capacity of the adsorbent was 6 wt%, which is 100% of the saturated adsorption capacity of the adsorbent.

[0081] Following the adsorbent regeneration method provided in Example 1, the desorption rate of the adsorbent was measured to be 71%.

[0082] Example 7 The CO2 capture device according to Example 1 is different in that the ratio of the height of each adsorbent bed 3 to the diameter of the support tube 5 is replaced with 25:1. According to the CO2 capture method provided in Example 1, the pressure drop of the adsorbent bed was measured to be 800 Pa, and the CO2 adsorption capacity of the adsorbent was 3.9 wt%, which is 70% of the saturated adsorption capacity of the adsorbent. Following the adsorbent regeneration method provided in Example 1, the desorption rate of the adsorbent was measured to be 65%.

[0083] Example 8 The CO2 capture device and CO2 capture method provided in Example 1 are the same, except that the adsorption conditions are replaced with a space velocity of 5500 m. 3 / (m 3 • h); Pressure: 20 kPa; Time: 20 min; The pressure drop of the adsorbent bed was measured to be 10,000 Pa, and the CO2 adsorption capacity of the adsorbent was 3.6 wt%. Following the adsorbent regeneration method provided in Example 1, the desorption rate of the adsorbent was measured to be 85%.

[0084] Comparative Example 1 The CO2 capture device provided in Example 1 differs in that the adsorption device does not contain three auxiliary feed ports for raw flue gas. Following the CO2 capture method provided in Example 1, the pressure drop of the adsorbent bed was measured to be 1000 kPa, and the CO2 adsorption capacity of the adsorbent was 3.2 wt%. Following the adsorbent regeneration method provided in Example 1, the desorption rate of the adsorbent was measured to be 70%.

[0085] Comparative Example 2 The CO2 capture device provided in Example 1 differs in that the adsorbent is replaced with columnar activated carbon adsorbent. Following the CO2 capture method provided in Example 1, the pressure drop of the adsorbent bed was measured to be 30 kPa, and the CO2 adsorption capacity of the adsorbent was 3 wt%. Following the adsorbent regeneration method provided in Example 1, the desorption rate of CO2 from the adsorbent in the flue gas was measured to be 50%.

[0086] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A CO2 capture device, characterized in that, The device includes: a feed pipeline, an adsorption unit, and a discharge pipeline connected in sequence; an online CO2 analyzer for feed and an online CO2 analyzer for discharge are respectively installed on the feed pipeline and the discharge pipeline; the adsorption unit has N adsorbent beds and N support tubes inside, and the support tubes are installed at the bottom of the adsorbent beds; the shell of the adsorption unit has "N-1" auxiliary feed ports for raw flue gas and "N-1" auxiliary online CO2 analyzers, and the auxiliary feed ports for raw flue gas and auxiliary online CO2 analyzers are arranged between two adjacent adsorbent beds; The adsorbent bed is filled with adsorbent, and the adsorbent is a honeycomb adsorbent; The adsorption device is used to adsorb CO2 in the raw flue gas and the adsorbent in the adsorbent bed to obtain clean flue gas; the feed CO2 online analyzer and the discharge CO2 online analyzer are used to monitor the CO2 content in the raw flue gas and the clean flue gas, respectively. The "N-1"th auxiliary online CO2 analyzer is used to monitor the CO2 content in the flue gas after the original flue gas passes through the "N-1"th adsorbent bed; The flow rate of the raw flue gas in the "N-1"th raw flue gas auxiliary feed port depends on the CO2 content in the "N-1"th auxiliary CO2 online analyzer; Where N is a positive integer and N≥2.

2. The apparatus according to claim 1, wherein, The height ratio of each adsorbent bed to the diameter of the support tube is 5-20:1; And / or, the height ratio of the adsorbent bed to the adsorption device is 0.5-0.9:1; And / or, the number of adsorbent beds is ≥1.

3. The apparatus according to claim 2, wherein, The height ratio of each adsorbent bed to the diameter of the support tube is 8-15:1; And / or, the height ratio of the adsorbent bed to the adsorption device is 0.6-0.8:1; And / or, the number of adsorbent beds is 2-10.

4. The apparatus according to claim 1, wherein, The bulk density of the adsorbent is ≤0.7 g / cm³. 3 ; And / or, the adsorbent is selected from at least one of carbon-based honeycomb adsorbents, amino-based honeycomb adsorbents, molecular sieve-based honeycomb adsorbents, and metal oxide-based honeycomb adsorbents.

5. The apparatus according to claim 4, wherein, The bulk density of the adsorbent is 0.45-0.65 g / cm³. 3 .

6. The apparatus according to claim 1, wherein, The support tube and the adsorbent bed are stacked alternately; And / or, the arrangement density of the support tubes is 0.1-1.

7. The apparatus according to claim 6, wherein, The arrangement density of the support tubes is 0.2-0.

6.

8. The apparatus according to any one of claims 1-7, wherein, The adsorption device is an axisymmetric reactor; And / or, the adsorption device further includes a gas distributor, and the gas distributor is disposed at the gas inlet of the adsorption device for distributing the raw flue gas.

9. The apparatus according to claim 8, wherein, The adsorption device is an axially fixed-bed reactor.

10. A method for capturing CO2, characterized in that, The method includes: passing the raw flue gas from bottom to top or from top to bottom through the device according to any one of claims 1-9, so that the adsorbent packed in the adsorbent bed of the adsorption device adsorbs CO2 in the raw flue gas to obtain clean flue gas; Wherein, the CO2 concentration in the clean flue gas is ≤ the CO2 concentration in the flue gas after passing through the Nth adsorbent bed is ≤ the CO2 concentration in the original flue gas.

11. The method according to claim 10, wherein, when When the flow rate is 80%, maintain the flow rate at the "N-1"th auxiliary flue gas inlet; or, when When the flow rate is greater than 80%, increase the flow rate of the "N-1"th auxiliary feed inlet of the raw flue gas.

12. The method according to claim 10, wherein, The CO2 concentration in the raw flue gas is ≤20% by volume. And / or, the temperature of the original flue gas is ≤45℃; And / or, the conditions for adsorption include: space velocity ≤ 5000 m 3 / (m 3 ·h); Pressure ≤10 kPa; Time ≤30 min; And / or, the pressure drop of the raw flue gas through the adsorbent bed is ≤2000 Pa; the linear velocity is ≤1 m / s.

13. The method according to claim 12, wherein, The CO2 concentration in the raw flue gas is 8-16% by volume. And / or, the temperature of the original flue gas is 20-40°C; And / or, the conditions for adsorption include: a space velocity of 1000-3500 m. 3 / (m 3 • h); Pressure: 3-8 kPa; Time: 5-25 min; And / or, the pressure drop of the raw flue gas through the adsorbent bed is 500-1500 Pa; the linear velocity is 0.1-0.5 m / s.

14. The method according to any one of claims 10-13, wherein, The method further includes: introducing a cooling medium into the N support tubes of the device for cooling, so that the adsorbent in the adsorbent bed is adsorbed; And / or, the flow rate of the cooling medium is 0.1-2 m / s; the temperature is 5-30℃.

15. The method according to claim 14, wherein, The flow rate of the cooling medium is 0.1-1 m / s; the temperature is 10-20℃.

16. A method for regenerating an adsorbent, characterized in that, The method is carried out in the apparatus according to any one of claims 1-9, wherein when the adsorption apparatus is in a shutdown state, the adsorbent packed in the adsorption apparatus in the shutdown state is desorbed and regenerated.

17. The method according to claim 16, wherein, The method includes the following steps: (1) Stop the feeding and discharging of the adsorption device; (2) Heat exchange medium is introduced into N support tubes in the adsorption device that is in a shutdown state to exchange heat, so that the adsorbent in the adsorbent bed is desorbed. And / or, the desorption conditions include: a temperature of 60-300°C; and a time of 5-60 min; And / or, the inlet temperature of the heat exchange medium is 100-350℃; the outlet temperature of the heat exchange medium is 80-200℃.

18. The method according to claim 17, wherein, The method includes the following steps: (1) Stop the feeding and discharging of the adsorption device; (2) Heat exchange medium is introduced into N support tubes in the adsorption device that is in a shutdown state to exchange heat, so that the adsorbent in the adsorbent bed is desorbed. And / or, the desorption conditions include: a temperature of 80-150°C; and a time of 10-30 min; And / or, the inlet temperature of the heat exchange medium is 100-250℃; the outlet temperature of the heat exchange medium is 80-150℃.

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