Separable solid adsorption decarbonization device and adsorption decarbonization method

Abstract

The invention discloses the technical field of solid adsorption decarburization, and particularly relates to a separable solid adsorption decarburization device and an adsorption decarburization method.The separable solid adsorption decarburization device comprises a CaO reaction bed and a CaCO3 reaction bed, the CaO reaction bed is filled with calcium oxide powder, the CaCO3 reaction bed is filled with calcium carbonate powder, the CaO reaction bed and the CaCO3 reaction bed are each provided with a heating rod, and the CaO reaction bed and the CaCO3 reaction bed are each provided with a heating rod. According to the invention, the combination of a thermochemical energy storage technology and a CO2 capture technology is proposed for the first time, so that the utilization efficiency of energy is improved, and the problems of high energy consumption and poor heat energy recovery of a traditional capture technology are solved. An efficient heat energy recovery system is designed, the operation cost is reduced, and the energy utilization rate is increased; the heat released in the adsorption stage is introduced into the CaCO3 reaction bed for heating, and heat energy exchange is performed through the heat exchange bed, so that not only is the trapping efficiency improved, but also the energy consumption in the desorption stage is greatly reduced, and the higher CO2 adsorption rate and decomposition efficiency are realized by accurately controlling the heating temperature and the operation process.

Description

Technical Field

[0001] The invention relates to the technical field of solid adsorption decarbonization, and in particular to a detachable solid adsorption decarbonization device and an adsorption decarbonization method. Background Art

[0002] Excessive carbon dioxide emissions have caused global climate change. Solid adsorbent materials have attracted more and more attention in the field of carbon dioxide adsorption due to their advantages such as recyclability and low loss in the regeneration process. The calcium looping (CaL) technology based on the carbonation / calcination cycle of calcium-based adsorbents to adsorb CO2 is a typical thermochemical energy storage technology, which mainly uses the endothermic / exothermic process of calcium-based adsorbents for chemical heat storage. In addition, this technology can also use calcium-based adsorbents (i.e. calcium oxide) to capture CO2 from the tail gas of existing thermal power plants and reduce the system's CO2 emissions.

[0003] Among them, how to couple the thermochemical energy storage of calcium-based adsorbents with CO2 capture to improve the thermal efficiency of the system is a problem that needs to be solved now. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above-mentioned existing problem of how to couple the thermochemical energy storage of calcium-based adsorbents with CO2 capture to improve the thermal efficiency of the system, the present invention is proposed.

[0006] Therefore, the object of the present invention is to provide a detachable solid adsorption decarbonization device.

[0007] To solve the above technical problems, the present invention provides the following technical solution: comprising a CaO reaction bed and a CaCO3 reaction bed, wherein the CaO reaction bed is filled with calcium oxide powder, the CaCO3 reaction bed is filled with calcium carbonate powder, and both the CaO reaction bed and the CaCO3 reaction bed are provided with heating rods.

[0008] In order to solve the above technical problems, the present invention also provides a detachable solid adsorption decarbonization method: comprising a detachable solid adsorption decarbonization device, and also comprising first keeping the CaO reaction bed and the CaCO3 reaction bed in contact; and then heating the temperature of the CaO reaction bed and the CaCO3 reaction bed to 400°C through power plant extraction steam.

[0009] As a preferred embodiment of the detachable solid adsorption decarbonization device of the present invention, the CaO reaction bed is introduced with pre-treated power plant flue gas containing carbon dioxide.

[0010] As a preferred embodiment of the detachable solid adsorption decarbonization device of the present invention, CaO+CO2→CaCO3 is an exothermic reaction, which is carried out in the CaO reaction bed, the rotating shaft drives the CaO reaction bed to rotate, and the solid particles turn over in the CaO reaction bed.

[0011] As a preferred embodiment of the detachable solid adsorption decarbonization device of the present invention, an automatic control system controls a mechanical screw to separate the CaO reaction bed and the CaCO3 reaction bed.

[0012] As a preferred solution of the detachable solid adsorption decarbonization device of the present invention, the CaCO3 reaction bed is electrically heated and continuously supplied with heat.

[0013] As a preferred embodiment of the detachable solid adsorption decarbonization device of the present invention, CO2 generated by the decomposition of CaCO3 at a high temperature of 900 degrees exchanges heat with exhaust steam in a heat exchange bed.

[0014] As a preferred embodiment of the detachable solid adsorption decarbonization device of the present invention, the air required for combustion of the power plant boiler is directly heated to recover the heat of the 900°C gas at the outlet of the reaction bed.

[0015] As a preferred embodiment of the detachable solid adsorption decarbonization device described in the present invention, the CaCO3 reaction bed is still in a high temperature state of 900 degrees Celsius after the above reaction is completed, dehumidified air is introduced, the air is heated by using the high temperature of 900 degrees Celsius, and the air is sent to the boiler for combustion, and finally the temperature of the CaCO3 reaction bed is reduced to 400°C.

[0016] As a preferred embodiment of the separable solid adsorption decarbonization device of the present invention, the material in the CaO bed after the above steps is CaCO3, and the material in the CaCO3 bed is CaO.

[0017] Beneficial effects of the present invention: During the technical implementation process of the present invention, the overall thermal efficiency of the system is significantly improved and CO2 emissions are effectively reduced by coupling CO2 capture and thermochemical energy storage.

[0018] This technical solution fully recovers the reaction heat in the adsorption stage and reuses the heat energy in the desorption stage, reducing energy waste and thus reducing the energy consumption of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0020] Figure 1 It is a schematic diagram of the adsorption stage of the detachable solid adsorption decarbonization device of the present invention.

[0021] Figure 2 It is a schematic diagram of the desorption stage of the detachable solid adsorption decarbonization device of the present invention.

[0022] Figure 3 It is a schematic diagram of the actual reaction bed of the separable solid adsorption decarbonization device of the present invention. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0026] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagram showing the structure of the bed will not be partially enlarged according to the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0027] Example 1, reference Figure 2 , which is the first embodiment of the present invention, provides a separable solid adsorption decarbonization device, including a CaO reaction bed and a CaCO3 reaction bed, the CaO reaction bed is filled with calcium oxide powder, the CaCO3 reaction bed is filled with calcium carbonate powder, and the CaO reaction bed and the CaCO3 reaction bed are both provided with heating rods. .

[0028] Example 2, reference Figure 1 to Figure 2 This embodiment is different from the first embodiment in that it provides a separable solid adsorption decarbonization method, including: first, keeping the CaO reaction bed and the CaCO3 reaction bed in contact; then heating the temperature of the CaO reaction bed and the CaCO3 reaction bed to 400°C through power plant extraction steam. Since the reaction rate of CaO and CO2 is faster at this temperature, it is beneficial to improve the adsorption efficiency and at the same time fully utilizes the heat of the power plant extraction steam (from the high-pressure cylinder), which is the first step of the step heating.

[0029] Specifically, the CaO reaction bed is fed with pre-treated power plant flue gas containing carbon dioxide.

[0030] In this process, CaO reacts with CO2 to generate CaCO3, i.e.: CaO+CO2→CaCO3. The flue gas of the power plant contains some water vapor, which will damage the pore structure of the CaO filler and requires pretreatment to remove moisture. The CO2 contained in the flue gas reacts chemically with the CaO filler. This step is the adsorption link of CO2, and the adsorption rate can reach more than 40%, which is an important indicator for judging the adsorption effect; the flue gas at the outlet of the power plant is slightly pressurized after passing through the induced draft fan. It only needs to connect the pipeline and separate a stream of flue gas to directly enter the CaO reaction bed.

[0031] Furthermore, CaO+CO2→CaCO3 is an exothermic reaction, which is carried out in the CaO reaction bed. The rotating shaft drives the CaO reaction bed to rotate, and the solid particles turn over in the CaO reaction bed. Since the two reaction beds keep in contact and have good heat transfer efficiency (the material is ceramic with good thermal conductivity, and liquid metal lubricant is added at the same time), the heat released by the reaction flows into the CaCO3 reaction bed, further heating it to 500°C, and step heating is the second step. After the reaction, the CaO in the reaction bed becomes CaCO3.

[0032] It should be noted that the above steps are the adsorption stage.

[0033] The rest of the structure is the same as that of Example 1.

[0034] Example 3, reference Figure 1 to Figure 2 This embodiment is different from the above embodiments in that the automatic control system controls the mechanical screw to separate the CaO reaction bed and the CaCO3 reaction bed. The CaCO3 reaction bed needs to be continuously heated, but the CaO reaction bed does not need to be continuously heated so they are separated.

[0035] Specifically, the CaCO3 reaction bed is electrically heated and continuously supplied with heat, and energy is required to maintain the decomposition reaction CaCO3→CaO+CO2 (desorption reaction). The reaction can occur simply by heating.

[0036] Furthermore, the CO2 generated by the decomposition of CaCO3 at a high temperature of 900 degrees exchanges heat with the exhaust steam in the heat exchange bed, thereby achieving the effect of heat recovery. After the reaction, the CaCO3 in the reaction bed is converted into CaO. During the reaction, the shaft drives the reaction bed to rotate.

[0037] Furthermore, the air required for combustion in the power plant boiler is directly heated, and the heat of the 900°C gas at the outlet of the reaction bed is recovered.

[0038] Furthermore, after the above reaction is completed, the CaCO3 reaction bed is still in a high temperature state of 900 degrees Celsius. Dehumidified air is introduced, the air is heated by the high temperature of 900 degrees Celsius, and the air is sent to the boiler for combustion, and finally the temperature of the CaCO3 reaction bed is reduced to 400°C. At this time, the automatic control system controls the screw to rotate in and contact the CaO reaction bed again, and then the above steps need to be repeated according to actual needs.

[0039] It should be noted that the above steps in this embodiment are the desorption stage.

[0040] Furthermore, after the above steps, the material in the CaO bed is CaCO3, and the material in the CaCO3 bed is CaO. At this time, the above steps can be repeated according to actual needs.

[0041] It should be noted that this step is a circulation stage, at which the material in the original CaO bed is CaCO3, and the material in the original CaCO3 bed is CaO, and then the above operation is repeated.

[0042] The rest of the structure is the same as that of Example 2.

[0043] Operation process: The experimental device is set to be cylindrical, with specific parameters of 1.5 meters in length, 80 centimeters in inner diameter, and 120 centimeters in shell diameter. The CaO filler is 0.8m3, the CaCO3 filler is 0.8m3, and the flue gas treatment volume is 30 liters per hour. In the adsorption stage, the outer sleeve is in contact with the inner sleeve. The outer sleeve material is silicon carbide ceramic, and the inner cylinder is silicon carbide ceramic. Liquid metal lubricant is coated between the outer shell and the sleeve to enhance heat conduction and lubrication.

[0044] The outer sleeve is heated to 500°C and simulated power plant flue gas (15% CO2, excluding H2O) is introduced. The CO2 adsorption rate is 40%. At the same time, the heat is transferred to the inner sleeve due to contact with the inner sleeve, and the inner sleeve is also heated to about 500°C.

[0045] The outer ring shell and the inner cylinder are separated, and the inner cylinder is continued to be heated to 900 degrees Celsius. Maintaining the decomposition temperature of CaCO3 requires 4.8GJ / tCO2 energy. The 900-degree Celsius high-temperature CO2 gas is discharged into the waste heat recovery device, and the CO2 is reduced to 100 degrees Celsius and stored. Then air is introduced into the inner cylinder, and the high-temperature air is discharged into the waste heat recovery device, recovering a total of 2.2GJ / tCO2 of heat.

[0046] It should be noted that the present invention proposes for the first time to combine thermochemical energy storage technology with CO2 capture technology to improve energy utilization efficiency and solve the problems of high energy consumption and poor heat recovery of traditional capture technology. An efficient heat recovery system is designed to reduce operating costs and improve energy utilization.

[0047] The heat released during the adsorption stage is introduced into the CaCO3 reaction bed for heating, and heat energy is exchanged through the heat exchange bed, which not only improves the capture efficiency, but also greatly reduces the energy consumption in the desorption stage. By precisely controlling the heating temperature and operating process, a higher CO2 adsorption rate and decomposition efficiency are achieved.

[0048] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0049] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0050] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0051] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A detachable solid adsorption decarbonization device, characterized in that: It comprises a CaO reaction bed and a CaCO3 reaction bed, wherein the CaO reaction bed is filled with calcium oxide powder, the CaCO3 reaction bed is filled with calcium carbonate powder, and both the CaO reaction bed and the CaCO3 reaction bed are provided with heating rods.

2. A separable solid adsorption decarbonization method, characterized in that: The detachable solid adsorption decarbonization device according to claim 1 further comprises: First, the CaO reaction bed and the CaCO3 reaction bed are kept in contact; Then, the temperature of the CaO reaction bed and the CaCO3 reaction bed is heated to 400°C by extracting steam from the power plant.

3. The separable solid adsorption decarbonization method according to claim 2, characterized in that: The CaO reaction bed is fed with pre-treated power plant flue gas containing carbon dioxide.

4. The detachable solid adsorption decarbonization method according to claim 3, characterized in that: CaO+CO2→CaCO3 is an exothermic reaction, which is carried out in the CaO reaction bed. The rotating shaft drives the CaO reaction bed to rotate, and the solid particles turn over in the CaO reaction bed.

5. The detachable solid adsorption decarbonization method according to claim 4, characterized in that: The automatic control system controls the mechanical screw to separate the CaO reaction bed and the CaCO3 reaction bed.

6. The detachable solid adsorption decarbonization method according to claim 5, characterized in that: The CaCO3 reaction bed is electrically heated and heat is continuously supplied.

7. The detachable solid adsorption decarbonization method according to claim 6, characterized in that: The CO2 generated by the decomposition of CaCO3 at a high temperature of 900 degrees exchanges heat with the exhaust steam in the heat exchange bed.

8. The detachable solid adsorption decarbonization method according to claim 6, characterized in that: Directly heat the air required for combustion in the power plant boiler and recover the heat of the 900℃ gas at the outlet of the reaction bed.

9. The separable solid adsorption decarbonization method according to claim 7 or 8, characterized in that: After the above reaction is completed, the CaCO3 reaction bed is still in a high temperature state of 900 degrees Celsius. Dehumidified air is introduced, the air is heated by the 900 degrees Celsius high temperature, and the air is sent to the boiler for combustion, and finally the temperature of the CaCO3 reaction bed is reduced to 400°C.

10. The detachable solid adsorption decarbonization method according to claim 9, characterized in that: After the above steps, the material in the CaO bed is CaCO3, and the material in the CaCO3 bed is CaO.

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