A thermal storage combustible solid waste gasification treatment system and CO2 enrichment method

Abstract

The present invention discloses a heat storage type combustible solid waste gasification disposal system and a CO2 enrichment method, which relate to the field of solid waste resource treatment. The system includes a pyrolysis furnace, a combustion chamber, two sets of chemical heat storage beds, a CO2 gas storage tank, a pyrolysis gas heat exchange pipeline, a heat transfer medium circulation pipeline and various sets of reversing valves. The high-temperature pyrolysis gas generated by the pyrolysis of organic solid waste in the pyrolysis furnace is used as a heat source and is stored in a chemical heat storage bed; the low-temperature pyrolysis gas after heat storage enters another set of chemical heat storage beds for exothermic reaction, and the generated heat energy is fed back to the pyrolysis furnace through a circulation pipeline for temperature control; the pyrolysis gas is then passed into the combustion chamber of the pyrolysis furnace for combustion to achieve recycling, and the exhaust gas after combustion enters the heat storage bed for reaction absorption. The high-concentration CO2 and water vapor mixture generated during the heat storage process enters the CO2 gas storage tank for condensation and enrichment. The present invention can achieve energy self-sufficiency, improve energy utilization efficiency, and reduce secondary pollutant emissions.

Description

Technical Field

[0001] The present invention relates to the field of solid waste resource treatment, and in particular to a heat storage type combustible solid waste gasification disposal system and a CO2 enrichment method. Background Art

[0002] With the acceleration of urbanization in my country, the production of municipal solid waste has increased dramatically. Municipal solid waste contains a large amount of combustible solid waste such as agricultural and forestry waste, organic components of domestic garbage, and urban sludge. Random stacking or improper treatment of these wastes will cause secondary pollution and also result in a large amount of organic matter waste. However, due to the complexity of combustible solid waste, high moisture content, and diverse pollutants, traditional treatment methods make it difficult to control its resource utilization. Municipal solid waste pyrolysis is considered to be one of the most promising thermochemical treatment technologies for achieving the goals of solid waste reduction, stabilization, harmlessness, and resource utilization due to its advantages such as good economy, low secondary pollution, and high utilization value of pyrolysis products.

[0003] Currently, thermal treatment technology has low thermal efficiency. The high-temperature pyrolysis gas produced by pyrolysis has a complex composition, including high CO2 and moisture content, which significantly reduces its calorific value. The primary method for treating pyrolysis gas is to recycle it for energy recycling. However, the low calorific value and resulting in unstable combustion significantly limit its application. Furthermore, the large amount of exhaust gas emitted also creates secondary pollution. The use of additional pyrolysis gas purification technology increases energy consumption and is prohibitively expensive. Summary of the Invention

[0004] In response to the deficiencies in the prior art, the present invention provides a heat storage type combustible solid waste gasification disposal system and a CO2 enrichment method, which utilizes a chemical heat storage bed to store heat for high-temperature pyrolysis gas; then utilizes the low-temperature pyrolysis gas and the CO2 and water vapor in the combustion exhaust gas to react with the heat storage material of the chemical heat storage bed to exothermic reaction, and feeds the heat back to the pyrolysis furnace, which can improve energy utilization efficiency and reduce secondary pollutant emissions.

[0005] To achieve the above object, the present invention can be carried out using the following technical solutions:

[0006] A heat storage combustible solid waste gasification treatment system, comprising:

[0007] A pyrolysis furnace is provided with a pyrolysis gas outlet, a heat transfer medium outlet and a heat transfer medium inlet;

[0008] A first chemical heat storage bed and a second chemical heat storage bed are both provided with heat storage materials, the first chemical heat storage bed is provided with a first heat transfer medium circulation pipe and a first pyrolysis gas heat exchange pipe, and the second chemical heat storage bed is provided with a second heat transfer medium circulation pipe and a second pyrolysis gas heat exchange pipe;

[0009] The CO2 gas storage tank is connected to the first chemical thermal storage bed and the second chemical thermal storage bed through pipelines, wherein:

[0010] The pyrolysis gas outlet is connected to the inlet ends of the first pyrolysis gas heat exchange pipe and the second pyrolysis gas heat exchange pipe respectively through a pipe with a first two-way reversing valve, the heat transfer medium outlet is connected to the inlet ends of the first heat transfer medium circulation pipe and the second heat transfer medium circulation pipe respectively through a pipe with a second two-way reversing valve, and the heat transfer medium inlet is connected to the outlet ends of the first heat transfer medium circulation pipe and the second heat transfer medium circulation pipe respectively through a pipe with a fourth two-way reversing valve;

[0011] Heat storage and heat release processes are alternately performed in the first chemical thermal storage bed and the second chemical thermal storage bed.

[0012] As described above, the heat storage type combustible solid waste gasification treatment system further comprises the following: the pyrolysis furnace is provided with a heat conducting medium jacket, and the heat conducting medium outlet and the heat conducting medium inlet are both provided on the heat conducting medium jacket.

[0013] The heat storage type combustible solid waste gasification treatment system as described above, further, a combustion chamber is provided below the pyrolysis furnace, and the combustion chamber is provided with an air intake pipeline and a compensation fuel gas intake pipeline.

[0014] As described above, the heat storage type combustible solid waste gasification treatment system, further, a combustion chamber is provided below the pyrolysis furnace, and the combustion chamber is provided with a combustion exhaust gas outlet and a pyrolysis gas combustion inlet, wherein the pyrolysis gas combustion inlet is respectively connected to the first chemical heat storage bed and the second chemical heat storage bed through a pipeline with a third two-way reversing valve; the combustion exhaust gas outlet is respectively connected to the first pyrolysis gas heat exchange pipeline and the second pyrolysis gas heat exchange pipeline through a pipeline with a fifth two-way reversing valve, and then connected to the first chemical heat storage bed and the second chemical heat storage bed through a sixth two-way reversing valve.

[0015] The thermal storage type combustible solid waste gasification disposal system as described above, further, solid waste is placed in the pyrolysis furnace.

[0016] As described above, the heat storage type combustible solid waste gasification treatment system, further, the first heat transfer medium circulation pipeline, the first pyrolysis gas heat exchange pipeline, the second heat transfer medium circulation pipeline and the second pyrolysis gas heat exchange pipeline are all arranged in a serpentine shape.

[0017] At the same time, the present invention also discloses a CO2 enrichment method, which is carried out using the above-mentioned thermal storage combustible solid waste gasification disposal system, and includes the following steps:

[0018] Supplementary fuel gas and air are introduced into the pyrolysis furnace and heated to a pyrolysis temperature of 500-800°C. The solid waste in the pyrolysis furnace is pyrolyzed to produce pyrolysis gas. The 400-600°C pyrolysis gas enters the first pyrolysis gas heat exchange pipe and the second pyrolysis gas heat exchange pipe for heat storage.

[0019] During the heat storage process, the heat storage material decomposes under heat to produce CO2 and water vapor. The CO2 and water vapor enter the CO2 gas storage tank. After cooling, the water vapor condenses to achieve CO2 enrichment.

[0020] The pyrolysis gas in the range of 150-200℃ enters the first chemical heat storage bed and the second chemical heat storage bed again, and the CO2 and water vapor in the pyrolysis gas react with the heat storage material to release heat; at the same time, the 300-500℃ heat transfer medium enters the second heat transfer medium circulation pipeline to exchange heat with the second chemical heat storage bed undergoing an exothermic reaction, and then the heat transfer medium is heated to 500-800℃, and then enters the heat transfer medium jacket to provide heat for the temperature control of the pyrolysis furnace.

[0021] In the CO2 enrichment method as described above, further, the pyrolysis gas at 200-300°C discharged from the second chemical thermal storage bed after the exothermic reaction re-enters the combustion chamber of the pyrolysis furnace for combustion.

[0022] In the CO2 enrichment method described above, further, the heat storage material is MgO or CaO and the matrix composite material chemical heat storage bed, and the following reactions occur during the heat storage and release process:

[0023] Thermal storage process: XCO3→XO+CO2; X(OH)2→XO+H2O, where X is Mg or Ca

[0024] Exothermic process: XO+CO2→XCO3; XO+H2O→X(OH)2, where X is Mg or Ca.

[0025] In the CO2 enrichment method as described above, further, the concentration of CO2 in the pyrolysis gas after the exothermic reaction is less than 20%, and the concentration of water vapor is less than 10%.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. Using high-temperature pyrolysis gas as a heat source and combining the first and second chemical thermal storage beds to recycle waste heat can improve the overall thermal utilization efficiency of the device;

[0028] 2. The low-temperature pyrolysis gas and CO2 and water vapor in the combustion exhaust react with the heat storage material in the chemical thermal storage bed to release heat, and the heat is fed back to the pyrolysis furnace. The purified combustible pyrolysis gas heats the pyrolysis furnace through combustion, which can achieve self-sufficiency in pyrolysis energy.

[0029] 3. The CO2 generated by this system can be efficiently recovered through the CO2 gas storage tank, which can reduce the emission of secondary pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 This is a structural diagram of a thermal storage combustible solid waste gasification treatment system according to an embodiment of the present invention.

[0032] Among them: 1. First heat transfer medium circulation pipeline; 2. First pyrolysis gas heat exchange pipeline; 3. Heat storage material; 4. First chemical heat storage bed; 5. CO2 gas storage tank; 6. First two-way reversing valve; 7. Second chemical heat storage bed; 8. Second two-way reversing valve; 9. Pyrolysis gas outlet; 10. Heat transfer medium outlet; 11. Heat transfer medium jacket; 12. Pyrolysis furnace; 13. Solid waste; 14. Air intake pipeline; 15. Compensating gas intake pipeline; 16. Combustion chamber; 17. Heat transfer medium inlet; 18. Combustion exhaust gas outlet; 19. Pyrolysis gas combustion inlet; 20. Third two-way reversing valve; 21. Fourth two-way reversing valve; 22. Fifth two-way reversing valve; 23. Sixth two-way reversing valve; 24. First gas enrichment pipeline; 25. Second gas enrichment pipeline; 26. Second pyrolysis gas heat exchange pipeline; 27. Second heat transfer medium circulation pipeline. DETAILED DESCRIPTION

[0033] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] Example:

[0035] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0037] In the description of the present invention, "plurality" means at least two, such as two or three, unless otherwise specifically defined. Furthermore, unless otherwise specified or defined, the terms "mounted," "connected," and "connected" should be understood broadly, meaning, for example, fixed, removable, or integral; mechanical or electrical; direct or indirect through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention.

[0038] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0039] See also Figure 1The present invention discloses a heat storage type combustible solid waste gasification disposal system and a CO2 enrichment method. The system uses the high-temperature pyrolysis gas generated by the pyrolysis of organic solid waste in the pyrolysis furnace 12 as a heat source, and utilizes a chemical heat storage bed for heat storage; the low-temperature pyrolysis gas after heat storage enters another set of chemical heat storage beds for exothermic reaction, and the generated heat energy is fed back to the pyrolysis furnace 12 through a circulation pipeline for temperature control; the pyrolysis gas is then passed into the combustion chamber 16 of the pyrolysis furnace 12 for combustion and recycling, and the exhaust gas after combustion enters the chemical heat storage bed for reaction absorption. In addition, the high-concentration CO2 and water vapor mixture generated during the heat storage process enters the CO2 gas storage tank 5 for condensation and enrichment. The present invention can achieve energy self-sufficiency, improve energy utilization efficiency, and reduce secondary pollutant emissions.

[0040] See also Figure 1 A heat storage type combustible solid waste gasification treatment system may include: a pyrolysis furnace 12, a first chemical heat storage bed 4 and a second chemical heat storage bed 7, both of which are provided with heat storage materials 3, and a CO2 gas storage tank 5. The pyrolysis furnace 12 is provided with a pyrolysis gas outlet 9, a heat transfer medium outlet 10 and a heat transfer medium inlet 17; the first chemical heat storage bed 4 is provided with a first heat transfer medium circulation pipeline 1 and a first pyrolysis gas heat exchange pipeline 2, and the second chemical heat storage bed 7 is provided with a second heat transfer medium circulation pipeline 27 and a second pyrolysis gas heat exchange pipeline 26; the CO2 gas storage tank 5 is connected to the first chemical heat storage bed 4 and the second chemical heat storage bed 7 through pipelines, respectively. Among them, the pyrolysis gas outlet 9 is respectively connected to the inlet ends of the first pyrolysis gas heat exchange pipe 2 and the second pyrolysis gas heat exchange pipe 26 through a pipe with a first two-way reversing valve 6, the heat transfer medium outlet 10 is respectively connected to the inlet ends of the first heat transfer medium circulation pipe 1 and the second heat transfer medium circulation pipe 27 through a pipe with a second two-way reversing valve 8, and the heat transfer medium inlet 17 is respectively connected to the outlet ends of the first heat transfer medium circulation pipe 1 and the second heat transfer medium circulation pipe 27 through a pipe with a fourth two-way reversing valve 21; the first chemical thermal storage bed 4 and the second chemical thermal storage bed 7 perform heat storage and heat release processes alternately.

[0041] In this embodiment, the pyrolysis gas outlet 9 is located at the top of the pyrolysis furnace 12 and is connected to the first pyrolysis gas heat exchange pipe 2 within the first chemical thermal storage bed 4 and the second pyrolysis gas heat exchange pipe 26 within the second chemical thermal storage bed 7 via a first two-way reversing valve 6. By switching the first two-way reversing valve 6, the high-temperature pyrolysis gas is alternately fed into the first pyrolysis gas heat exchange pipe 2 or the second pyrolysis gas heat exchange pipe 26 for thermal storage. During this thermal storage process, the thermal storage material 3 is decomposed under high temperature. The CO2 and water vapor produced by the decomposition enter the CO2 storage tank 5 through the first gas enrichment pipe 24 or the second gas enrichment pipe 25, where the CO2 is enriched through condensation of the water vapor.

[0042] The heat transfer medium outlet 10 is connected to the first heat transfer medium circulation conduit 1 within the first chemical thermal storage bed 4 and the second heat transfer medium circulation conduit 27 within the second chemical thermal storage bed 7 via the second two-way reversing valve 8. After the heat storage process is completed, the low-temperature pyrolysis gas enters the interior of the first chemical thermal storage bed 4 or the second chemical thermal storage bed 7 through the fifth two-way reversing valve 22 and the sixth two-way reversing valve 23, where it reacts with the thermal storage material 3, releasing a large amount of heat. It can be understood that this embodiment, by combining two sets of chemical thermal storage beds with multiple sets of two-way reversing valves, can achieve periodic alternating operation, thereby achieving a continuous effect of heat recovery, purification, combustion, and CO2 enrichment of the pyrolysis gas.

[0043] In the above embodiment, further, the pyrolysis furnace 12 is provided with a heat-conducting medium jacket 11, and the heat-conducting medium outlet 10 and the heat-conducting medium inlet 17 are both provided on the heat-conducting medium jacket 11. Specifically, the heat-conducting medium outlet 10 is provided on the top side of the heat-conducting medium jacket 11 of the pyrolysis furnace 12, and the heat-conducting medium inlet 17 is provided on the bottom side of the heat-conducting medium jacket 11 of the pyrolysis furnace 12. The temperature control range of the heat-conducting medium inside the heat-conducting medium jacket 11 is 500-800°C. The heat-conducting medium can enter the first heat-conducting medium circulation pipe 1 or the second heat-conducting medium circulation pipe 27 through the second two-way reversing valve 8, exchange heat with the chemical heat storage bed undergoing an exothermic reaction to increase the temperature, and the heated heat-conducting medium then enters the heat-conducting medium jacket 11 through the fourth two-way reversing valve 21 to provide heat to the pyrolysis furnace 12, so that the system can achieve energy self-sufficiency in pyrolysis, thereby improving the overall heat utilization efficiency of the system.

[0044] As an optional implementation, in some embodiments, a combustion chamber 16 is provided below the pyrolysis furnace 12 , and the combustion chamber 16 is provided with an air intake pipeline 14 and a compensation gas intake pipeline 15 .

[0045] In this embodiment, the combustion chamber 16 is equipped with an air inlet line 14 and a makeup gas inlet line 15, both of which feature flow control. After the exothermic reaction, the low-temperature pyrolysis gas exiting the chemical heat storage bed passes through a third two-way reversing valve 20 and enters the combustion chamber 16 of the pyrolysis furnace 12 to participate in combustion. The energy required for pyrolysis is self-sufficient from the combustion of the purified pyrolysis gas. The makeup gas inlet line 15 can be used to adjust and appropriately supplement the calorific value of different organic solid waste types. The exhaust gas from the combustion passes through a fifth two-way reversing valve 22 and is mixed with the low-temperature pyrolysis gas to participate in the exothermic reaction of the chemical heat storage bed.

[0046] As an optional embodiment, in some embodiments, a combustion chamber 16 is provided below the pyrolysis furnace 12, and the combustion chamber 16 is provided with a combustion exhaust gas outlet 18 and a pyrolysis gas combustion inlet 19, wherein the pyrolysis gas combustion inlet 19 is connected to the first chemical heat storage bed 4 and the second chemical heat storage bed 7 respectively through a pipeline with a third two-way reversing valve 20; the combustion exhaust gas outlet 18 is connected to the first pyrolysis gas heat exchange pipeline 2 and the second pyrolysis gas heat exchange pipeline 26 respectively through a pipeline with a fifth two-way reversing valve 22, and then connected to the first chemical heat storage bed 4 and the second chemical heat storage bed 7 respectively through a sixth two-way reversing valve 23.

[0047] As an optional implementation, in some embodiments, solid waste 13 is placed in the pyrolysis furnace 12 .

[0048] As an optional embodiment, in certain embodiments, the first heat transfer medium circulation conduit 1, the first pyrolysis gas heat exchange conduit 2, the second heat transfer medium circulation conduit 27, and the second pyrolysis gas heat exchange conduit 26 are all arranged in a serpentine manner. Specifically, the first heat transfer medium circulation conduit 1, the first pyrolysis gas heat exchange conduit 2, the second heat transfer medium circulation conduit 27, and the second pyrolysis gas heat exchange conduit 26 are all arranged in a serpentine manner, which can increase the contact area between the heat transfer medium circulation conduit and the pyrolysis gas heat exchange conduit, thereby improving heat exchange efficiency.

[0049] In order to better understand the present invention, the working process of the system is described below.

[0050] Heat storage stage: When the chemical heat storage bed is in the heat storage state, the pyrolysis furnace 12 passes the high-temperature pyrolysis gas generated by the pyrolysis of the solid waste 13 through the first two-way reversing valve 6 and flows through the pyrolysis gas heat exchange pipeline to store heat in the chemical heat storage bed. During the heat storage process, the CO2 and water vapor mixture generated by the decomposition of the heat storage material 3 enters the CO2 gas storage tank 5 through the first gas enrichment pipeline 24 or the second gas enrichment pipeline 25. The water vapor is condensed and removed in the CO2 gas storage tank 5, and high-purity CO2 is enriched.

[0051] Heat release phase: When the chemical heat storage bed is in the heat release phase, the low-temperature pyrolysis gas after the heat storage process is introduced into the chemical heat storage bed through the fifth two-way reversing valve 22 and the sixth two-way reversing valve 23. The CO2 and water vapor in the low-temperature pyrolysis gas react with the heat storage material 3 in an exothermic reaction. Simultaneously, the medium-temperature heat transfer medium in the jacket layer of the pyrolysis furnace 12 is transported through the second two-way reversing valve 8 into the heat transfer medium circulation pipeline to recover heat from the chemical heat storage bed. The high-temperature circulating medium, having absorbed heat energy, returns to the jacket layer of the pyrolysis furnace 12 through the fourth two-way reversing valve 21 to control the temperature within the furnace. The low-temperature pyrolysis gas, after absorbing CO2 and water vapor, passes through the third two-way reversing valve 20 and enters the combustion chamber 16 of the pyrolysis furnace 12 for combustion, providing heat for the pyrolysis process. The exhaust gas from the combustion is mixed with the low-temperature pyrolysis gas and participates in the exothermic reaction of the chemical heat storage bed.

[0052] It can be understood that two groups of chemical heat storage beds, in conjunction with multiple groups of two-way reversing valves, can realize periodic alternating operation, thereby achieving the continuous effect of pyrolysis gas heat recovery, purification, combustion and CO2 enrichment.

[0053] In addition, the present invention also provides a CO2 enrichment method, which is carried out using the above-mentioned thermal storage combustible solid waste gasification disposal system, and can include the following steps:

[0054] The pyrolysis furnace 12 is heated to a pyrolysis temperature of 500-800°C by using the air intake pipe 14 and the compensation gas intake pipe 15. After the solid waste 13 in the pyrolysis furnace 12 is pyrolyzed, a large amount of pyrolysis gas is generated. The 400-600°C pyrolysis gas is discharged from the pyrolysis gas outlet 9, passes through the first two-way reversing valve 6 and enters the first pyrolysis gas heat exchange pipe 2 and the second pyrolysis gas heat exchange pipe 26 for heat storage; during the heat storage process, the heat storage material 3 is heated and decomposed to produce a large amount of CO2 and water vapor. The mixed gas of CO2 and water vapor enters the CO2 gas storage tank 5 through the first gas enrichment pipe 24 or the second gas enrichment pipe 25. After cooling, the water vapor condenses to achieve CO2 enrichment.

[0055] After the heat storage process, the low-temperature pyrolysis gas in the range of 150-200°C enters the first chemical heat storage bed 4 and the second chemical heat storage bed 7 again, and the CO2 and water vapor in the pyrolysis gas react with the heat storage material 3 to release heat; at the same time, the 300-500°C heat transfer medium enters the second heat transfer medium circulation pipe 27 to exchange heat with the second chemical heat storage bed 7 undergoing an exothermic reaction, and then the heat transfer medium is heated to 500-800°C, and then enters the heat transfer medium jacket 11 to provide heat for temperature control of the pyrolysis furnace 12.

[0056] After the exothermic reaction, the low-temperature pyrolysis gas (200-300°C) discharged from the second chemical thermal storage bed 7 passes through the third two-way reversing valve 20 and enters the combustion chamber 16 of the pyrolysis furnace 12 to participate in combustion. The energy required for pyrolysis is self-sufficient from the combustion of the purified pyrolysis gas. The pyrolysis gas composition and calorific value vary depending on the organic solid waste. The calorific value can be adjusted appropriately through the compensating gas inlet pipeline 15 to control the temperature of the pyrolysis furnace 12 within the range of 500-800°C. The exhaust gas after combustion passes through the fifth two-way reversing valve 22 and is mixed with the low-temperature pyrolysis gas to participate in the exothermic reaction of the chemical thermal storage bed.

[0057] It can be understood that in this method, two groups of chemical heat storage beds cooperate with multiple groups of two-way reversing valves to achieve periodic alternating operation, and the heat storage and release switching time is 1200-3600 seconds, thereby ultimately achieving the continuous effect of pyrolysis gas heat recovery, pyrolysis gas purification, pyrolysis gas combustion and CO2 enrichment.

[0058] In addition, in this embodiment, the heat storage material is an existing chemical material, which can be MgO or CaO and their matrix composite materials, preferably MgO or MgO-based composite heat storage material. The following reactions occur during the heat storage and release process of the chemical heat storage bed:

[0059] Thermal storage process: XCO3→XO+CO2; X(OH)2→XO+H2O, where X is Mg or Ca;

[0060] Exothermic process: XO+CO2→XCO3; XO+H2O→X(OH)2, where X is Mg or Ca.

[0061] Furthermore, in certain embodiments, the concentration of CO 2 in the pyrolysis gas after the exothermic reaction is less than 20%, and the concentration of water vapor is less than 10%.

[0062] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0063] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the essence of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A thermal storage combustible solid waste gasification treatment system, characterized in that: include: A pyrolysis furnace is provided with a pyrolysis gas outlet, a heat transfer medium outlet and a heat transfer medium inlet; A first chemical heat storage bed and a second chemical heat storage bed are both provided with heat storage materials, the first chemical heat storage bed is provided with a first heat transfer medium circulation pipe and a first pyrolysis gas heat exchange pipe, and the second chemical heat storage bed is provided with a second heat transfer medium circulation pipe and a second pyrolysis gas heat exchange pipe; The CO2 gas storage tank is connected to the first chemical thermal storage bed and the second chemical thermal storage bed through pipelines, wherein: The pyrolysis gas outlet is connected to the inlet ends of the first pyrolysis gas heat exchange pipe and the second pyrolysis gas heat exchange pipe respectively through a pipe with a first two-way reversing valve. The heat transfer medium outlet is connected to the inlet ends of the first heat transfer medium circulation pipe and the second heat transfer medium circulation pipe respectively through a pipe with a second two-way reversing valve. The heat transfer medium inlet is connected to the outlet ends of the first heat transfer medium circulation pipe and the second heat transfer medium circulation pipe respectively through a pipe with a fourth two-way reversing valve. The outlet ends of the first pyrolysis gas heat exchange pipe and the second pyrolysis gas heat exchange pipe return to the first chemical thermal storage bed and the second chemical thermal storage bed respectively through a fifth two-way reversing valve and a sixth two-way reversing valve. Heat storage and heat release processes are alternately performed in the first chemical thermal storage bed and the second chemical thermal storage bed.

2. The thermal storage type combustible solid waste gasification treatment system according to claim 1 is characterized in that: The pyrolysis furnace is provided with a heat-conducting medium jacket, and the heat-conducting medium outlet and the heat-conducting medium inlet are both arranged on the heat-conducting medium jacket.

3. The thermal storage type combustible solid waste gasification treatment system according to claim 1, characterized in that: A combustion chamber is provided below the pyrolysis furnace, and the combustion chamber is provided with an air intake pipeline and a compensation gas intake pipeline.

4. The thermal storage type combustible solid waste gasification treatment system according to claim 1, characterized in that: A combustion chamber is provided below the pyrolysis furnace. The combustion chamber is provided with a combustion exhaust gas outlet and a pyrolysis gas combustion inlet, wherein the pyrolysis gas combustion inlet is connected to the first chemical heat storage bed and the second chemical heat storage bed respectively through a pipeline with a third two-way reversing valve; the combustion exhaust gas outlet is connected to the first pyrolysis gas heat exchange pipeline and the second pyrolysis gas heat exchange pipeline respectively through a pipeline with a fifth two-way reversing valve, and then connected to the first chemical heat storage bed and the second chemical heat storage bed respectively through a sixth two-way reversing valve.

5. The thermal storage type combustible solid waste gasification treatment system according to claim 1, characterized in that: Solid waste is placed in the pyrolysis furnace.

6. The thermal storage type combustible solid waste gasification treatment system according to claim 1, characterized in that: The first heat transfer medium circulation pipeline, the first pyrolysis gas heat exchange pipeline, the second heat transfer medium circulation pipeline and the second pyrolysis gas heat exchange pipeline are all arranged in a serpentine shape.

7. A CO2 enrichment method, characterized in that: The method is carried out using the thermal storage type combustible solid waste gasification treatment system according to any one of claims 1 to 6, and comprises the following steps: Supplementary fuel gas and air are introduced into the pyrolysis furnace and heated to a pyrolysis temperature of 500-800°C. The solid waste in the pyrolysis furnace is pyrolyzed to produce pyrolysis gas. The 400-600°C pyrolysis gas enters the first pyrolysis gas heat exchange pipe and the second pyrolysis gas heat exchange pipe for heat storage. During the heat storage process, the heat storage material decomposes under heat to produce CO2 and water vapor. The CO2 and water vapor enter the CO2 gas storage tank. After cooling, the water vapor condenses to achieve CO2 enrichment. The pyrolysis gas in the range of 150-200℃ enters the first chemical heat storage bed and the second chemical heat storage bed again, and the CO2 and water vapor in the pyrolysis gas react with the heat storage material to release heat; at the same time, the 300-500℃ heat transfer medium enters the second heat transfer medium circulation pipeline to exchange heat with the second chemical heat storage bed undergoing an exothermic reaction, and then the heat transfer medium is heated to 500-800℃, and then enters the heat transfer medium jacket to provide heat for the temperature control of the pyrolysis furnace.

8. The CO2 enrichment method according to claim 7, characterized in that: After the exothermic reaction, the pyrolysis gas at 200-300° C. discharged from the second chemical heat storage bed re-enters the combustion chamber of the pyrolysis furnace for combustion.

9. The CO2 enrichment method according to claim 7, characterized in that: The heat storage material is MgO or CaO and a matrix composite material thereof The following reactions occur during the heat storage and release process of the chemical thermal storage bed: Thermal storage process: XCO3→XO+CO2; X(OH)2→XO+H2O, where X is Mg or Ca Exothermic process: XO+CO2→XCO3; XO+H2O→X(OH)2, where X is Mg or Ca.

10. The CO2 enrichment method according to claim 7, characterized in that: The concentration of CO2 in the pyrolysis gas after the exothermic reaction is less than 20%, and the concentration of water vapor is less than 10%.

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